Ulf Ekelund

• Ekelund, Ulf; Dalene, Knut Eirik; Husøy, Anders & Tarp, Jakob (2026). Physical Activity Fully Offsets the Health Risks of Sedentary Behaviour. Medicine & Science in Sports & Exercise. ISSN 0195-9131. doi: 10.1249/MSS.0000000000004054. Full text in Research Archive
• Ekelund, Ulf; Dalene, Knut Eirik; Husøy, Anders & Tarp, Jakob (2026). Physical Activity Fully Offsets the Health Risks of Sedentary Behavior: Response to Dempsey and Colleagues. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 58(11), p. 2602–2604. doi: 10.1249/MSS.0000000000004056. Full text in Research Archive
• Husøy, Anders; Dalene, Knut Eirik; Hansen, Bjørge Hermann; Sherar, Lauren B.; Sluijs, Esther van & Anderssen, Sigmund Alfred [Show all 50 contributors for this article] (2026). Device-Measured Physical Activity, Sedentary Time, and Cardiometabolic Risk Markers in Youth: A Harmonized Individual Participant Data Meta-Analysis. JAMA pediatrics. ISSN 2168-6203. doi: 10.1001/jamapediatrics.2026.5176. Full text in Research Archive Show summary

  Importance The evidence for benefits of higher physical activity and lower sedentary time on the cardiometabolic risk profile in youth is based on cross-sectional and small prospective studies. Objective To determine the prospective associations between device-measured physical activity and sedentary time with later cardiometabolic risk profiles in youth. Data Sources The International Children’s Accelerometry Database and cohorts identified from a systematic literature search (final search performed December 2024). Study Selection Studies measured physical activity and sedentary time with an accelerometer at baseline and had prospective data on at least 1 cardiometabolic risk marker. Data Extraction and Synthesis Individual participant data were transferred to a secure network, harmonized, and analyzed as a single dataset using mixed linear regression models with different statistical adjustment based on directed acyclic graphs. Effect sizes are β coefficients per SD exposure increment. Main Outcomes and Measures Body mass index (BMI); insulin, glucose, low-density lipoprotein (LDL) cholesterol, and triglyceride levels; and systolic blood pressure, analyzed individually and as composite scores. Results Of 5432 records screened, 12 relevant studies were identified, of which 8 provided individual participant data. Fourteen cohorts (12 874 participants; mean [range] age, 10.4 [5.0-17.9] years; 6577 female [52%]) with a mean (SD) follow-up of 3.1 (2.0) years were included. Moderate to vigorous physical activity (per SD, 26 minutes/day) was inversely associated with insulin (−0.24 µIU/mL; 95% CI, −0.38 to −0.10 µIU/mL), LDL cholesterol level (−1.54 mg/dL; 95% CI, −1.93 to −0.77 mg/dL), triglyceride level (−1.77 mg/dL, 95% CI, −2.65 to −0.88 mg/dL), and the composite risk scores (−0.04; 95% CI, −0.06 to −0.02). However, moderate to vigorous physical activity was not associated with BMI (0.00; 95% CI, −0.005 to 0.005) and associated with a higher systolic blood pressure (0.25 mm Hg; 95% CI, 0.04-0.46 mm Hg). Associations for vigorous intensity activity were similar, except that there was no association with systolic blood pressure. Higher sedentary time was not associated with a worse cardiometabolic profile but was associated with lower blood glucose concentration (−0.36 mg/dL; 95% CI, −0.72 to 0 mg/dL) and lower systolic blood pressure (−0.90 mm Hg; 95% CI, −1.22 to −0.58 mm Hg). The magnitude and direction of associations were modified by modeling approach, sex, BMI, age, and follow-up time. Conclusions and Relevance Results of this harmonized individual participant data meta-analysis suggest that physical activity of moderate and vigorous intensity was beneficially associated with some cardiometabolic risk markers during childhood and adolescence. However, associations were weak, sensitive to the modeling approach, and heterogeneous across subgroups. Sedentary time is unlikely an important determinant of cardiometabolic risk in youth.

• Dalene, Knut Eirik; Lergenmuller, Simon; Stigum, Hein; Meyer, Haakon Eduard; Nystad, Wenche & Larsen, Inger Kristin [Show all 12 contributors for this article] (2026). Joint association of risk factor clustering and socioeconomic position with non-communicable disease mortality risk: a prospective cohort study of 576 299 Norwegian men and women in the NCDNOR project. BMJ Public Health. 4(2). doi: 10.1136/bmjph-2025-004101. Full text in Research Archive Show summary

  Introduction: Well-known non-communicable disease (NCD) risk factors tend to cluster, forming groups with similar ‘risk factor phenotypes’. However, the characterisation of such clusters and the role of socioeconomic position (SEP) in modifying their associations with NCDs still remain unclear. Methods: We utilised data on smoking, physical activity, alcohol consumption, body mass index, blood pressure, cholesterol and triglyceride from health examination surveys conducted in Norwegian adults from 1974 to 2019 (n=5 76 299; age 20–65 years; 64% participation; 52% women) linked to registry data on education, income and mortality (follow-up through 2020). We identified risk factor clusters using latent profile analyses and used flexible parametric survival models to estimate differences in mean age at NCD death across sex, different birth years and SEP (education and income levels). Results: We identified four distinct clusters containing 44% (‘healthy’), 45% (‘suboptimal’), 4% (‘dyslipidaemics’) and 7% (‘hypertensives’) of the study sample, respectively. During a mean follow-up of 26 years, 61 241 died from an NCD. Compared with the cluster with the healthiest profile, other clusters had markedly shorter survival across sex and different birth cohorts. However, differences were also substantially modified by SEP: we estimated that individuals with primary education or low income died several years earlier than individuals with tertiary education or high income within each of the four risk factor clusters. Conclusions: Our findings show how NCD risk factors cluster and how SEP modifies the association between this clustering and NCD mortality. The substantial influence of SEP highlights the need for public health strategies that focus not only on changing behavioural and metabolic risk factors but also on addressing socioeconomic disparities to effectively reduce the burden of NCDs.

• Vaaramo, Mikko; Kari, Jaana T.; Korpelainen, Raija; Palviainen, Teemu; Niemelä, Mikko & Ekelund, Ulf [Show all 9 contributors for this article] (2026). The Effect of Cardiorespiratory and Muscular Fitness on Healthcare Costs Among Adults: A Triangulation Study. Medicine & Science in Sports & Exercise. ISSN 0195-9131. doi: 10.1249/MSS.0000000000004115. Full text in Research Archive
• Tarp, Jakob; Sanchez-Lastra, Miguel Adriano; Dalene, Knut Eirik; Luo, Mengyun; Nguyen, Binh & Mielke, Gregore Iven [Show all 9 contributors for this article] (2026). Long-term physical activity and risk of obesity in Australian women using target-trial emulation: an OBCT study. International Journal of Epidemiology. ISSN 0300-5771. 55(5). doi: 10.1093/ije/dyag174. Full text in Research Archive Show summary

  Background: Physical activity is recommended for obesity prevention, but the evidence is limited by possible biases from reverse causation and confounding, and there are limited data on the long-term effects of physical activity through middle age on the development of obesity. Methods: We emulated a target trial by using 10 waves of observational data from the 1946–51 Australian Longitudinal Study on Women’s Health collected between 1996 and 2022. The target trial would determine the effect of randomizing women to either meeting or not meeting the World Health Organization’s recommended level of physical activity over an 18-year period on the 21-year incidence of obesity. Targeted maximum-likelihood estimation controlling for time-constant and time-varying confounders was used to emulate the target trial, assuming conditional exchangeability, positivity, consistency, and no interference. Results: In total, 779 women aged 47–52 years at study entry were included. The cumulative incidence of obesity was 9.9% [99.5% confidence interval (CI): 8.6%, 11.1%] in the scenario with 18-year adherence to the recommendation and 15.1% (99.5% CI: 12.8%, 17.4%) with consistent non-adherence (risk ratio: 1.5, 99.5% CI: 1.2, 1.9; risk difference: 5.3%-point, 99.5% CI: 2.3%, 8.3%). Each additional survey with non-adherence increased the risk of obesity (risk ratio: 1.1, 99.5% CI: 1.0, 1.1). There was no additional benefit of meeting a higher physical-activity target. Conclusion: The results of our analysis, designed specifically to address the key limitations of previous evidence, underscore the benefits of long-term adherence to the recommended ≥150 minutes of moderate-to-vigorous physical activity per week for obesity prevention in middle-aged women.

• Luo, Mengyun; Clare, Philip James; Tarp, Jakob; Dalene, Knut Eirik; Sanchez-Lastra, Miguel Adriano & Nguyen, Binh [Show all 11 contributors for this article] (2026). Dose-response interplay between light and moderate-to-vigorous physical activity on all-cause mortality risk: a causal inference analysis. British Journal of Sports Medicine. ISSN 0306-3674. doi: 10.1136/bjsports-2025-110782. Full text in Research Archive
• Ekelund, Ulf; Tarp, Jakob; Ding, Ding; Sanchez-Lastra, Miguel Adriano; Dalene, Knut Eirik & Anderssen, Sigmund Alfred [Show all 20 contributors for this article] (2026). Deaths potentially averted by small changes in physical activity and sedentary time: an individual participant data meta-analysis of prospective cohort studies. The Lancet. ISSN 0140-6736. 407(10526), p. 339–349. doi: 10.1016/S0140-6736(25)02219-6. Full text in Research Archive Show summary

  Background The effects of small, realistic changes in physical activity and sedentary behaviour on population-level mortality are unclear. We aimed to estimate the proportion of deaths preventable by 5-min and 10-min incremental increases in moderate-to-vigorous intensity physical activity (MVPA) and 30-min and 60-min reductions in daily sedentary time. Methods We did an individual participant data meta-analysis of prospective cohort studies. We included studies with device-measured physical activity and sedentary time. We estimated the proportion of deaths prevented (potential impact fractions; PIFs) by changes in (1) the approximately 20% least active participants (high-risk approach) and (2) all participants except the approximately 20% most active (population-based approach). We calculated PIFs from adjusted hazard ratios estimated for 5-min and 10-min increases in MVPA and 30-min and 60-min reductions in sedentary time from observed levels across the activity distribution. Findings We included seven cohorts from Norway, Sweden, and the USA (n=40 327; 4895 deaths). Data from the UK Biobank (n=94 719; 3487 deaths) were analysed separately. A 5-min/day increase in MVPA in the least active participants might prevent 6·0% (95% CI 4·3–7·4) of all deaths. A similar increase in MVPA in all participants except the most active might prevent 10·0% (6·3–13·4) of all deaths. Reducing sedentary time by 30 min/day might prevent 3·0% (2·0–4·1) of all deaths in the high-risk approach and 7·3% (4·8–9·6) in the population-based approach. Results from the UK Biobank were of a smaller magnitude but still substantial—eg, reducing sedentary time by 30 min/day in all except the most active participants was associated with preventing 4·5% (2·8–6·1) of total deaths. Interpretation Small and realistic increases in MVPA of 5 min/day might prevent up to 6% of all deaths in a high-risk approach and 10% of all deaths in population-based approach. Reducing sedentary time by 30 min/day might prevent a smaller, but still meaningful, proportion of deaths in the two risk scenarios.

• Paluch, Amanda E.; Matthews, Charles E.; Doherty, Aiden; Ekelund, Ulf; Evenson, Kelly R. & Galuska, Deborah A. [Show all 16 contributors for this article] (2026). Daily Steps as a Public Health Metric for Physical Activity Monitoring and Promotion. Exercise and sport sciences reviews. ISSN 0091-6331. 54(1), p. 15–25. doi: 10.1249/JES.0000000000000375. Full text in Research Archive
• Salvo, Deborah; Crochemore-Silva, Inacio; Wendt, Andrea; Tarp, Jakob; Shiroma, Eric J. & Simpson, Richard J. [Show all 19 contributors for this article] (2026). Physical activity for public health in the 21st century. Nature Medicine. ISSN 1078-8956. doi: 10.1038/s41591-026-04237-5. Full text in Research Archive
• Sanchez-Lastra, Miguel Adriano; Cruz, Borja del Pozo; Tarp, Jakob; Dalene, Knut Eirik; Nilsen, Tormod Skogstad & Ding, Ding [Show all 7 contributors for this article] (2026). Dose‒response associations of self-reported and device-measured physical activity with major adverse cardiovascular events in people with prevalent diseases. Journal of Sport and Health Science. ISSN 2095-2546. 15. doi: 10.1016/j.jshs.2025.101116. Full text in Research Archive Show summary

  Purpose: To investigate the dose-response associations of self-reported and device-measured physical activity with major adverse cardiovascular events (MACE) and cardiovascular disease (CVD) mortality in individuals with a history of CVD, type 2 diabetes mellitus (T2DM), or cancer. Methods: We analyzed data from 34,183 UK Biobank participants (CVD: n = 8703; T2DM: n = 11,623; cancer: n = 13,857; age = 60.0 ± 7.1 years, mean ± SD; 45.3% women). Physical activity was assessed using self-reports and wrist-worn accelerometers in a subsample (n = 6077). Dose‒response associations with MACE and CVD mortality were evaluated using Fine-Gray competing-risk models with penalized splines, adjusting for confounders. Results: During a median follow-up of 13.1 years, 8729 MACE and 982 CVD deaths were recorded. Self-reported physical activity showed non-linear inverse associations with MACE, with the optimal dose (nadir) observed at ≈4000 MET-min/week in CVD (hazard ratio (HR) = 0.95) and cancer (HR = 0.92) and ≈6000 MET-min/week in T2DM (HR = 0.91), compared to participants in the 5th centiles of activity. For CVD mortality, the optimal dose was observed at ≈5000 MET-min/week in CVD (HR = 0.86) and cancer (HR = 0.62), respectively. Device-measured moderate-to-vigorous intensity physical activity showed stronger dose‒response associations with MACE for T2DM (optimal dose observed at ≈200 min/week, HR = 0.88) and cancer (optimal dose at ≈700 min/week, HR = 0.27, wide confidence intervals). Conclusion: Physical activity could reduce MACE risk in people with a history of CVD, T2DM, or cancer. While a similar shape of dose-response patterns was observed across these groups, self-reported data suggested the minimal effective dose might exceed current World Health Organization recommendations. However, device-measured data supported existing guidelines for people with T2DM and cancer survivors.

• Joensuu, Laura; Lukander, Volter; Herranen, Päivi; Tynkkynen, Niko Paavo; Kujala, Urho & López-Bueno, Rubén [Show all 13 contributors for this article] (2026). Evaluation of Genetics in the Association Between Cardiorespiratory Fitness and Health: Insights from a Genome‐Wide Polygenic Score for Cardiorespiratory Fitness in the FinnGen and HUNT cohorts. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. doi: 10.1111/sms.70291. Full text in Research Archive
• Ding, Ding; Nguyen, Binh; Nau, Tracy; Luo, Mengyun; Cruz, Borja del Pozo & Dempsey, Paddy C. [Show all 20 contributors for this article] (2025). Daily steps and health outcomes in adults: a systematic review and dose-response meta-analysis. The Lancet Public Health. ISSN 2468-2667. 10(8), p. e668–e681. doi: 10.1016/S2468-2667(25)00164-1. Full text in Research Archive Show summary

  Background Despite the rapid increase in evidence from the past decade on daily steps and health-related outcomes, existing systematic reviews primarily focused on few outcomes, such as all-cause mortality. This study synthesised the prospective dose-response relationship between daily steps and health outcomes including all-cause mortality, cardiovascular disease, cancer, type 2 diabetes, cognitive outcomes, mental health outcomes, physical function, and falls. Methods For this systematic review and meta-analysis, we searched PubMed and EBSCO CINAHL for literature published between Jan 1, 2014, and Feb 14, 2025, supplemented by other search strategies. Eligible prospective studies examined the relationship between device-measured daily steps and health outcomes among adults without restrictions on language or publication type. Pairs of reviewers (BN, KO, ML, and TN) independently did the study selection, data extraction, and risk of bias assessment using the 9-point Newcastle-Ottawa Scale. Hazard ratios (HRs) from individual studies were synthesised using random-effects dose-response meta-analysis where possible. Certainty of evidence was assessed using GRADE. This trial is registered with PROSPERO (CRD42024529706). Findings 57 studies from 35 cohorts were included in the systematic review and 31 studies from 24 cohorts were included in meta-analyses. For all-cause mortality, cardiovascular disease incidence, dementia, and falls, an inverse non-linear dose-response association was found, with inflection points at around 5000–7000 steps per day. An inverse linear association was found for cardiovascular disease mortality, cancer incidence, cancer mortality, type 2 diabetes incidence, and depressive symptoms. Based on our meta-analyses, compared with 2000 steps per day, 7000 steps per day was associated with a 47% lower risk of all-cause mortality (HR 0·53 [95% CI 0·46–0·60]; I2=36·3; 14 studies), a 25% lower risk of cardiovascular disease incidence (HR 0·75 [0·67–0·85]; I2=38·3%; six studies), a 47% lower risk of cardiovascular disease mortality (HR 0·53 [0·37–0·77]; I2=78·2%; three studies), a non-significant 6% lower risk of cancer incidence (HR 0·94 [0·87–1·01]; I2=73·7%; two studies), a 37% lower risk of cancer mortality (HR 0·63 [0·55–0·72]; I2=64·5%; three studies), a 14% lower risk of type 2 diabetes (HR 0·86 [0·74–0·99]; I2=48·5%; four studies), a 38% lower risk of dementia (HR 0·62 [0·53–0·73]; I2=0%; two studies), a 22% lower risk of depressive symptoms (HR 0·78 [0·73–0·83]; I2=36·2%; three studies), and a 28% lower risk of falls (HR 0·72 [0·65–0·81]; I2=47·5%; four studies). Studies on physical function (not based on meta-analysis) reported similar inverse associations. The evidence certainty was moderate for all outcomes except for cardiovascular disease mortality (low), cancer incidence (low), physical function (low), and falls (very low). Interpretation Although 10 000 steps per day can still be a viable target for those who are more active, 7000 steps per day is associated with clinically meaningful improvements in health outcomes and might be a more realistic and achievable target for some. The findings of the study should be interpreted in light of limitations, such as the small number of studies available for most outcomes, a lack of age-specific analysis and biases at the individual study level, including residual confounding.

• Tornquist, Debora; Tornquist, Luciana; Crochemore-Silva, Inácio; Mielke, Grégore Iven; Ekelund, Ulf & Hallal, Pedro Curi [Show all 7 contributors for this article] (2025). Associations of Early Childhood Correlates With Device-Measured Physical Activity in the First Years of Life: Findings From the 2015 Pelotas (Brazil) Birth Cohort Study. Journal of Physical Activity and Health. ISSN 1543-3080. 22(8), p. 1028–1041. doi: 10.1123/jpah.2024-0565. Full text in Research Archive Show summary

  Background: The study aimed to examine the associations between breastfeeding, home environmental and childcare characteristics, and maternal and child behaviors and physical activity (PA) in the first years of life in the 2015 Pelotas (Brazil) Birth Cohort. Methods: PA was measured with wrist accelerometers at 1 (n = 2974), 2 (n = 2645), and 4 years (n = 2955), and PA trajectories were estimated using group-based trajectory modeling (n = 1798). Results: At the age of 1 year, partially breastfed children had higher levels of PA, whereas children with excessive screen time had lower PA. At 2 years, children whose mothers went for leisure walks had higher levels of PA, and children who attended childcare had lower levels of PA. At 4 years, higher PA was associated with breastfeeding for >6 months, maternal leisure-time PA, and having ≥2 siblings, whereas attendance at public childcare was associated with lower PA. Attendance at childcare in at least one follow-up and public childcare reduced the probability of the child presenting a trajectory of high PA in the early years. Children of mothers who performed some leisure-time PA and other leisure-time PA (except walking) in more than 1 follow-up were more likely to present a high PA trajectory. Conclusions: Breastfeeding, childcare, number of siblings, maternal PA, and screen time were shown to be correlates of PA levels in early childhood.

• Cadenas-Sanchez, Cristina; Sanchez-Lastra, Miguel Adriano; Tarp, Jakob; Ekelund, Ulf & Dalene, Knut Eirik (2025). Occupational physical activity and incidence and mortality of 14 cancers in 404,249 adults. Nature Communications. 16. doi: 10.1038/s41467-025-65326-6. Full text in Research Archive Show summary

  Leisure physical activity is considered protective against several cancers, but the impact of physical activity at work remains unclear. We analyze data from over 400,000 Norwegian adults followed for a median of 27 years to examine how different levels of occupational physical activity are associated with cancer incidence and mortality. Participants report their typical work activity as sedentary, walking, walking-and-lifting, or heavy labor. Here we show that individuals with more physically active jobs have a lower risk of developing several cancers (i.e., endometrial, colon, breast, rectal, and prostate), and to a lesser extent, the risk of breast cancer mortality. However, occupational physical activity is also associated with increased risk of esophageal and kidney cancer death. These findings suggest that occupational physical activity may lower the incidence of some cancers but are associated with a higher mortality from other cancer types. Understanding these patterns could help tailor public health recommendations related to physical activity and occupational health.

• Husøy, Anders; Kolle, Elin; Steene-Johannessen, Jostein; Andersen, Lars Bo; Ekelund, Ulf & Anderssen, Sigmund Alfred (2025). Tracking of device-measured sedentary time, cardiorespiratory fitness, and cardiometabolic risk factors from childhood to young adulthood. American Journal of Preventive Cardiology. 24. doi: 10.1016/j.ajpc.2025.101313. Full text in Research Archive Show summary

  Background The tracking of clustered cardiometabolic risk from childhood to young adulthood, i.e., whether an unfavourable cardiometabolic risk profile persists from childhood into young adulthood, remain uncertain and has previously not included factors like sedentary time and cardiorespiratory fitness. Methods We used longitudinal data from the Physical Activity among Norwegian Children Studies (PANCS), where 731 participants participated at age 9 (2005–2006) and 258 of these again at age 24 (2019–2021). Multiple imputation was performed for all eligible participants at age 24 (n = 708). The cardiometabolic risk factors comprised body mass index (BMI), waist circumference, device-measured sedentary time, directly measured peak oxygen uptake (VO2peak), systolic blood pressure, LDL-cholesterol, insulin, high-sensitivity CRP, and a clustered risk Z-score. Tracking was analysed using regression models. Results Waist circumference and BMI demonstrated strong tracking, whereas moderate tracking was observed for VO2peak, LDL-cholesterol, systolic blood pressure, and clustered cardiometabolic risk. Insulin, high-sensitivity CRP, and sedentary time exhibited no tracking. Unfavourable childhood levels of risk factors demonstrating moderate to strong tracking were highly predictive, with those in the least favourable quartile of clustered risk at age 9 almost six times more likely than their peers to be in the least favourable quartile at age 24 years. Tracking was generally similar between sexes, but waist circumference tracked somewhat stronger among females while VO2peak tracked stronger among males. Conclusions Several cardiometabolic risk factors demonstrated moderate to strong tracking from childhood to young adulthood, supporting early intervention. However, sedentary behaviour may be less stable and easier to modify compared with more stable cardiometabolic risk factors.

• Atkin, Andrew J.; Sherar, Lauren B.; Ekelund, Ulf; Hansen, Bjørge Hermann; Andersen, Lars Bo & Anderssen, Sigmund Alfred [Show all 17 contributors for this article] (2025). Age-related change in children’s physical activity and sedentary time: The International Children’s Accelerometry Database (ICAD). PLOS ONE. 20(9). doi: 10.1371/journal.pone.0327394. Full text in Research Archive Show summary

  Background Many young people fail to achieve the minimum recommended amount of physical activity to benefit their health. Understanding the nature of age-related changes in behaviour and how this varies for population sub-groups is informative for intervention design. The aim of this study was to describe age-related changes in physical activity and sedentary time and examine variability in patterns of change across demographic sub-groups. Methods Data are from 13 studies in the International Children’s Accelerometry Database (ICAD), all of which provided ≥2 waves of waist-worn accelerometer data. Annual change in sedentary time, light intensity physical activity (LPA) and moderate to vigorous intensity physical activity (MVPA) were estimated using three level mixed effects linear regression models, using participant age as the exposure variable. In interaction models, we examined whether changes in behaviour differed by day of the week (weekday/ weekend), age at baseline assessment (<10/ ≥ 10 years), sex, weight category, maternal education and ethnicity. Results In total, 6567 participants provided two or more waves of valid accelerometer data (44.5% boys, mean (SD) baseline age 10.6 (2.1) years (range 4.1–15.8 years)). Across the week and for all studied sub-groups, sedentary time increased by approximately 25 minutes/day/year of age, LPA decreased by approximately 22 minutes/day/year of age and MVPA decreased by approximately 3 minutes/day/year of age. The annual increase in sedentary time was greater in girls compared to boys (β (95% confidence interval) change (min) for each additional year of age: girls, 25.9 (25.4, 26.4); boys, 23.6 (23.0, 24.2)) and in adolescents compared to children (adolescents, 27.0 (26.5, 27.6); children, (23.5 (22.9, 24.2)). The annual decrease in MVPA was greater in boys compared to girls (boys, −2.7 (−3.0, −2.5); girls, −2.2 (−2.4, −2.0)) and at the weekend compared to during the week (weekend, −3.0 (−3.3, −2.8); weekday −2.3 (−2.5, −2.1)). Conclusion Accelerometer assessed sedentary time increased whilst LPA and MVPA decreased during childhood and adolescence. This overall pattern was observed across the week and in all studied sub-groups, but small differences in the magnitude of changes can be used to guide the timing and targeting of behaviour change interventions, such as designing physical activity interventions which focus on weekends where a child’s time is less structured.

• McGrosky, Amanda; Luke, Amy; Arab, Leonore; Bedu-Addo, Kweku; Bonomi, Alberto G. & Bovet, Pascal [Show all 98 contributors for this article] (2025). Energy expenditure and obesity across the economic spectrum. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 122(29). doi: 10.1073/pnas.2420902122. Full text in Research Archive Show summary

  Global economic development has been associated with an increased prevalence of obesity and related health problems. Increased caloric intake and reduced energy expenditure are both cited as development-related contributors to the obesity crisis, but their relative importance remains unresolved. Here, we examine energy expenditure and two measures of obesity (body fat percentage and body mass index, BMI) for 4,213 adults from 34 populations across six continents and a wide range of lifestyles and economies, including hunter-gatherer, pastoralist, farming, and industrialized populations. Economic development was positively associated with greater body mass, BMI, and body fat, but also with greater total, basal, and activity energy expenditure. Body size–adjusted total and basal energy expenditures both decreased approximately 6 to 11% with increasing economic development, but were highly variable among populations and did not correspond closely with lifestyle. Body size–adjusted total energy expenditure was negatively, but weakly, associated with measures of obesity, accounting for roughly one-tenth of the elevated body fat percentage and BMI associated with economic development. In contrast, estimated energy intake was greater in economically developed populations, and in populations with available data (n = 25), the percentage of ultraprocessed food in the diet was associated with body fat percentage, suggesting that dietary intake plays a far greater role than reduced energy expenditure in obesity related to economic development.

• Bian, Wenxin; Ahmadi, Matthew N.; Biswas, Raaj Kishore; Blodgett, Joanna M.; Atkin, Andrew J. & Chan, Hsiu-Wen [Show all 28 contributors for this article] (2025). Device-Measured Sleep Characteristics, Daily Step Count, and Cardiometabolic Health Markers: Findings From the Prospective Physical Activity, Sitting, and Sleep (ProPASS) Consortium. Circulation. Cardiovascular Quality and Outcomes. ISSN 1941-7713. 18(8), p. e011873–e011873. doi: 10.1161/circoutcomes.124.011873. Full text in Research Archive Show summary

  BACKGROUND: Sleep and physical activity (PA) are important lifestyle-related behaviors that impact cardiometabolic health. This study investigated the joint associations of daily step count and sleep patterns (regularity and duration) with cardiometabolic biomarkers in adults. METHODS: We conducted a cross-sectional study using pooled data from the Prospective PA, Sitting, and Sleep Consortium, comprising 6 cohorts across Europe and Australia with thigh-worn accelerometry data collected between 2011 and 2021. The sleep regularity index, a metric that quantifies day-to-day sleep consistency, sleep duration (h/d), and steps (per day), was derived from the accelerometer data and categorized based on tertiles and sleep duration guidelines. We used multivariate generalized linear models to examine joint associations of sleep patterns and total daily step count with individual cardiometabolic biomarkers, including body mass index, waist circumference, total cholesterol, HDL (high-density lipoprotein) cholesterol, triglycerides, HbA1c (glycated hemoglobin), and a composite cardiometabolic health score (mean of the 6 standardized biomarker Z scores). RESULTS: The sample included 11 903 adults with a mean±SD age of 54.7±9.5 years, 54.9% female, a sleep regularity index of 78.7±10.4, and 10 206.4±3442.2 daily steps. Lower PA (<8475 steps/d) combined with either lower sleep regularity (sleep regularity index <75.9) or short sleep duration (<7 h/d) was associated with the least favorable composite cardiometabolic health. The corresponding Z scores (95% CI) were 0.34 (0.30–0.38) and 0.26 (0.22–0.31) compared with those with optimal sleep (sleep regularity index >84.5 or 7–8 h/d) and high step count (>11 553 steps/d). The combination of low sleep regularity and low daily steps was associated with higher body mass index (2.92 [2.61–3.24] kg/m 2 ), waist circumference (8.58 [7.78–9.38] cm), total cholesterol (0.15 [0.07–0.23] mmol/L), and lower HDL levels (0.17 [0.14–0.2] mmol/L), regardless of sleep duration. The combination of short sleep and low step count had the strongest unfavorable associations for body mass index (2.31 [1.98–2.65] kg/m 2 ) and waist circumference (7.01 [6.15–7.87] cm). CONCLUSIONS: Our findings suggest that the potential deleterious associations of irregular or insufficient sleep with cardiometabolic health outcomes may be exaggerated by lower daily PA. Investigation of the prospective joint association of sleep patterns and PA with cardiometabolic health may be warranted.

• Lam, Thao Minh; Aarestrup, Julie; Akker, Erica L. T. van den; Baker, Jennifer L.; Banik, Anna & Berntzen, Bram J. [Show all 56 contributors for this article] (2025). Advancing knowledge, maps and tools to address obesity and related socio-economic disparities in Europe: the OBCT project. Global health action. ISSN 1654-9716. 18(1). doi: 10.1080/16549716.2025.2517492. Full text in Research Archive Show summary

  The steady rise in overweight and obesity in Europe disproportionately affects people and communities with a lower socio-economic position (SEP). Many obesity prevention approaches exist, but these have had limited reach and unsatisfactory effects thus far, especially in low-SEP populations. In this context, there is a need for implementation of effective individual-level and population-based preventive strategies that also tackle health inequalities. Effective strategies require consideration of the complex and cross-domain obesity risk factors across the life course. Feasible and acceptable strategies require multisectoral collaborations and innovative approaches, including a whole-of community and systems perspective. With the Horizon Europe-funded OBCT project, we aim to quantify the relative contribution of biological, socio-cultural and built environment factors to obesity and the interactions of these risks within and across various life course stages; and translate the resulting knowledge into practical, equitable, and effective tools for action. These tools will include: a comprehensive obesity risk screener; a map of the obesogenicity of neighbourhood environments as well as trends in obesity prevalence of each European country; recommendations for lifestyle behaviours (diet, physical activity, sedentary behaviours) to prevent obesity during key life transition stages; a decision support dashboard for policy makers; and co-developed toolboxes to support implementation of policy recommendations in low-SEP communities. OBCT’s outputs will highlight the areas and domains in which obesity should be targeted and will empower the research community, policymakers, health professionals and residents in Europe to adapt and implement strategies to effectively reduce obesity risk, particularly in low-SEP communities.

• Bajunaid, Rania; Niu, Chaoqun; Hambly, Catherine; Liu, Zongfang; Yamada, Yosuke & Aleman-Mateo, Heliodoro [Show all 98 contributors for this article] (2025). Predictive equation derived from 6,497 doubly labelled water measurements enables the detection of erroneous self-reported energy intake. Nature Food. 6, p. 58–71. doi: 10.1038/s43016-024-01089-5. Full text in Research Archive Show summary

  Nutritional epidemiology aims to link dietary exposures to chronic disease, but the instruments for evaluating dietary intake are inaccurate. One way to identify unreliable data and the sources of errors is to compare estimated intakes with the total energy expenditure (TEE). In this study, we used the International Atomic Energy Agency Doubly Labeled Water Database to derive a predictive equation for TEE using 6,497 measures of TEE in individuals aged 4 to 96 years. The resultant regression equation predicts expected TEE from easily acquired variables, such as body weight, age and sex, with 95% predictive limits that can be used to screen for misreporting by participants in dietary studies. We applied the equation to two large datasets (National Diet and Nutrition Survey and National Health and Nutrition Examination Survey) and found that the level of misreporting was 27.4%. The macronutrient composition from dietary reports in these studies was systematically biased as the level of misreporting increased, leading to potentially spurious associations between diet components and body mass index.

• Schumann, Moritz; Feuerbacher, Joshua F.; Heinrich, Lars; Olvera-Rojas, Marcos; Sclafani, Alessandro & Brønd, Jan Christian [Show all 13 contributors for this article] (2025). Using Free-Living Heart Rate Data as an Objective Method to Assess Physical Activity: A Scoping Review and Recommendations by the INTERLIVE-Network Targeting Consumer Wearables. Sports Medicine. ISSN 0112-1642. 55, p. 275–300. doi: 10.1007/s40279-024-02159-1. Full text in Research Archive
• Husøy, Anders; Kolle, Elin; Steene-Johannessen, Jostein; Andersen, Lars Bo; Anderssen, Sigmund Alfred & Ekelund, Ulf (2025). Prospective Associatons of Physical Activity and Sedentary Time in Adolescence with Cardiometabolic Risk in Young Adulthood. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 57(3), p. 535–543. doi: 10.1249/MSS.0000000000003595. Full text in Research Archive Show summary

  Purpose The relationship between sedentary time, physical activity, and cardiometabolic risk factors during the transition from adolescence to adulthood remains uncertain. We examined the prospective associations of sedentary time and physical activity at age 15 yr with cardiometabolic risk markers at age 24 yr. Methods We used data from the Physical Activity among Norwegian Children Studies. Sedentary time, moderate-to-vigorous physical activity (MVPA), and vigorous physical activity (VPA) were measured by accelerometry. Outcomes included body mass index (BMI), waist circumference, visceral fat, maximal oxygen uptake (V̇O2max), systolic blood pressure, LDL-cholesterol, insulin, high-sensitivity C-reactive protein, and a clustered risk Z-score. The prospective associations were modeled through regression. Results A total of 731 boys and girls participated at ages 9 yr (2005–2006) and 15 yr (2011–2012), and 258 of these participated again at age 24 yr (2019–2021). Multiple imputation was performed for all eligible individuals (n = 708). Each standard deviation increase (minutes per day) in sedentary time at age 15 yr was associated with lower V̇O2max at age 24 yr (β = −1.6 mL·kg−1·min−1; 95% confidence interval (CI), −2.8 to −0.5). Each standard deviation increase (minutes per day) in MVPA (β = 1.6 mL·kg−1·min−1; 95% CI, 0.8 to 2.4) and VPA (β = 1.6 mL·kg−1·min−1; 95% CI, 0.8 to 2.4) at age 15 yr were associated with higher V̇O2max at age 24 yr. VPA in adolescence was further inversely associated with visceral fat mass (β = −41 g; 95% CI, −78 to −3), insulin level (β = −4.3 pmol·L−1; 95% CI, −8.2 to −0.4), and the clustered risk Z-score (β = −0.09; 95% CI, −0.18 to −0.01) in young adulthood. Childhood BMI modified the association of both MVPA and VPA with clustered risk, with the greatest magnitude of association observed in the highest BMI tertile. Conclusions Physical activity, especially of vigorous intensity, during adolescence appears to beneficially affect cardiometabolic health in young adulthood. These health benefits may be most pronounced among overweight/obese youth.

• Zaccardi, Francesco; Rowlands, Alex V.; Dempsey, Paddy C.; Razieh, Cameron; Henson, Joe & Goldney, Jonathan [Show all 15 contributors for this article] (2025). Interplay between physical activity volume and intensity with modeled life expectancy in women and men: A prospective cohort analysis. Journal of Sport and Health Science. ISSN 2095-2546. 14. doi: 10.1016/j.jshs.2024.100970. Full text in Research Archive Show summary

  Background There is a lack of research examining the interplay between objectively measured physical activity volume and intensity with life expectancy. The purpose of the study was to investigate the interplay between objectively measured PA volume and intensity profiles with modeled life expectancy in women and men within the UK Biobank cohort study and interpret findings in relation to brisk walking. Methods Individuals from UK Biobank with wrist-worn accelerometer data were included. The average acceleration and intensity gradient were extracted to describe the physical activity volume and intensity profile. Mortality data were obtained from national registries. Adjusted life expectancies were estimated using parametric flexible survival models. Results 40,953 (57.1%) women (median age = 61.9 years) and 30,820 (42.9%) men (63.1 years) were included. Over a median follow-up of 6.9 years, there were 1719 (2.4%) deaths (733 in women; 986 in men). At 60 years, life expectancy was progressively longer for higher physical activity volume and intensity profiles, reaching 95.6 years in women and 94.5 years in men at the 90th centile for both volume and intensity, corresponding to 3.4 additional years (95% confidence interval (95%CI): 2.4–4.4) in women and 4.6 additional years (95%CI: 3.6–5.6) in men compared to those at the 10th centiles. An additional 10-min or 30-min daily brisk walk was associated with 0.9 (95%CI: 0.5–1.3) and 1.4 years (95%CI: 0.9–1.9) longer life expectancy, respectively, in inactive women; and 1.4 years (95%CI: 1.0–1.8) and 2.5 (95%CI: 1.9–3.1) in inactive men. Conclusion Higher physical activity volumes were associated with longer life expectancy, with a higher physical activity intensity profile further adding to a longer life. Adding as little as a 10-min brisk walk to daily activity patterns may result in a meaningful benefit to life expectancy.

• Joensuu, Laura; Koivunen, Kaisa; Tynkkynen, Niko Paavo; Palviainen, Teemu; Kaprio, Jaakko & Consortium, FinnGen [Show all 12 contributors for this article] (2025). Genetic liability to sedentary behaviour and cardiovascular disease incidence in the FinnGen and HUNT cohorts. British Journal of Sports Medicine. ISSN 0306-3674. 59(11), p. 783–790. doi: 10.1136/bjsports-2024-109491. Full text in Research Archive Show summary

  Objective: Energy-saving sedentary behaviour may be an evolutionarily selected trait that is no longer advantageous. We investigated the associations between genetic liability to sedentary behaviour and the incidence of the most common cardiovascular disease (CVD). Methods: We constructed and validated a genome-wide polygenic score for leisure screen time (PGS LST) as a measure of genetic liability to sedentary behaviour. We performed survival analyses between higher PGS LST and register-based CVDs using the FinnGen cohort (N=293 250–333 012). Replication and exploratory analyses were conducted in an independent Norwegian Trøndelag Health Study (HUNT) cohort (N=35 289). Results: In FinnGen, each SD increase in PGS LST was associated with a higher risk of incident CVD (HR: 1.05 (95% CI 1.05 to 1.06)) (168 770 cases over 17 101 133 person-years). The magnitudes of association for the three most common CVDs were 1.09 ((95% CI 1.08 to 1.09), 1.06 ((95% CI 1.05 to 1.07) and 1.05 ((95% CI 1.04 to 1.06) for hypertensive disease, ischaemic heart disease and cerebrovascular disease, respectively. Those in the top decile of PGS LST had 21%, 35%, 26% and 19% higher risk of any CVD, hypertensive disease, ischaemic heart disease and cerebrovascular disease, respectively, than those in the bottom decile. Associations were replicated in HUNT and remained independent of covariates (socioeconomic status, body mass index and smoking) except for cerebrovascular disease. Besides direct effects, reduced physical activity served as a potential mediating pathway for the observed associations. Conclusions: We found that genetic liability to sedentary behaviour is associated with incident CVD, although effect sizes with current PGS remained small. These findings suggest that genetic liability to sedentary behaviour is an under-recognised driver of common CVDs.

• Wendt, Andrea; Leite, Giulia Salaberry; Contreira, Renata; Mielke, Grégore Iven; Horta, Bernardo Lessa & Motta, Janaína Vieira Dos Santos [Show all 19 contributors for this article] (2025). Lessons from 13 years of accelerometry measurements in five Brazilian cohorts: methodological aspects. Cadernos de Saúde Pública. ISSN 0102-311X. 41(3), p. e00011724–e00011724. doi: 10.1590/0102-311XEN011724. Full text in Research Archive
• Sanchez-Lastra, Miguel Adriano; Cruz, Borja del Pozo; Ekelund, Ulf; Tarp, Jakob & Ding, Ding (2025). Physical Activity and Life Expectancy Free of Cancer: Prospective Evidence From the UK Biobank Study. Journal of Physical Activity and Health. ISSN 1543-3080. 22(5), p. 636–639. doi: 10.1123/jpah.2024-0390. Full text in Research Archive
• Sanchez-Lastra, Miguel Adriano; Strain, Tessa; Ding, Ding; Dalene, Knut Eirik; Cruz, Borja del Pozo & Ekelund, Ulf [Show all 7 contributors for this article] (2025). Associations of adiposity and device-measured physical activity with cancer incidence: UK Biobank prospective cohort study. Journal of Sport and Health Science. ISSN 2095-2546. 14. doi: 10.1016/j.jshs.2024.101018. Full text in Research Archive
• Ricardo, Luiza I.C.; Wendt, Andrea; Tornquist, Debora; Gonçalves, Helen; Wehrmeister, Fernando & Silva, Bruna Gonçalves C. da [Show all 15 contributors for this article] (2024). Gender Gap for Accelerometry-Based Physical Activity Across Different Age Groups in 5 Brazilian Cohort Studies. Journal of Physical Activity and Health. ISSN 1543-3080. 21(11), p. 1158–1166. doi: 10.1123/jpah.2024-0018. Full text in Research Archive Show summary

  Objectives: This study aims to evaluate the gender inequalities in accelerometer-based physical activity (PA) across different age groups using data from 5 Pelotas (Brazil) cohorts. Methods: The data come from 4 birth cohort studies, covering all live births in the urban area of Pelotas for each respective year (1982, 1993, 2004, and 2015), and the Como vai? cohort study focusing on 60 years and above. Raw accelerometry data were collected on the nondominant wrist using GENEActive/ActiGraph devices and processed with the GGIR package. Overall PA was calculated at ages 1, 2, 4, 6, 11, 15, 18, 23, 30, and 60+ years, while moderate to vigorous PA was calculated from 6 years onward. Absolute (difference) and relative (ratio) gender inequalities were calculated and intersectionality between gender and wealth was also evaluated. Results: The sample sizes per cohort ranged from 965 to 3462 participants. The mean absolute gender gap was 19.3 minutes (95% confidence interval, 12.7–25.9), with the widest gap at 18 years (32.9 min; 95% confidence interval, 30.1–35.7) for moderate to vigorous PA. The highest relative inequality was found in older adults (ratio 2.0; 95% confidence interval, 1.92–2.08). Our intersectionality results showed that the poorest men being the most active group, accumulating around 60 minutes more moderate to vigorous PA per day compared with the wealthiest women at age 18. Conclusions: Men were more physically active than women in all ages evaluated. PA gender inequalities start at an early age and intensify in transition periods of life. Relative inequalities were marked among older adults.

• Joensuu, Laura; Koivunen, Kaisa; Tynkkynen, Niko Paavo; Palviainen, Teemu; Kaprio, Jaakko & Klevjer, Marie [Show all 11 contributors for this article] (2024). Genetic liability to sedentary behavior increases the risk of cardiovascular disease incidence: Evidence from the FinnGen cohort with 293,250 individuals. medRxiv. doi: 10.1101/2024.06.20.24309213. Full text in Research Archive
• Martinez-Gomez, David; Rodriguez-Artalejo, Fernando; Ding, Ding; Ekelund, Ulf & Cabanas-Sanchez, Veronica (2024). Trends in the association between meeting the physical activity guidelines and risk of mortality in US adults. Progress in cardiovascular diseases. ISSN 0033-0620. 83, p. 116–123. doi: 10.1016/j.pcad.2024.02.011. Full text in Research Archive Show summary

  Objective: To examine the trends in the association between meeting the physical activity (PA) guidelines and mortality in adults. Methods: We included seventeen annual representative samples of US adults 1998–2014 (n = 482,756) and all-cause and cause-specific mortality ascertained through December 2019. Participants were grouped according to PA Guidelines: 150 or more min/week in aerobic PA and muscle-strengthening activities 2 or more times/week. To provide further context, we also examined the trends in mortality risk associated with other modifiable health factors. Results: Meeting the PA guidelines was associated with lower 5-year mortality risk (HR = 0.59, 95%CI, 0.55, 0.63) based on the pooled analyses. We consistently observed an inverse association in all years, but there was a nonsignificant trend association (P for trend = 0.305) between meeting PA guidelines and 5-year mortality across the seventeen annual surveys. Meeting aerobic (HR = 0.58, 95%CI, 0.56, 0.61) and muscle-strengthening (HR = 0.86, 95%CI, 0.81, 0.90) guidelines were independently associated with 5-year mortality risk in pooled analyses, without any evidence for trends in the associations. Similar results were found with cause-specific mortality and 10-year mortality risk. In pooled analyses, attaining a high educational level, body mass index

• Sluijs, Esther M.F. Van; Ekelund, Ulf; Hallal, Pedro C.; Hansen, Bjørge Hermann; Panter, Jenna & Salmon, Jo [Show all 9 contributors for this article] (2024). Family Car Ownership: Driving Inactivity in Young People? Cross-Sectional and Longitudinal Analyses in the International Children's Accelerometry Database. Journal of Physical Activity and Health. ISSN 1543-3080. 21(12), p. 1391–1400. doi: 10.1123/jpah.2024-0044. Full text in Research Archive Show summary

  Background: Ubiquitous car ownership may affect children’s activity and health. We assessed the cross-sectional and longitudinal associations between household car ownership and children’s daily time spent sedentary (SED) and in moderate to vigorous physical activity (MVPA). Methods: Pooled cohort data were from the International Children’s Accelerometry Database. Outcome measures were average daily accelerometer-measured SED and MVPA (in minutes per day). Exposures were household car ownership (none, 1, and ≥2) and change in car ownership. Associations were examined using multivariable mixed-effects linear regression. Results: Mean age of participants (N = 4193) was 10.4 years (SD = 2.0), 53.4% were girls, and mean follow-up duration (N = 1333) was 3.3 years (SD = 1.1). Cross-sectionally, household car ownership was associated with higher SED (vs none: 1 car: β = 14.1 min/d, 95% CI, 6.7–21.5; ≥2 cars: 12.8, 95% CI, 5.3–20.4) and lower MVPA (vs none: 1 car: β = –8.8, 95% CI, −11.9 to −5.7; ≥2 cars: β = –8.8, 95% CI, −12.0 to −5.7). Associations were stronger in boys than girls and in children from lower socioeconomic backgrounds (SED only). Prospectively, there were no associations with increased car ownership. Reductions in household car ownership (of which 93.1% had ≥ 2 cars at baseline) were associated with a greater reduction in MVPA (vs no change: β = −8.4, 95% CI, −13.9 to −3.0) but not SED. Conclusions: Children in households with car access were more SED and less active than those without. Losing access to a second car was associated with greater decreases in MVPA, potentially related to losing access to activity-enabling environments. Reducing car access and use are important public health targets (eg, reducing air pollution), but their potential impact on children’s activity opportunities should be mitigated.

• Blodgett, Joanna M.; Ahmadi, Matthew N.; Atkin, Andrew J; Pulsford, Richard M.; Rangul, Vegar & Chastin, Sebastian [Show all 26 contributors for this article] (2024). Device-Measured 24-Hour Movement Behaviors and Blood Pressure: A 6-Part Compositional Individual Participant Data Analysis in the ProPASS Consortium. Circulation. ISSN 0009-7322. 151(2), p. 159–170. doi: 10.1161/CIRCULATIONAHA.124.069820. Full text in Research Archive Show summary

  Background: Blood pressure (BP)–lowering effects of structured exercise are well-established. Effects of 24-hour movement behaviors captured in free-living settings have received less attention. This cross-sectional study investigated associations between a 24-hour behavior composition comprising 6 parts (sleeping, sedentary behavior, standing, slow walking, fast walking, and combined exercise-like activity [eg, running and cycling]) and systolic BP (SBP) and diastolic BP (DBP). Methods: Data from thigh-worn accelerometers and BP measurements were collected from 6 cohorts in the Prospective Physical Activity, Sitting and Sleep consortium (ProPASS) (n=14 761; mean±SD, 54.2±9.6 years). Individual participant analysis using compositional data analysis was conducted with adjustments for relevant harmonized covariates. Based on the average sample composition, reallocation plots examined estimated BP reductions through behavioral replacement; the theoretical benefits of optimal (ie, clinically meaningful improvement in SBP [2 mm Hg] or DBP [1 mm Hg]) and minimal (ie, 5-minute reallocation) behavioral replacements were identified. Results: The average 24-hour composition consisted of sleeping (7.13±1.19 hours), sedentary behavior (10.7±1.9 hours), standing (3.2±1.1 hours), slow walking (1.6±0.6 hours), fast walking (1.1±0.5 hours), and exercise-like activity (16.0±16.3 minutes). More time spent exercising or sleeping, relative to other behaviors, was associated with lower BP. An additional 5 minutes of exercise-like activity was associated with estimated reductions of –0.68 mm Hg (95% CI, –0.15, –1.21) SBP and –0.54 mm Hg (95% CI, –0.19, 0.89) DBP. Clinically meaningful improvements in SBP and DBP were estimated after 20 to 27 minutes and 10 to 15 minutes of reallocation of time in other behaviors into additional exercise. Although more time spent being sedentary was adversely associated with SBP and DBP, there was minimal impact of standing or walking. Conclusions: Study findings reiterate the importance of exercise for BP control, suggesting that small additional amounts of exercise are associated with lower BP in a free-living setting.

• Zhou, Bin; Cesare, Mariachiara Di; Aguilar-Salinas, Carlos A; Ahmad, Nor Ani; Bovet, Pascal & Chen, Zhengming [Show all 51 contributors for this article] (2024). General and abdominal adiposity and hypertension in eight world regions: a pooled analysis of 837 population-based studies with 7·5 million participants. The Lancet. ISSN 0140-6736. 404(10455), p. 851–863. doi: 10.1016/S0140-6736(24)01405-3. Full text in Research Archive Show summary

  Background: Adiposity can be measured using BMI (which is based on weight and height) as well as indices of abdominal adiposity. We examined the association between BMI and waist-to-height ratio (WHtR) within and across populations of different world regions and quantified how well these two metrics discriminate between people with and without hypertension. Methods: We used data from studies carried out from 1990 to 2023 on BMI, WHtR and hypertension in people aged 20–64 years in representative samples of the general population in eight world regions. We graphically compared the regional distributions of BMI and WHtR, and calculated Pearson's correlation coefficients between BMI and WHtR within each region. We used mixed-effects linear regression to estimate the extent to which WHtR varies across regions at the same BMI. We graphically examined the prevalence of hypertension and the distribution of people who have hypertension both in relation to BMI and WHtR, and we assessed how closely BMI and WHtR discriminate between participants with and without hypertension using C-statistic and net reclassification improvement (NRI). Findings: The correlation between BMI and WHtR ranged from 0·76 to 0·89 within different regions. After adjusting for age and BMI, mean WHtR was highest in south Asia for both sexes, followed by Latin America and the Caribbean and the region of central Asia, Middle East and north Africa. Mean WHtR was lowest in central and eastern Europe for both sexes, in the high-income western region for women, and in Oceania for men. Conversely, to achieve an equivalent WHtR, the BMI of the population of south Asia would need to be, on average, 2·79 kg/m2 (95% CI 2·31–3·28) lower for women and 1·28 kg/m2 (1·02–1·54) lower for men than in the high-income western region. In every region, hypertension prevalence increased with both BMI and WHtR. Models with either of these two adiposity metrics had virtually identical C-statistics and NRIs for every region and sex, with C-statistics ranging from 0·72 to 0·81 and NRIs ranging from 0·34 to 0·57 in different region and sex combinations. When both BMI and WHtR were used, performance improved only slightly compared with using either adiposity measure alone. Interpretation: BMI can distinguish young and middle-aged adults with higher versus lower amounts of abdominal adiposity with moderate-to-high accuracy, and both BMI and WHtR distinguish people with or without hypertension. However, at the same BMI level, people in south Asia, Latin America and the Caribbean, and the region of central Asia, Middle East and north Africa, have higher WHtR than in the other regions. Funding: UK Medical Research Council and UK Research and Innovation (Innovate UK).

• Martinez-Gomez, David; Luo, Mengyun; Huang, Yu; Rodríguez-Artalejo, Fernando; Ekelund, Ulf & Sotos-Prieto, Mercedes [Show all 9 contributors for this article] (2024). Physical Activity and All-Cause Mortality by Age in 4 Multinational Megacohorts. JAMA Network Open. 7(11). doi: 10.1001/jamanetworkopen.2024.46802. Full text in Research Archive Show summary

  Importance: Physical activity (PA) guidelines recommend the same amount of PA through adulthood to live longer. Objective: To explore whether there is an age-dependent association between PA and all-cause mortality and to investigate the age-dependent associations between other modifiable health factors (high educational level, not smoking, not regularly consuming alcohol, healthy body weight, and living without hypertension and diabetes) and mortality. Design, Setting, and Participants: This cohort study used a pooled analysis of 4 population-based prospective cohorts (National Health Interview Survey, 1997-2018; UK Biobank, 2006-2010; China Kadoorie Biobank, 2004-2008; and Mei Jau, 1997-2016). Data were analyzed from June 2022 to September 2024. Exposures: Self-reported leisure-time PA. Main Outcomes and Measures: The primary outcome was deaths identified through follow-up linkage to national death registries. Analyses were performed for the total sample and by age groups (20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and ≥80 years). Cox proportional hazards regression models with stratification by study were used to calculate mortality hazard ratios and their 95% CIs for the pooled dataset and by age group. Results: A heterogeneous sample of 2 011 186 individuals (mean [SD] age, 49.1 [14.3] years; age range, 20-97 years; 1 105 581 women [55.0%]) were included. After a median (IQR) follow-up of 11.5 (9.3-13.5) years, 177 436 deaths occurred. The association between PA and mortality in the total sample showed a nonlinear dose-response pattern, but age modified this association (P for interaction

• Cillekens, Bart; Coenen, Pieter; Huysmans, Maaike A.; Holtermann, Andreas; Troiano, Richard P. & Mork, Paul Jarle [Show all 43 contributors for this article] (2024). Should workers be physically active after work? Associations of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels—An individual participant data meta-analysis. Journal of Sport and Health Science. ISSN 2095-2546. 14, p. 1–12. doi: 10.1016/j.jshs.2024.100987. Full text in Research Archive Show summary

  Background There is insufficient evidence to provide recommendations for leisure-time physical activity among workers across various occupational physical activity levels. This study aimed to assess the association of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels. Methods This study utilized individual participant data from 21 cohort studies, comprising both published and unpublished data. Eligibility criteria included individual-level data on leisure-time and occupational physical activity (categorized as sedentary, low, moderate, and high) along with data on all-cause and/or cardiovascular mortality. A 2-stage individual participant data meta-analysis was conducted, with separate analysis of each study using Cox proportional hazards models (Stage 1). These results were combined using random-effects models (Stage 2). Results Higher leisure-time physical activity levels were associated with lower all-cause and cardiovascular mortality risk across most occupational physical activity levels, for both males and females. Among males with sedentary work, high compared to sedentary leisure-time physical activity was associated with lower all-cause (hazard ratios (HR) = 0.77, 95% confidence interval (95%CI): 0.70–0.85) and cardiovascular mortality (HR = 0.76, 95%CI: 0.66–0.87) risk. Among males with high levels of occupational physical activity, high compared to sedentary leisure-time physical activity was associated with lower all-cause (HR = 0.84, 95%CI: 0.74–0.97) and cardiovascular mortality (HR = 0.79, 95%CI: 0.60–1.04) risk, while HRs for low and moderate levels of leisure-time physical activity ranged between 0.87 and 0.97 and were not statistically significant. Among females, most effects were similar but more imprecise, especially in the higher occupational physical activity levels. Conclusion Higher levels of leisure-time physical activity were generally associated with lower mortality risks. However, results for workers with moderate and high occupational physical activity levels, especially women, were more imprecise. Our findings suggests that workers may benefit from engaging in high levels of leisure-time physical activity, irrespective of their level of occupational physical activity.

• Wong, William W; Speakman, John R; Ainslie, Philip N; Anderson, Liam J; Arab, Leonore & Baddou, Issad [Show all 76 contributors for this article] (2024). Decline in Isotope Dilution Space Ratio Above Age 60 Could Affect Energy Estimates Using the Doubly Labeled Water Method. Journal of Nutrition. ISSN 0022-3166. 154(12), p. 3824–3831. doi: 10.1016/j.tjnut.2024.10.016. Full text in Research Archive Show summary

  Background Doubly labeled water is gold standard for measuring total energy expenditure (TEE). Measurements using the method are sensitive to the isotope dilution space ratio (DSR). Accuracy and precision of the method might be improved if we could identify factors influencing DSR. Objectives We evaluated the potential associations of age, sex, ethnicity, anthropometry, body composition, turnover rates of the isotopes, and geographical elevation with DSR. Methods We used univariate regression analysis to explore the relationships between the continuous variables and analysis of variance to test the relationships between the categorical variables with DSR. Subsequently, we used general linear model (GLM) and 1-way analysis of variance to evaluate the simultaneous associations of age, sex, ethnicity, fat-free mass (FFM) and fat mass (FM) on DSR. Results From 5678 measurements complied from studies around the world with diverse ethnicity and living at various elevations, the mean DSR was 1.0364 ± 0.0141. No meaningful physiologic effect of any of the continuous and categorical variable on DSR was detected. General linear model analysis revealed no effect of FFM and FM (P > 0.33) on DSR, but DSR decreased with age (P

• Ekelund, Ulf; Tarp, Jakob; Sanchez-Lastra, Miguel Adriano & Dalene, Knut Eirik (2024). Physical activity, sedentary time and health – a narrative review with new insights. Danish Medical Journal. 71(11). doi: 10.61409/A06240433. Full text in Research Archive Show summary

  Physical activity and sedentary time are associated with multiple health outcomes, and benefits also extend to those living with chronic conditions. These observations are primarily based on data from studies in which self-reported data assessed physical activity. Recent data where physical activity and sedentary time are measured with devices suggest that the dose-response association between device-measured physical activity and risk of incident diseases and mortality is greater and observed at lower levels of physical activity than indicated by self-reported data.

• Nordlund, David; Lav, Theodor; Jablonowski, Robert; Khoshnood, Ardavan; Ekelund, Ulf & Atar, Dan [Show all 9 contributors for this article] (2024). Contractility, ventriculoarterial coupling, and stroke work after acute myocardial infarction using CMR-derived pressure-volume loop data. Clinical Cardiology. ISSN 0160-9289. 47(1). doi: 10.1002/clc.24216. Full text in Research Archive Show summary

  Background Noninvasive left ventricular (LV) pressure-volume (PV) loops derived by cardiac magnetic resonance (CMR) have recently been shown to enable characterization of cardiac hemodynamics. Thus, such PV loops could potentially provide additional diagnostic information such as contractility, arterial elastance (Ea) and stroke work (SW) currently not available in clinical routine. This study sought to investigate to what extent PV-loop variables derived with a novel noninvasive method can provide incremental physiological information over cardiac dimensions and blood pressure in patients with acute myocardial infarction (MI). Methods A total of 100 patients with acute MI and 75 controls were included in the study. All patients underwent CMR 2−6 days after MI including assessment of myocardium at risk (MaR) and infarct size (IS). Noninvasive PV loops were generated from CMR derived LV volumes and brachial blood pressure measurements. The following variables were quantified: Maximal elastance (Emax) reflecting contractility, Ea, ventriculoarterial coupling (Ea/Emax), SW, potential energy, external power, energy per ejected volume, and efficiency. Results All PV-loop variables were significantly different in MI patients compared to healthy volunteers, including contractility (Emax: 1.34 ± 0.48 versus 1.50 ± 0.41 mmHg/mL, p = .024), ventriculoarterial coupling (Ea/Emax: 1.27 ± 0.61 versus 0.73 ± 0.17, p < .001) and SW (0.96 ± 0.32 versus 1.38 ± 0.32 J, p < .001). These variables correlated to both MaR and IS (Emax: r2 = 0.25 and r2 = 0.29; Ea/Emax: r2 = 0.36 and r2 = 0.41; SW: r2 = 0.21 and r2 = 0.25). Conclusions Noninvasive PV-loops provide physiological information beyond conventional diagnostic variables, such as ejection fraction, early after MI, including measures of contractility, ventriculoarterial coupling, and SW.

• Coenen, Pieter; Huysmans, Maaike A.; Holtermann, Andreas; Troiano, Richard P.; Mork, Paul Jarle & Krokstad, Steinar [Show all 46 contributors for this article] (2024). Associations of occupational and leisure-time physical activity with all-cause mortality: an individual participant data meta-analysis. British Journal of Sports Medicine. ISSN 0306-3674. 58(4), p. 1527–1538. doi: 10.1136/bjsports-2024-108117. Full text in Research Archive Show summary

  Objective: Health effects of different physical activity domains (ie, during leisure time, work and transport) are generally considered positive. Using Active Worker consortium data, we assessed independent associations of occupational and leisure-time physical activity (OPA and LTPA) with all-cause mortality. Design: Two-stage individual participant data meta-analysis. Data source: Published and unpublished cohort study data. Eligibility criteria: Working participants aged 18–65 years. Methods: After data harmonisation, we assessed associations of OPA and LTPA with all-cause mortality. In stage 1, we analysed data from each study separately using Cox survival regression, and in stage 2, we pooled individual study findings with random-effects modelling. Results: In 22 studies with up to 590 497 participants from 11 countries, during a mean follow-up of 23.1 (SD: 6.8) years, 99 743 (16%) participants died. Adjusted for LTPA, body mass index, age, smoking and education level, summary (ie, stage 2) hazard ration (HRs) and 95% confidence interval (95% CI) for low, moderate and high OPA among men (n=2 96 134) were 1.01 (0.99 to 1.03), 1.05 (1.01 to 1.10) and 1.12 (1.03 to 1.23), respectively. For women (n=2 94 364), HRs (95% CI) were 0.98 (0.92 to 1.04), 0.96 (0.92 to 1.00) and 0.97 (0.86 to 1.10), respectively. In contrast, higher levels of LTPA were inversely associated with mortality for both genders. For example, for women HR for low, moderate and high compared with sedentary LTPA were 0.85 (0.81 to 0.89), 0.78 (0.74 to 0.81) and 0.75 (0.65 to 0.88), respectively. Effects were attenuated when adjusting for income (although data on income were available from only 9 and 6 studies, for men and women, respectively). Conclusion: Our findings indicate that OPA may not result in the same beneficial health effects as LTPA.

• Tarp, Jakob; Dalene, Knut Eirik; Fagerland, Morten; Steene-Johannessen, Jostein; Hansen, Bjørge Hermann & Anderssen, Sigmund Alfred [Show all 23 contributors for this article] (2024). Physical Activity Volume, Intensity, and Mortality: Harmonized Meta-Analysis of Prospective Cohort Studies. American Journal of Preventive Medicine. ISSN 0749-3797. 67(6), p. 887–896. doi: 10.1016/j.amepre.2024.07.022. Full text in Research Archive Show summary

  Introduction: It is unclear whether moderate-to-vigorous physical activity (MVPA) is associated with a lower mortality risk, over and above its contribution to total physical activity volume. Methods: 46,682 adults (mean age: 64 years) were included in a meta-analysis of nine prospective cohort studies. Each cohort generated tertiles of accelerometry-measured physical activity volume and volume-adjusted MVPA. Hazard ratios (HR, with 95% confidence intervals) for mortality were estimated separately and in joint models combining volume and MVPA. Data was collected between 2001 and 2019 and analyzed in 2023. Results: During a mean follow-up of 9 years, 4,666 deaths were recorded. Higher physical activity volume, and a greater contribution from volume-adjusted MVPA, were each associated with lower mortality hazard in multivariable-adjusted models. Compared to the least active tertile, higher physical activity volume was associated with a lower mortality (HRs: 0.62; 0.58, 0.67 and 0.50; 0.42, 0.60 for ascending tertiles). Similarly, a greater contribution from MVPA was associated with a lower mortality (HRs: 0.94; 0.85, 1.04 and 0.88; 0.79, 0.98). In joint analysis, a lower mortality from higher volume-adjusted MVPA was only observed for the middle tertile of physical activity volume. Conclusions: The total volume of physical activity was associated with a lower risk of mortality to a greater extent than the contribution of MVPA to physical activity volume. Integrating any intensity of physical activity into daily life may lower mortality risk in middle-aged and older adults, with a small added benefit if the same amount of activity is performed with a higher intensity.

• Ostojic, Sergej; Phelps, Nowell H.; Singleton, Rosie K.; Zhou, Bin; Heap, Rachel & Mishra, Anu [Show all 54 contributors for this article] (2024). Worldwide trends in the underweight and obesity from 1990 to 2022: a pooled analysis of 3,633 population-representative studies with 222 million school-aged children, adolescents, and adults. The Lancet. ISSN 0140-6736. 403(10431), p. 1027–1050. doi: 10.1016/S0140-6736(23)02750-2. Full text in Research Archive Show summary

  Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.

• Husøy, Anders; Kolle, Elin; Steene-Johannessen, Jostein; Dalene, Knut Eirik; Andersen, Lars Bo & Ekelund, Ulf [Show all 7 contributors for this article] (2024). Longitudinal changes in device-measured physical activity from childhood to young adulthood: the PANCS follow-up study. International Journal of Behavioral Nutrition and Physical Activity. 21(1). doi: 10.1186/s12966-024-01578-7. Full text in Research Archive Show summary

  Background There is a lack of longitudinal studies examining changes in device-measured physical activity and sedentary time from childhood to young adulthood. We aimed to assess changes in device-measured physical activity and sedentary time from childhood, through adolescence, into young adulthood in a Norwegian sample of ostensibly healthy men and women. Methods A longitudinal cohort of 731 Norwegian boys and girls (49% girls) participated at age 9 years (2005–2006) and 15 years (2011–2012), and 258 of these participated again at age 24 years (2019–2021; including the COVID-19 pandemic period). Physical activity and sedentary time were measured using ActiGraph accelerometers. Linear mixed models were used to analyse changes in physical activity and sedentary time and whether low levels of childhood physical activity track, i.e., persist into young adulthood (nchange=721; ntracking=640). Results The most prominent change occurred between the ages of 9 to 15 years, with an increase in sedentary time (150 min/day) and less time spent in light (125 min/day), moderate (16 min/day), and vigorous physical activity (8 min/day). Only smaller changes were observed between the ages of 15 and 24 years. Changes in moderate-to-vigorous physical activity from childhood to young adulthood differed between subgroups of sex, tertiles of body mass index at baseline and tertiles of peak oxygen uptake at baseline. While the tracking models indicated low absolute stability of physical activity from childhood to young adulthood, children in the lowest quartiles of moderate-to-vigorous (OR:1.88; 95%CI: 1.23, 2.86) and total physical activity (OR: 1.87; 95%CI: 1.21, 2.87) at age 9 years were almost 90% more likely to be in these quartiles at age 24 years compared to those belonging to the upper three quartiles at baseline. Conclusions We found a substantial reduction in physical activity and increase in time spent sedentary between age 9 and 15 years. Contrary to previous studies, using mainly self-reported physical activity, little change was observed between adolescence and young adulthood. The least active children were more likely to remain the least active adults and could be targeted for early intervention.

• Zou, Liye; Herold, Fabian; Cheval, Boris; Wheeler, Michael J.; Pindus, Dominika M. & Erickson, Kirk I. [Show all 16 contributors for this article] (2024). Sedentary behavior and lifespan brain health. Trends in Cognitive Sciences. ISSN 1364-6613. 28(4), p. 369–382. doi: 10.1016/j.tics.2024.02.003. Full text in Research Archive
• Jalanko, Petri; Bond, Bert; Laukkanen, Jari A.; Brage, Søren Karl; Ekelund, Ulf & Laitinen, Tomi [Show all 10 contributors for this article] (2024). Association between arterial health and cognition in adolescents: The PANIC study. Physiological Reports. 12(9). doi: 10.14814/phy2.16024. Full text in Research Archive Show summary

  We investigated the associations of the measures of arterial health with cognition in adolescents and whether physical activity (PA) or sedentary time (ST) confounds these associations. One hundred sixteen adolescents (71 boys) aged 15.9 ± 0.4 participated in the study. PA and ST were assessed using a combined accelerometer/heart rate monitor. Overall cognition was computed from the results of psychomotor function, attention, working memory, and paired-associate learning tests. Pulse wave velocity was measured by impedance cardiography, carotid intima-media thickness, and carotid artery distensibility by carotid ultrasonography. Systolic and diastolic blood pressure (SBP and DBP) were measured using an aneroid sphygmomanometer. SBP was inversely associated with overall cognition (standardized regression coefficient [β] = −0.216, 95% confidence interval (CI) −0.406 to −0.027, p = 0.025). Pulse wave velocity (β = −0.199, 95% CI −0.382 to −0.017, p = 0.033) was inversely associated with working memory task accuracy. SBP was directly associated with reaction time in the attention (β = 0.256, 95% CI 0.069 to 0.443, p = 0.008) and errors in the paired-associate learning tasks (β = 0.308, 95% CI 0.126 to 0.489, p = 0.001). Blood pressure was inversely associated with overall cognition. PA or ST did not confound the associations. Results suggest that preventing high blood pressure is important for promoting cognition in adolescents.

• Alves, Charles Phillipe de Lucena; Leão, Otávio Amaral de Andrade; Delpino, Felipe Mendes; Mielke, Gregore Iven; Ekelund, Ulf & Costa, Eduardo Caldas [Show all 7 contributors for this article] (2024). Independent, Stratified, and Joint Associations of Sedentary Time and Physical Activity With Cardiovascular Disease: A Systematic Review. Journal of Physical Activity and Health. ISSN 1543-3080. 21(10), p. 980–989. doi: 10.1123/jpah.2024-0019. Full text in Research Archive Show summary

  Background: Recent statistics highlight cardiovascular diseases (CVD) as a major global cause of death. This review examines the methodological approaches and the main results of independent, stratified, and joint association of sedentary time (ST) and physical activity (PA) on CVD outcomes. Methods: We searched PubMed, Embase, Web of Science, and Scopus for prospective cohorts that examined the independent, stratified, or joint associations of ST and PA with CVD outcomes. Independent associations were defined as analyses mutually adjusted for PA and ST. Stratified associations were considered when there was a reference group in each stratum of PA or ST, and joint associations were defined by a single reference group for all other combined categories of ST and PA levels. Results: Of 45 articles, 69% explored independent association of ST or PA on CVD outcomes, while 31% using a stratified/joint approach. Most studies used self-reports for ST and PA and focused on CVD mortality. Mutually adjusted analyses identified ST positively and PA inversely associated to CVD outcomes. Stratified studies showed higher ST’s pronounced impact on CVD for lower PA levels. High PA mitigated but did not eliminate ST’s negative impact. Joint analyses revealed highest CVD risk in those with both high ST and low PA, and elevated risk in various intermediate combinations. Conclusions: Employing independent, stratified, and joint association approaches can yield distinct and complementary public health messages aimed at promoting cardiovascular health. Recommendations should aim to not only to encourage boosting PA levels, but also, concurrently decrease ST.

• Rezende, Leandro F. M.; Ahmadi, Matthew; Ferrari, Gerson; Cruz, Borja del Pozo; Lee, I-Min & Ekelund, Ulf [Show all 7 contributors for this article] (2024). Device-measured sedentary time and intensity-specific physical activity in relation to all-cause and cardiovascular disease mortality: the UK Biobank cohort study. International Journal of Behavioral Nutrition and Physical Activity. 21(1). doi: 10.1186/s12966-024-01615-5. Full text in Research Archive Show summary

  Background and aims: Understanding the amounts of intensity-specific movement needed to attenuate the association between sedentary time and mortality may help to inform personalized prescription and behavioral counselling. Herein, we examined the joint associations of sedentary time and intensity-specific physical activity with all-cause and cardiovascular disease (CVD) mortality. Methods: Prospective cohort study including 73,729 adults from the UK Biobank who wore an Axivity AX3 accelerometer on their dominant wrist for at least 3 days, being one a weekend day, between June 2013 and December 2015. We considered the median tertile values of sedentary time and physical activity in each intensity band to determine the amount of physical activity needed to attenuate the association between sedentary time and mortality. Results: During a median of 6.9 years of follow-up (628,807 person-years), we documented 1521 deaths, including 388 from CVD. Physical activity of any intensity attenuated the detrimental association of sedentary time with mortality. Overall, at least a median of 6 min/day of vigorous physical activity, 30 min/day of MVPA, 64 min/day of moderate physical activity, or 163 min/day of light physical activity (mutually-adjusted for other intensities) attenuated the association between sedentary time and mortality. High sedentary time was associated with higher risk of CVD mortality only among participants with low MVPA (HR 1.96; 95% CI 1.23 to 3.14). Conclusions: Different amounts of each physical activity intensity may attenuate the association between high sedentary time and mortality.

• Ahmadi, Matthew N.; Blodgett, Joanna M.; Atkin, Andrew J; Chan, Hsiu-Wen; Cruz, Borja del Pozo & Suorsa, Kristin [Show all 24 contributors for this article] (2024). Relationship of device-measured physical activity type and posture with cardiometabolic health markers: pooled dose–response associations from the Prospective Physical Activity, Sitting and Sleep Consortium. Diabetologia. ISSN 0012-186X. 67(6), p. 1051–1065. doi: 10.1007/s00125-024-06090-y. Full text in Research Archive Show summary

  Aims/hypothesis: The aim of this study was to examine the dose–response associations of device-measured physical activity types and postures (sitting and standing time) with cardiometabolic health. Methods: We conducted an individual participant harmonised meta-analysis of 12,095 adults (mean ± SD age 54.5±9.6 years; female participants 54.8%) from six cohorts with thigh-worn accelerometry data from the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. Associations of daily walking, stair climbing, running, standing and sitting time with a composite cardiometabolic health score (based on standardised z scores) and individual cardiometabolic markers (BMI, waist circumference, triglycerides, HDL-cholesterol, HbA1c and total cholesterol) were examined cross-sectionally using generalised linear modelling and cubic splines. Results: We observed more favourable composite cardiometabolic health (i.e. z score [95% CI] −0.14 [−0.25, −0.02]) and 5 min/day stair climbing (−0.14 [−0.24, −0.03]). We observed an equivalent magnitude of association at 2.6 h/day standing. Any amount of running was associated with better composite cardiometabolic health. We did not observe an upper limit to the magnitude of the dose–response associations for any activity type or standing. There was an inverse dose–response association between sitting time and composite cardiometabolic health that became markedly less favourable when daily durations exceeded 12.1 h/day. Associations for sitting time were no longer significant after excluding participants with prevalent CVD or medication use. The dose–response pattern was generally consistent between activity and posture types and individual cardiometabolic health markers. Conclusions/interpretation: In this first activity type-specific analysis of device-based physical activity, ~64 min/day of walking and ~5.0 min/day of stair climbing were associated with a favourable cardiometabolic risk profile. The deleterious associations of sitting time were fully attenuated after exclusion of participants with prevalent CVD and medication use. Our findings on cardiometabolic health and durations of different activities of daily living and posture may guide future interventions involving lifestyle modification.

• Wendt, Andrea; Bielemann, Renata Moraes; Wehrmeister, Fernando C.; Ricardo, Luiza I.C.; Müller, Werner de Andrade & Machado, Adriana Kramer Fiala [Show all 12 contributors for this article] (2024). Is rest-activity rhythm prospectively associated with all-cause mortality in older people regardless of sleep and physical activity level? The ‘Como Vai?’ Cohort study. PLOS ONE. 19(2). doi: 10.1371/journal.pone.0298031. Full text in Research Archive Show summary

  Objective: This study aims to test the association of rest-activity rhythm (intradaily variability and interdaily stability) with all-cause mortality in an older adult cohort in Brazil. It also assesses whether the amount of time spent at each intensity level (i.e., physical activity and nocturnal sleep) interferes with this association. Methods: This cohort study started in 2014 with older adults (≥60 years). We investigated deaths from all causes that occurred until April 2017. Rest-activity rhythm variables were obtained using accelerometry at baseline. Intradaily variability indicates higher rhythm fragmentation, while interdaily stability indicates higher rhythm stability. Cox proportional-hazard models were used to test the associations controlling for confounders. Results: Among the 1451 older adults interviewed in 2014, 965 presented valid accelerometry data. During the follow-up period, 80 individuals died. After adjusting the analysis for sociodemographic, smoking, morbidity score, and number of medicines, an increase of one standard deviation in interdaily stability decreased 26% the risk of death. The adjustment for total sleep time and inactivity did not change this association. On the other hand, the association was no longer significant after adjusting for overall physical activity and moderate to vigorous physical activity. Conclusion: Rest-activity rhythm pattern was not associated with mortality when physical activity was considered, possibly because this pattern could be driven by regular exercise. Promoting physical activity remains a relevant strategy to improve population health.

• Blodgett, Joanna M.; Ahmadi, Matthew N.; Atkin, Andrew J.; Chastin, Sebastian; Chan, Hsiu-Wen & Suorsa, Kristin [Show all 29 contributors for this article] (2023). Device-measured physical activity and cardiometabolic health: the Prospective Physical Activity, Sitting, and Sleep (ProPASS) consortium. European Heart Journal. ISSN 0195-668X. 45(6), p. 458–471. doi: 10.1093/eurheartj/ehad717. Full text in Research Archive Show summary

  Background and Aims: Physical inactivity, sedentary behaviour (SB), and inadequate sleep are key behavioural risk factors of cardiometabolic diseases. Each behaviour is mainly considered in isolation, despite clear behavioural and biological interdependencies. The aim of this study was to investigate associations of five-part movement compositions with adiposity and cardiometabolic biomarkers. Methods: Cross-sectional data from six studies (n = 15 253 participants; five countries) from the Prospective Physical Activity, Sitting and Sleep consortium were analysed. Device-measured time spent in sleep, SB, standing, light-intensity physical activity (LIPA), and moderate-vigorous physical activity (MVPA) made up the composition. Outcomes included body mass index (BMI), waist circumference, HDL cholesterol, total:HDL cholesterol ratio, triglycerides, and glycated haemoglobin (HbA1c). Compositional linear regression examined associations between compositions and outcomes, including modelling time reallocation between behaviours. Results: The average daily composition of the sample (age: 53.7 ± 9.7 years; 54.7% female) was 7.7 h sleeping, 10.4 h sedentary, 3.1 h standing, 1.5 h LIPA, and 1.3 h MVPA. A greater MVPA proportion and smaller SB proportion were associated with better outcomes. Reallocating time from SB, standing, LIPA, or sleep into MVPA resulted in better scores across all outcomes. For example, replacing 30 min of SB, sleep, standing, or LIPA with MVPA was associated with −0.63 (95% confidence interval −0.48, −0.79), −0.43 (−0.25, −0.59), −0.40 (−0.25, −0.56), and −0.15 (0.05, −0.34) kg/m2 lower BMI, respectively. Greater relative standing time was beneficial, whereas sleep had a detrimental association when replacing LIPA/MVPA and positive association when replacing SB. The minimal displacement of any behaviour into MVPA for improved cardiometabolic health ranged from 3.8 (HbA1c) to 12.7 (triglycerides) min/day. Conclusions: Compositional data analyses revealed a distinct hierarchy of behaviours. Moderate-vigorous physical activity demonstrated the strongest, most time-efficient protective associations with cardiometabolic outcomes. Theoretical benefits from reallocating SB into sleep, standing, or LIPA required substantial changes in daily activity.

• Oliveira, Arão Belitardo de; Katzmarzyk, Peter T.; Dantas, Wagner Silva; Benseñor, Isabela Judith Martins; Goulart, Alessandra de Carvalho & Ekelund, Ulf (2023). Profile of leisure-time physical activity and sedentary behavior in adults in Brazil: a nationwide survey, 2019. Epidemiologia e Serviços de Saúde. ISSN 1679-4974. 32(2). doi: 10.1590/S2237-96222023000200016. Full text in Research Archive Show summary

  Objectives: to estimate the prevalence of leisure-time physical activity and sedentary behavior in adults in Brazil. Methods: this was a cross-sectional, population-based study carried out in a sample of 88,531 Brazilians, using data from the 2019 National Health Survey; leisure-time physical activity (overall and aerobic exercise) was measured according to the World Health Organization guidelines; the weighted prevalence and respective 95% confidence intervals (95%CI) of physical activity, physical inactivity and sedentary behavior were estimated. Results: according to the selected sample, 26.4% (95%CI 25.9;27.1) of Brazilian adults were physically active, 14.0% (95%CI 13.5;14.4) were insufficiently physically active and 59.5% (95%CI 58.8;60.2) were physically inactive; sedentary behavior ≥ 6 hours was reported by 30.1% (95%CI 29.5;30.8) of the population; only 8.6% (95%CI 8.2;8.9) met the recommendations for muscle-strengthening activities. Conclusion: most Brazilian adults were physically inactive and did not meet international recommendations for leisure-time physical activity and reduction in sedentary behavior.

• Speakman, John R.; Jong, Jasper M A de; Sinha, Srishti; Westerterp, Klaas R.; Yamada, Yosuke & Sagayama, Hiroyuki [Show all 80 contributors for this article] (2023). Total daily energy expenditure has declined over the past three decades due to declining basal expenditure, not reduced activity expenditure. Nature Metabolism. 5(4), p. 579–588. doi: 10.1038/s42255-023-00782-2. Full text in Research Archive Show summary

  Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.

• Dalene, Knut Eirik & Ekelund, Ulf (2023). Assessment of physical activity behaviours: methods, levels, and time trends. In Armstrong, Neil & Mechelen, Willem van (Ed.), Oxford Textbook of Children’s Sport and Exercise Medicine. Fourth Edition. Oxford University Press. ISSN 9780191926556. Full text in Research Archive
• Zarbo, Cristina; Rota, Matteo; Calza, Stefano; Crouter, Scott E; Ekelund, Ulf & Barlati, Stefano [Show all 17 contributors for this article] (2023). Ecological monitoring of physical activity, emotions and daily life activities in schizophrenia: The DiAPAson study. BMJ Mental Health. 26(1), p. 1–8. doi: 10.1136/bmjment-2023-300836. Full text in Research Archive Show summary

  Background: Schizophrenia spectrum disorders (SSD) compromise psychosocial functioning, including daily time use, emotional expression and physical activity (PA). Objective: We performed a cohort study aimed at investigating: (1) the differences in PA, daily activities and emotions between patients with SSD and healthy controls (HC); (2) the strength of the association between these variables and clinical features among patients with SSD. Methods: Ninety-nine patients with SSD (53 residential patients, 46 outpatients) and 111 matched HC were assessed for several clinical variables, and levels of functioning by means of standardised clinical measures. Self-reported daily activities and emotions were assessed with a smartphone application for ecological momentary assessment (EMA), and PA levels were assessed with a wearable accelerometer for 7 consecutive days. Findings: Patients with SSD, especially those living in residential facilities, spent more time being sedentary, and self-reported more sedentary and self-care activities, experiencing higher levels of negative emotions compared with HC. Moreover, higher functioning levels among patients were associated with more time spent in moderate-to-vigorous activity. Conclusions: Sedentary behaviour and negative emotions are particularly critical among patients with SSD and are associated with more impaired clinical outcomes. Clinical implications: Mobile-EMA and wearable sensors are useful for monitoring the daily life of patients with SSD and the level of PA. This population needs to be targeted with specific rehabilitative programmes aimed at improving their commitment to structured daily activities.

• Leão, Otávio Amaral de Andrade; Flores, Thaynã Ramos; Barratt, Jaime; Bertoldi, Andréa Dâmaso; Domingues, Marlos Rodrigues & Cairney, John [Show all 10 contributors for this article] (2023). Bi-directional associations between physical activity and growth indicators of pre-school aged children. Journal of Sports Sciences. ISSN 0264-0414. 41(8), p. 766–773. doi: 10.1080/02640414.2023.2240167. Full text in Research Archive Show summary

  Physical activity for young children provides a wealth of benefits for health and development. However, little is known about the inter-relationship of physical activity and growth indicators. The aim of this study was to test the bi-directional associations of physical activity and growth indicators in children under five years of age. This prospective study included 1,575 children with data on physical activity and growth indicators at ages 12, 24 and 48 months. Accelerometers were used to measure physical activity. Z-scores for length/height-for-age, weight-for-length/height, weight-for-age and body mass index (BMI)-for-age were calculated. Bi-directional associations between physical activity and growth indicators were evaluated using cross-lagged panels based on Generalized Estimating Equations and cross-lagged structural equation models. Physical activity was consistently associated with lower weight-related growth indicators: BMI-for-age: β=-0.12; Weight-for-age: β=-0.11; Weight-for-length/height: β=-0.12. Higher BMI-for-age indicated lower physical activity (β=-0.06). When the exposure was lagged, the association of physical activity on weight-related growth indicators remained, but weight-related growth indicators showed a negative association on physical activity. A bi-directional association between physical activity and weight-related growth indicators was observed. The magnitude of associations were stronger when physical activity was modelled as exposure. These results reinforce the importance of physical activity since early years.

• Halsey, Lewis G.; Careau, Vincent; Ainslie, Philip N.; Alemán-Mateo, Heliodoro; Andersen, Lene Frost & Anderson, Liam J. [Show all 110 contributors for this article] (2023). Greater male variability in daily energy expenditure develops through puberty. Biology Letters. ISSN 1744-9561. 19(9). doi: 10.1098/rsbl.2023.0152. Full text in Research Archive Show summary

  There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decrease in the degree of GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages.

• Mielke, Gregore Iven; Almeida Mendes, Márcio de; Ekelund, Ulf; Rowlands, Alex V.; Reichert, Felipe Fossati & Crochemore-Silva, Inacio (2023). Absolute intensity thresholds for tri-axial wrist and waist accelerometer-measured movement behaviors in adults. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 33(9), p. 1752–1764. doi: 10.1111/sms.14416. Full text in Research Archive Show summary

  Aim: This study was aimed to: (1) compare raw triaxial acceleration data from GENEActiv (GA) and ActiGraph GT3X+ (AG) placed on the non-dominant wrist; (2) compare AG placed on the non-dominant and dominant wrist, and waist; (3) derive brand- and placement-specific absolute intensity thresholds for inactive and sedentary time, and physical activity intensity in adults. Methods: Eighty-six adults (44 men; 34.6 ± 10.8 years) performed nine activities while simultaneously wearing GA and AG on wrist and waist. Acceleration (in gravitational equivalent units; mg) was compared with oxygen uptake (measured with indirect calorimetry). Results: Increases in acceleration mirrored increases in intensity of activities, regardless of device brand and placement. Differences in acceleration between GA and AG worn at the non-dominant wrist were small but tended to be high at lower intensity activities. Thresholds for differentiating inactivity (<1.5 MET) from activity (≥1.5 MET) ranged from 25 mg (AG non-dominant wrist; sensitivity 93%, specificity 95%) to 40 mg (AG waist; sensitivity 78%, specificity 100%). For moderate intensity (≥3 METs), thresholds ranged from 65 mg (AG waist; sensitivity 96%, specificity 94%) to 92 mg (GA non-dominant; sensitivity 93%, specificity 98%); vigorous intensity (≥6 METs) thresholds ranged from 190 mg (AG waist; sensitivity 82%, specificity 92%) to 283 mg (GA non-dominant; sensitivity 93%, specificity 98%). Conclusion: Raw triaxial acceleration outputs from two widely used accelerometer brands may have limited comparability in low intensity activities. Thresholds derived in this study can be utilized in adults to reasonably classify movement behaviors into categories of intensity.

• Tarp, Jakob; Luo, Mengyun; Sanchez-Lastra, Miguel Adriano; Dalene, Knut Eirik; Cruz, Borja Del Pozo & Ried-Larsen, Mathias [Show all 9 contributors for this article] (2023). Leisure-time physical activity and all-cause mortality and cardiovascular disease in adults with type 2 diabetes: Cross-country comparison of cohort studies. Journal of Sport and Health Science. ISSN 2095-2546. 13(2), p. 212–221. doi: 10.1016/j.jshs.2023.10.004. Full text in Research Archive Show summary

  Background: This study aimed to quantify the dose–response association and the minimal effective dose of leisure-time physical activity (PA) to prevent mortality and cardiovascular disease in adults with type 2 diabetes. Methods: Cross-country comparison of 2 prospective cohort studies including 14,913 and 17,457 population-based adults with type 2 diabetes from the UK and China. Baseline leisure-time PA was self-reported and categorized by metabolic equivalent hours per week (MET-h/week) according to World Health Organization recommendations: none, below recommendation (>0–7.49 MET-h/week); at recommended level (7.5–14.9 MET-h/week); above recommendation (≥15 MET-h/week). Mortality and cardiovascular disease data were obtained from national registries. Results: During a median follow-up of 12.4 and 9.7 years, higher levels of leisure-time PA were inversely associated with all-cause (1571 and 2351 events) and cardiovascular mortality (392 and 1060 events) in both cohorts, mostly consistent with a linear dose–response relationship. PA below, at, and above recommendations, compared with no activity, yielded all-cause mortality hazard ratios of 0.94 (95% confidence interval (95%CI): 0.79–1.12), 0.90 (95%CI: 0.74–1.10), and 0.85 (95%CI: 0.70–1.02) in British adults and 0.87 (95%CI: 0.68–1.10), 0.88 (95%CI: 0.74–1.03), and 0.77 (95%CI: 0.70–0.85) in Chinese adults. Associations with cardiovascular mortality were more pronounced in British adults (0.80 (95%CI: 0.58–1.11), 0.75 (95%CI: 0.52–1.09), and 0.69 (95%CI: 0.48–0.97)) but less pronounced in Chinese adults (1.06 (95%CI: 0.76–1.47), 1.01 (95%CI: 0.80–1.28), and 0.79 (95%CI: 0.69–0.92)). PA at recommended levels was not associated with lower rates of major adverse cardiovascular events (2345 and 4458 events). Conclusion: Leisure-time PA at the recommended levels was not convincingly associated with lower mortality and had no association with risk of major adverse cardiovascular events in British or Chinese adults with type 2 diabetes. Leisure-time PA above current recommendations may be needed to prevent cardiovascular disease and premature mortality in adults with type 2 diabetes.

• Mishra, Anu; Zhou, Bin; Rodriguez-Martinez, Andrea; Bixby, Honor; Singleton, Rosie K. & Carrillo-Larco, Rodrigo M. [Show all 1,626 contributors for this article] (2023). Diminishing benefits of urban living for children and adolescents’ growth and development. Nature. ISSN 0028-0836. 615(7954), p. 874–883. doi: 10.1038/s41586-023-05772-8. Full text in Research Archive Show summary

  Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1,2,3,4,5,6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.

• Sagelv, Edvard Hamnvik; Dalene, Knut Eirik; Eggen, Anne Elise; Ekelund, Ulf; Fimland, Marius Steiro & Heitmann, Kim Arne [Show all 11 contributors for this article] (2023). Occupational physical activity and risk of mortality in women and men: the Tromsø Study 1986–2021. British Journal of Sports Medicine. ISSN 0306-3674. 58(2), p. 81–88. doi: 10.1136/bjsports-2023-107282. Full text in Research Archive Show summary

  Objective Associations between occupational physical activity (OPA) and mortality risks are inconclusive. We aimed to examine associations between (1) OPA separately and (2) jointly with leisure time physical activity (LTPA), and risk of all-cause, cardiovascular disease (CVD) and cancer mortality, over four decades with updated exposure and covariates every 6–8 years. Methods Adults aged 20–65 years from the Tromsø Study surveys Tromsø3-Tromsø7 (1986–2016) were included. We categorised OPA as low (sedentary), moderate (walking work), high (walking+lifting work) or very high (heavy manual labour) and LTPA as inactive, moderate and vigorous. We used Cox/Fine and Gray regressions to examine associations, adjusted for age, body mass index, smoking, education, diet, alcohol and LTPA (aim 1 only). Results Of 29 605 participants with 44 140 total observations, 4131 (14.0%) died, 1057 (25.6%) from CVD and 1660 (40.4%) from cancer, during follow-up (median: 29.1 years, 25th–75th: 16.5.1–35.3). In men, compared with low OPA, high OPA was associated with lower all-cause (HR 0.83, 95% CI 0.74 to 0.92) and CVD (subdistributed HR (SHR) 0.68, 95% CI 0.54 to 0.84) but not cancer mortality (SHR 0.99, 95% CI 0.84 to 1.19), while no association was observed for moderate or very high OPA. In joint analyses using inactive LTPA and low OPA as reference, vigorous LTPA was associated with lower all-cause mortality combined with low (HR 0.75, 95% CI 0.64 to 0.89), high (HR 0.67, 95% CI 0.54 to 0.82) and very high OPA (HR 0.74, 95% CI 0.58 to 0.94), but not with moderate OPA. In women, there were no associations between OPA, or combined OPA and LTPA, with mortality. Conclusion High OPA, but not moderate and very high OPA, was associated with lower all-cause and CVD mortality risk in men but not in women. Vigorous LTPA was associated with lower mortality risk in men with low, high and very high OPA, but not moderate OPA.

• Sanchez-Lastra, Miguel Adriano; Ding, Ding; Dalene, Knut Eirik; Cruz, Borja del Pozo; Ekelund, Ulf & Tarp, Jakob (2023). Body composition and mortality from middle to old age: a prospective cohort study from the UK Biobank. International Journal of Obesity. ISSN 0307-0565. 47(8), p. 709–716. doi: 10.1038/s41366-023-01314-4. Full text in Research Archive Show summary

  Background: How the association between adiposity and the risk of death changes with age, and which is the optimal level of adiposity to reduce mortality in older ages, is still not completely understood. We aimed to ascertain the age-specific risks of mortality associated with different measures of adiposity. Methods: This was a prospective UK Biobank cohort study. Participants were categorized based on five different adiposity and body composition metrics. We explored the age-varying associations between body composition indices and all-cause mortality from 45 to 85 years of age at follow-up using hazard ratios (HR) from flexible parametric survival models with multivariable adjustment and age as timescale. Participants were followed from baseline (2006–2010) through 31 March 2020. Results: We included 369,752 participants (mean baseline age = 56.3 ± 8.1 years; range 38.9–73.7 years; 54.1% women) and 10,660 deaths during a median follow-up of 11.4 years. Associations between body mass index and mortality were similar when using the fat mass index in magnitude and shape. Compared to participants with normal weight, overweight was not associated with the risk of death regardless of age and the adiposity measure used. Participants with obesity class I showed an HR of 1.20 (95% confidence interval [CI]: 1.08, 1.33) and 1.14 (95%CI: 0.98, 1.30) at ages 60 and 80, respectively, and participants with obesity class II an HR about 1.55 across all age. More attenuated associations with higher age were found in individuals with the highest obesity using the fat mass index. Very high lean mass was associated with an increased risk of mortality in those aged 55–75 years (HR about 1.20 across all ages). Conclusion: Obesity should be prevented at any age. Attenuated associations with older age were observed only among the individuals with the highest obesity, but the risk remained higher compared to normal-weight participants. Lean mass did not reduce mortality risk at any age.

• Kristensen, Frederik Pagh Bredahl; Sanchez-Lastra, Miguel Adriano; Dalene, Knut Eirik; Cruz, Borja Del Pozo; Ried-Larsen, Mathias & Thomsen, Reimar Wernich [Show all 9 contributors for this article] (2023). Leisure-Time Physical Activity and Risk of Microvascular Complications in Individuals With Type 2 Diabetes: A UK Biobank Study. Diabetes Care. ISSN 0149-5992. 46(10), p. 1816–1824. doi: 10.2337/dc23-0937. Full text in Research Archive Show summary

  OBJECTIVE: The aim of this study was to determine dose-response associations, including the minimal effective level, between leisure-time physical activity and risk of incident neuropathy, nephropathy, and retinopathy. RESEARCH DESIGN AND METHODS: This cohort study included 18,092 individuals with type 2 diabetes from the UK Biobank. Self-reported leisure-time physical activity was converted into MET-hours per week. Participants were categorized into no physical activity (0 MET-h/week), below recommendations (0–7.49 MET-h/week), at recommendations (7.5–14.9 MET-h/week), and above recommendations (≥15 MET-h/week). Microvascular complications were identified from hospital inpatient records using diagnosis codes. We used Cox proportional hazards regression analysis to calculate adjusted hazard ratios (aHRs) and restricted cubic splines to identify the minimal effective level of physical activity. RESULTS: During a median follow-up of 12.1 years, 672 individuals (3.7%) were diagnosed with neuropathy, 1,839 (10.2%) with nephropathy, and 2,099 (11.7%) with retinopathy. Any level of physical activity was associated with a lower risk of neuropathy and nephropathy but not retinopathy. Compared with those reporting no physical activity, the aHR of neuropathy was 0.71 (95% CI 0.53, 0.90) below recommendations, 0.73 (0.56, 0.96) at recommendations, and 0.67 (0.52, 0.87) above recommendations. Corresponding aHRs for nephropathy were 0.79 (0.68, 0.92), 0.80 (0.67, 0.95), and 0.80 (0.68, 0.95). The association with retinopathy was weaker, with aHRs of 0.91 (0.78, 1.06), 0.91 (0.77, 1.08), and 0.98 (0.84, 1.15), respectively. CONCLUSIONS: Any level of leisure-time physical activity was associated with a lower risk of neuropathy and nephropathy but not retinopathy in individuals with type 2 diabetes. For both neuropathy and nephropathy, the minimal effective physical activity level may correspond to <1.5 h of walking per week.

• Ekelund, Ulf; Sanchez-Lastra, Miguel Adriano; Dalene, Knut Eirik & Tarp, Jakob (2023). Dose–response associations, physical activity intensity and mortality risk: A narrative review. Journal of Sport and Health Science. ISSN 2095-2546. 13(1), p. 24–29. doi: 10.1016/j.jshs.2023.09.006. Full text in Research Archive Show summary

  Physical activity is consistently associated with reduced mortality, decreased risk for non-communicable diseases, and improved mental health in observational studies. Randomized controlled trials and observational Mendelian randomization studies support causal links between physical activity and health outcomes. However, the scarcity of evidence from randomized controlled trials, along with their inherent challenges like exposure contrasts, healthy volunteer biases, loss to follow-up, and limited real-world dose–response data, warrants a comprehensive approach. This review advocates synthesizing insights from diverse study designs to better understand the causal relationship between physical activity, mortality risk, and other health outcomes. Additionally, it summarizes recent research since the publication of current physical activity recommendations. Novel observational studies utilizing device-measured physical activity underscore the importance of every minute of activity and suggest that all intensity levels confer health benefits, with vigorous-intensity potentially requiring lower volumes for substantial benefits. Future guidelines, informed by device-measured physical activity studies, may offer refined age-specific recommendations, emphasize vigorous-intensity physical activity, and include daily step counts as a simple, easily assessable metric using commercial wearables.

• Lundin, Magnus; Heiberg, Einar; Nordlund, David; Gyllenhammar, Tom; Steding-Ehrenborg, Katarina & Engblom, Henrik [Show all 26 contributors for this article] (2023). Prognostic utility and characterization of left ventricular hypertrophy using global thickness. Scientific Reports. 13(1). doi: 10.1038/s41598-023-48173-7. Full text in Research Archive Show summary

  Abstract Cardiovascular magnetic resonance (CMR) can accurately measure left ventricular (LV) mass, and several measures related to LV wall thickness exist. We hypothesized that prognosis can be used to select an optimal measure of wall thickness for characterizing LV hypertrophy. Subjects having undergone CMR were studied (cardiac patients, n = 2543; healthy volunteers, n = 100). A new measure, global wall thickness (GT, GTI if indexed to body surface area) was accurately calculated from LV mass and end-diastolic volume. Among patients with follow-up (n = 1575, median follow-up 5.4 years), the most predictive measure of death or hospitalization for heart failure was LV mass index (LVMI) (hazard ratio (HR)[95% confidence interval] 1.16[1.12–1.20], p &lt; 0.001), followed by GTI (HR 1.14[1.09–1.19], p &lt; 0.001). Among patients with normal findings (n = 326, median follow-up 5.8 years), the most predictive measure was GT (HR 1.62[1.35–1.94], p &lt; 0.001). GT and LVMI could characterize patients as having a normal LV mass and wall thickness, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy, and the three abnormal groups had worse prognosis than the normal group (p &lt; 0.05 for all). LV mass is highly prognostic when mass is elevated, but GT is easily and accurately calculated, and adds value and discrimination amongst those with normal LV mass (early disease).

• Naveed, Sehrish; Sallinen, Taisa; Eloranta, Aino-Maija; Skog, Hannamari; Jalkanen, Henna & Brage, Søren Karl [Show all 11 contributors for this article] (2023). Effects of 2-year dietary and physical activity intervention on cognition in children—a nonrandomized controlled trial. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 33(11), p. 2340–2350. doi: 10.1111/sms.14464. Full text in Research Archive Show summary

  Background and Objective: We investigated the effects of a combined dietary and PA intervention on cognition in children and whether changes in diet quality, PA, sedentary behavior (SB), and sedentary time (ST) are associated with changes in cognition. Methods: We conducted a 2-year nonrandomized controlled trial in 504 children aged 6–9 years at baseline. The children were allocated to a combined dietary and PA intervention group (n = 237) or a control group (n = 160) without blinding. Interventions: The children and their parents allocated to the intervention group had six dietary counseling sessions of 30–45 min and six PA counseling sessions of 30–45 min during the 2-year intervention period. The children were also encouraged to participate in after-school exercise clubs. Cognition was assessed by the Raven's Colored Progressive Matrices. We assessed dietary factors by 4 days food records and computed the Baltic Sea Diet Score (BSDS) as a measure of diet quality. PA and ST were assessed by a combined heart rate and body movement monitor, types of PA and SB by a questionnaire. Results: The intervention had no effect on cognition. Increased BSDS and consumption of low-fat milk and decreased consumption of red meat and sausages were associated with improved cognition over 2 years. Increased organized sports, ST, and reading were positively, while unsupervised PA, computer use, and writing were negatively associated with cognition. Conclusion: Combined dietary and PA intervention had no effect on cognition. Improved diet quality and increased organized sports and reading were associated with improved cognition.

• Tornquist, Debora; Crochemore-Silva, Inácio; Tornquist, Luciana; Mielke, Grégore I; Ekelund, Ulf & Murray, Joseph [Show all 7 contributors for this article] (2023). Trajectories of Device-Measured Physical Activity During Early Childhood and Its Determinants: Findings From the 2015 Pelotas (Brazil) Birth Cohort Study. Journal of Physical Activity and Health. ISSN 1543-3080. 20(9), p. 840–849. doi: 10.1123/jpah.2022-0608. Full text in Research Archive Show summary

  Background: The objective was to describe trajectories of physical activity (PA) measured by accelerometry during early childhood and to test associations with sociodemographic, gestational, maternal, and perinatal determinants. Methods: Data from 1798 children from the 2015 Pelotas (Brazil) Birth Cohort were analyzed. PA was measured with wrist accelerometers at 1, 2, and 4 years. PA trajectories were estimated using group-based trajectory modeling, and associations with determinants were tested using Poisson regression with robust variance. Results: Two trajectories were identified: Moderate and high PA, both showing a linear increase in PA in the first years but differing in volume. Girls (prevalence ratio [PR]: 0.91; 95% confidence interval [CI], 0.88–0.94), highly educated mothers (PR: 0.93; 95% CI, 0.88–0.97), and high birth weight children (PR: 0.91; 95% CI, 0.85–0.97) showed less probability of high PA trajectory. Birth order ≥3 (PR: 1.06; 95% CI, 1.01–1.11) was associated with higher likelihood of high PA trajectory. Conclusions: Children showed an increase in PA during the first years, with 2 trajectories that differ in PA levels. Female sex, high maternal schooling, and high birth weight reduced the probability of having a high PA trajectory, while higher birth order increased this probability. These characteristics should be considered when planning PA interventions for children in early childhood.

• Sagelv, Edvard Hamnvik; Hopstock, Laila Arnesdatter; Morseth, Bente; Hansen, Bjørge Hermann; Steene-Johannessen, Jostein & Johansson, Jonas Lars [Show all 12 contributors for this article] (2023). Device-measured physical activity, sedentary time, and risk of all-cause mortality: an individual participant data analysis of four prospective cohort studies. British Journal of Sports Medicine. ISSN 0306-3674. 57(22), p. 1457–1463. doi: 10.1136/bjsports-2022-106568. Full text in Research Archive Show summary

  Objectives - To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk.<p> <p>Methods - This study involved individual participant data analysis of four prospective cohort studies (Norway, Sweden, USA, baseline: 2003–2016, 11 989 participants ≥50 years, 50.5% women) with hip-accelerometry-measured physical activity and sedentary time. Associations were examined using restricted cubic splines and fractional polynomials in Cox regressions adjusted for sex, education, body mass index, smoking, alcohol, study cohort, cardiovascular disease, cancer, and/or diabetes, accelerometry wear time and age.<p> <p>Results - 6.7% (n=805) died during follow-up (median 5.2 years, IQR 4.2 years). More than 12 daily sedentary hours (reference 8 hours) was associated with mortality risk only among those accumulating <22 min of MVPA per day (HR 1.38, 95% CI 1.10 to 1.74). Higher MVPA levels were associated with lower mortality risk irrespective of sedentary time, for example, HR for 10 versus 0 daily min of MVPA was 0.85 (95% CI 0.74 to 0.96) in those accumulating <10.5 daily sedentary hours and 0.65 (95% CI 0.53 to 0.79) in those accumulating ≥10.5 daily sedentary hours. Joint association analyses confirmed that higher MVPA was superior to lower sedentary time in lowering mortality risk, for example, 10 versus 0 daily min of MVPA was associated with 28–55% lower mortality risk across the sedentary time spectrum (lowest risk, 10 daily sedentary hours: HR 0.45, 95% CI 0.31 to 0.65).<p> <p>Conclusions - Sedentary time was associated with higher mortality risk but only in individuals accumulating less than 22 min of MVPA per day. Higher MVPA levels were associated with lower mortality risk irrespective of the amount of sedentary time.

• Stamatakis, Emmanuel; Ahmadi, Matthew N.; Friedenreich, Christine M.; Blodgett, Joanna M.; Koster, Annemarie & Holtermann, Andreas [Show all 13 contributors for this article] (2023). Vigorous Intermittent Lifestyle Physical Activity and Cancer Incidence Among Nonexercising Adults: The UK Biobank Accelerometry Study. JAMA Oncology. ISSN 2374-2437. 9(9), p. 1255–1259. doi: 10.1001/jamaoncol.2023.1830. Full text in Research Archive Show summary

  IMPORTANCE Vigorous physical activity (VPA) is a time-efficient way to achieve recommended physical activity (PA) for cancer prevention, although structured longer bouts of VPA (via traditional exercise) are unappealing or inaccessible to many individuals. OBJECTIVES To evaluate the dose-response association of device-measured daily vigorous intermittent lifestyle physical activity (VILPA) with incident cancer, and to estimate the minimal dose required for a risk reduction of 50% of the maximum reduction. DESIGN, SETTING, AND PARTICIPANTS This was a prospective cohort analysis of 22 398 self-reported nonexercising adults from the UK Biobank accelerometry subsample. Participants were followed up through October 30, 2021 (mortality and hospitalizations), or June 30, 2021 (cancer registrations). EXPOSURES Daily VILPA of up to 1 and up to 2 minutes, assessed by accelerometers worn on participants’ dominant wrist. MAIN OUTCOMES AND MEASURES Incidence of total cancer and PA-related cancer (a composite outcome of 13 cancer sites associated with low PA levels). Hazard ratios and 95% CIs were estimated using cubic splines adjusted for age, sex, education level, smoking status, alcohol consumption, sleep duration, fruit and vegetable consumption, parental cancer history, light- and moderate-intensity PA, and VPA from bouts of more than 1 or 2 minute(s), as appropriate. RESULTS The study sample comprised 22 398 participants (mean [SD] age, 62.0 [7.6] years; 10 122 [45.2%] men and 12 276 [54.8%] women; 21 509 [96.0%] White individuals). During a mean (SD) follow-up of 6.7 (1.2) years (149 650 person-years), 2356 total incident cancer events occurred, 1084 owing to PA-related cancer. Almost all (92.3%) of VILPA was accrued in bouts of up to 1 minute. Daily VILPA duration was associated with outcomes in a near-linear manner, with steeper dose-response curves for PA-related cancer than total cancer incidence. Compared with no VILPA, the median daily VILPA duration of bouts up to 1 minute (4.5 minutes per day) was associated with an HR of 0.80 (95% CI, 0.69-0.92) for total cancer and 0.69 (95% CI, 0.55-0.86) for PA-related cancer. The minimal dose was 3.4 minutes per day for total (HR, 0.83; 95% CI, 0.73-0.93) and 3.7 minutes for PA-related (HR, 0.72; 95% CI, 0.59-0.88) cancer incidence. Findings were similar for VILPA bout of up to 2 minutes. CONCLUSIONS AND RELEVANCE The findings of this prospective cohort study indicate that small amounts of VILPA were associated with lower incident cancer risk. Daily VILPA may be a promising intervention for cancer prevention in populations not able or motivated to exercise in leisure time.

• Sanchez-Lastra, Miguel Adriano; Ding, Ding; Cruz, Borja Del Pozo; Dalene, Knut Eirik; Ayán, Carlos & Ekelund, Ulf [Show all 7 contributors for this article] (2023). Joint associations of device-measured physical activity and abdominal obesity with incident cardiovascular disease: a prospective cohort study. British Journal of Sports Medicine. ISSN 0306-3674. 58(4), p. 196–203. doi: 10.1136/bjsports-2023-107252. Full text in Research Archive Show summary

  Objective: To examine the joint associations between physical activity and abdominal obesity with the risk of cardiovascular disease (CVD) events. Methods: We included 70 830 UK Biobank participants (mean age±SD=61.6 ± 7.9 years; 56.4% women) with physical activity measured by wrist-worn accelerometers and without major chronic diseases. Participants were jointly categorised into six groups based on their physical activity level (tertiles of total volume and specific intensity levels) and presence or absence of abdominal obesity based on measured waist circumference. Associations with incident CVD (fatal and non-fatal events) were determined using proportional subdistribution hazard models with multivariable adjustment. Results: After excluding events during the first 2 years of follow-up, participants were followed for a median of 6.8 years, during which 2795 CVD events were recorded. Compared with the low abdominal adiposity and highest tertile of physical activity, abdominal obesity was associated with higher risk of incident CVD, especially in those with low levels of vigorous-intensity physical activity (HR 1.42, 95% CI 1.22 to 1.64). Approximately 500 min per week of moderate-to-vigorous intensity and approximately 30–35 min of vigorous-intensity physical activity offset the association of abdominal obesity and the risk of having a CVD event. Conclusion: Physical activity equivalent to approximately 30–35 min of vigorous intensity per week appears to offset the association between abdominal obesity and incident CVD. About 15 times more physical activity of at least moderate intensity is needed to achieve similar results.

• Varela, Andrea Ramírez; Hallal, Pedro C.; Grueso, Juliana Mejía; Pedišić, Željko; Salvo, Deborah & Nguyen, Anita [Show all 166 contributors for this article] (2023). Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity—GoPA! 2015 and 2020 Surveys. Journal of Physical Activity and Health. ISSN 1543-3080. 20(2), p. 112–128. doi: 10.1123/jpah.2022-0464. Full text in Research Archive Show summary

  Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion.

• Paluch, Amanda E.; Bajpai, Shivangi; Ballin, Marcel; Bassett, David R.; Buford, Thomas W. & Carnethon, Mercedes R. [Show all 31 contributors for this article] (2023). Prospective Association of Daily Steps with Cardiovascular Disease: A Harmonized Meta-Analysis. Circulation. ISSN 0009-7322. 147(2), p. 122–131. doi: 10.1161/CIRCULATIONAHA.122.061288. Full text in Research Archive Show summary

  Background: Taking fewer than the widely promoted “10 000 steps per day” has recently been associated with lower risk of all-cause mortality. The relationship of steps and cardiovascular disease (CVD) risk remains poorly described. A meta-analysis examining the dose–response relationship between steps per day and CVD can help inform clinical and public health guidelines. Methods: Eight prospective studies (20 152 adults [ie, ≥18 years of age]) were included with device-measured steps and participants followed for CVD events. Studies quantified steps per day and CVD events were defined as fatal and nonfatal coronary heart disease, stroke, and heart failure. Cox proportional hazards regression analyses were completed using study-specific quartiles and hazard ratios (HR) and 95% CI were meta-analyzed with inverse-variance–weighted random effects models. Results: The mean age of participants was 63.2±12.4 years and 52% were women. The mean follow-up was 6.2 years (123 209 person-years), with a total of 1523 CVD events (12.4 per 1000 participant-years) reported. There was a significant difference in the association of steps per day and CVD between older (ie, ≥60 years of age) and younger adults (ie, <60 years of age). For older adults, the HR for quartile 2 was 0.80 (95% CI, 0.69 to 0.93), 0.62 for quartile 3 (95% CI, 0.52 to 0.74), and 0.51 for quartile 4 (95% CI, 0.41 to 0.63) compared with the lowest quartile. For younger adults, the HR for quartile 2 was 0.79 (95% CI, 0.46 to 1.35), 0.90 for quartile 3 (95% CI, 0.64 to 1.25), and 0.95 for quartile 4 (95% CI, 0.61 to 1.48) compared with the lowest quartile. Restricted cubic splines demonstrated a nonlinear association whereby more steps were associated with decreased risk of CVD among older adults. Conclusions: For older adults, taking more daily steps was associated with a progressively decreased risk of CVD. Monitoring and promoting steps per day is a simple metric for clinician–patient communication and population health to reduce the risk of CVD.

• Molina-Garcia, Pablo; Notbohm, Hannah L.; Schumann, Moritz; Argent, Rob; Hetherington-Rauth, Megan & Stang, Julie [Show all 14 contributors for this article] (2022). Validity of Estimating the Maximal Oxygen Consumption by Consumer Wearables: A Systematic Review with Meta-analysis and Expert Statement of the INTERLIVE Network. Sports Medicine. ISSN 0112-1642. doi: 10.1007/s40279-021-01639-y. Full text in Research Archive Show summary

  Background: Technological advances have recently made possible the estimation of maximal oxygen consumption (VO2max) by consumer wearables. However, the validity of such estimations has not been systematically summarized using meta-analytic methods and there are no standards guiding the validation protocols. Objective: The aim was to (1) quantitatively summarize previous studies investigating the validity of the VO2max estimated by consumer wearables and (2) provide best-practice recommendations for future validation studies. Methods: First, we conducted a systematic review and meta-analysis of studies validating the estimation of VO2max by wearables. Second, based on the state of knowledge (derived from the systematic review) combined with the expert discussion between the members of the Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) consortium, we provided a set of best-practice recommendations for validation protocols. Results: Fourteen validation studies were included in the systematic review and meta-analysis. Meta-analysis results revealed that wearables using resting condition information in their algorithms significantly overestimated VO2max (bias 2.17 ml·kg−1·min−1; limits of agreement − 13.07 to 17.41 ml·kg−1·min−1), while devices using exercise-based information in their algorithms showed a lower systematic and random error (bias − 0.09 ml·kg−1·min−1; limits of agreement − 9.92 to 9.74 ml·kg−1·min−1). The INTERLIVE consortium proposed six key domains to be considered for validating wearable devices estimating VO2max, concerning the following: the target population, reference standard, index measure, testing conditions, data processing, and statistical analysis. Conclusions: Our meta-analysis suggests that the estimations of VO2max by wearables that use exercise-based algorithms provide higher accuracy than those based on resting conditions. The exercise-based estimation seems to be optimal for measuring VO2max at the population level, yet the estimation error at the individual level is large, and, therefore, for sport/clinical purposes these methods still need improvement. The INTERLIVE network hereby provides best-practice recommendations to be used in future protocols to move towards a more accurate, transparent and comparable validation of VO2max derived from wearables.

• Dalene, Knut Eirik; Kolle, Elin; Steene-Johannessen, Jostein; Hansen, Bjørge Hermann; Ekelund, Ulf & Grydeland, May [Show all 8 contributors for this article] (2022). Device-measured sedentary time in Norwegian children and adolescents in the era of ubiquitous internet access: secular changes between 2005, 2011 and 2018. International Journal of Epidemiology. ISSN 0300-5771. 51(5), p. 1556–1567. doi: 10.1093/ije/dyac063. Full text in Research Archive Show summary

  Background: Access to screen-based media has been revolutionized during the past two decades. How this has affected sedentary time (ST) accumulation in children is poorly understood. Methods: This study, based on the Physical Activity among Norwegian Children Study (PANCS), uses accelerometer data from population-based samples of 9- and 15‐year-olds, collected in 2005 (n = 1722), 2011 (n = 1587) and 2018 (n = 1859). Secular changes between surveys were analysed using random-effects linear regression models adjusted for survey-specific factors. Data on ST were collected using hip-worn ActiGraphs and ST was defined using a threshold equivalent to <100 counts/min. Sedentary bouts were grouped by duration: <1, 1–5, 5–15, 15–30 and ≥30 min. Results: Between 2005 and 2018, ST increased by 29 min/day in 9-year-old boys (95% CI: 19, 39; P <0.001), by 21 min/day in 15-year-old boys (95% CI: 8, 34; P = 0.002) and by 22 min/day in 15-year-old girls (95% CI: 10, 35; P <0.001), but not in 9-year-old girls at 6 min/day (95% CI: -3, 16; P = 0.191). All age-sex groups accumulated less ST in bouts lasting <5 min and more ST in longer bouts, particularly in 5–15-min bouts. Adolescent girls also increased ST accumulation in 15–30-min and ≥30-min bouts. Changes were largely mirrored before, during and after school on weekdays and during weekend days. Conclusions: Coinciding with the introduction of smartphones, tablets and near-universal internet access, total daily ST and ST accumulated in prolonged sedentary bouts increased between 2005 and 2018 in children and adolescents.

• Yamada, Yosuke; Zhang, Xueying; Henderson, Mary E T; Sagayama, Hiroyuki; Pontzer, Herman & Watanabe, Daiki [Show all 92 contributors for this article] (2022). Variation in human water turnover associated with environmental and lifestyle factors. Science. ISSN 0036-8075. 378(6622), p. 909–915. doi: 10.1126/science.abm8668. Full text in Research Archive Show summary

  Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (2H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.

• Ding, Ding; Buskirk, Joe Van; Nguyen, Binh; Stamatakis, Emmanuel; Elbarbary, Mona & Veronese, Nicola [Show all 10 contributors for this article] (2022). Physical activity, diet quality and all-cause cardiovascular disease and cancer mortality: A prospective study of 346 627 UK Biobank participants. British Journal of Sports Medicine. ISSN 0306-3674. 56(20), p. 1148–1156. doi: 10.1136/bjsports-2021-105195. Full text in Research Archive Show summary

  Objectives: To examine independent and interactive associations of physical activity and diet with all-cause, cardiovascular disease (CVD) and physical activity, diet and adiposity-related (PDAR) cancer mortality. Methods: This population-based prospective cohort study (n=346 627) is based on the UK Biobank data with linkage to the National Health Service death records to 30 April 2020. A left-truncated Cox proportional hazards model was fitted to examine the associations between exposures (self-reported total moderate-to-vigorous intensity physical activity (MVPA), vigorous-intensity physical activity (VPA) and a diet quality index (score ranged 0–3)) and outcomes (all-cause, CVD and PDAR cancer mortality). Results: During a median follow-up of 11.2 years, 13 869 participants died from all causes, 2650 from CVD and 4522 from PDAR cancers. Compared with quartile 1 (Q1, 0–210 min/week), Q2–Q4 of MVPA were associated with lower risks of all-cause (HR ranged from 0.87 (95% CI: 0.83 to 0.91) to 0.91 (95% CI: 0.87 to 0.96)), CVD (HR ranged from 0.85 (95% CI: 0.76 to 0.95) to 0.90 (95% CI: 0.81 to 1.00)) and PDAR cancer mortality (HR ranged from 0.86 (95% CI: 0.79 to 0.93) to 0.94 (95% CI: 0.86 to 1.02)). Compared with no VPA, any VPA was associated with lower risk for all-cause and CVD mortality (HR ranged from 0.85 (95% CI: 0.80 to 0.89) to 0.88 (95% CI: 0.84 to 0.93) and from 0.75 (95% CI: 0.68 to 0.83) to 0.90 (95% CI: 0.80 to 1.02), respectively). Although not reaching statistical significance for all-cause and CVD mortality, being in the best dietary category (diet quality index=2–3) was associated with a reduction in PDAR cancer mortality (HR=0.86, 95% CI: 0.78 to 0.93). No additive or multiplicative interactions between physical activity categories and dietary quality was found. When comparing across physical activity and diet combinations, the lowest risk combinations consistently included the higher levels of physical activity and the highest diet quality score. Conclusions: Adhering to both quality diet and sufficient physical activity is important for optimally reducing the risk of mortality from all causes, CVD and PDAR cancers.

• Kwon, Soyang; Menezes, Ana M. B.; Ekelund, Ulf; Wehrmeister, Fernando C.; Gonçalves, Helen & Silva, Bruna Gonçalves C. da [Show all 7 contributors for this article] (2022). Longitudinal change in physical activity and adiposity in the transition from adolescence to early adulthood: the 1993 Pelotas cohort study. International Journal of Behavioral Nutrition and Physical Activity. 19. doi: 10.1186/s12966-022-01321-0. Full text in Research Archive Show summary

  Background: In the current Physical Activity Guidelines (PAG) for moderate- and vigorous-intensity physical activity (MVPA), abrupt transition from ≥ 60 min/day [youth PAG] to ≥ 150 min/week (≥ 22 min/day on average) [adult PAG] during emerging adulthood is poorly justified. The aim of this study was to examine body fat mass changes according to whether meeting the youth and adult PAGs in late adolescence (age 18 years) to early adulthood (age 22 years). Methods: The study sample included 2,099 participants (1,113 females) from the 1993 Pelotas (Brazil) Study. At ages 18 and 22 years, MVPA was measured using wrist-worn accelerometry and fat mass was measured using dual-energy X-ray absorptiometry. MVPA at age 18 was categorized into two groups: 0–59 or ≥ 60 min/day (no [N] or yes [Y] for meeting the youth recommendation, respectively). MVPA at age 22 was categorized into three groups: 0–21, 22–59, or ≥ 60 min/day (N, Y22, or Y60 for not meeting the adult recommendation, meeting the adult recommendation, or meeting the youth recommendation, respectively). The combination of these groups created six MVPA groups (N&N, N&Y22, N&Y60, Y&N, Y&Y22, and Y&Y60). Sex-specific multivariable linear regression analyses were conducted to estimate change in fat mass index (FMI) from age 18 to 22 years in the six MVPA groups. Results: Among males, compared to Y&Y60 (FMI increase = 1.2 kg/m2 [95% CI = 1.0, 1.4]), Y&Y22 and Y&N had larger FMI increases (1.9 [1.6, 2.1] and 1.9 [1.2, 2.5], respectively). Among females, Y&Y60 and Y&Y22 had an equal FMI increase (1.6 [1.4, 1.9] for both groups), while Y&N had a larger FMI increase (2.4 [1.8, 3.0]). Conclusions: These findings suggest that among those who were active in late adolescence, engaging in ≥ 22 min/day of MVPA in adulthood is associated with lower body fat gain for females, but not for males.

• Bielemann, Renata M.; Oliveira, Ricardo; Bertoldi, Andréa D.; Tomasi, Elaine; Demarco, Flávio F. & Gonzalez, Maria Cristina [Show all 9 contributors for this article] (2022). Objective and Self-Reported Physical Activity and Risk of Falling Among Community-Dwelling Older Adults From Southern Brazil. Journal of Aging and Physical Activity. ISSN 1063-8652. 30(6), p. 972–979. doi: 10.1123/japa.2021-0148. Full text in Research Archive Show summary

  This study evaluated prospective associations between self-reported and objectively measured physical activity (PA) and risk of falls among older adults. A cohort study started in 2014 with 1,451 community-dwelling older adults living in Pelotas, Brazil. Leisure-time PA was obtained by the International Physical Activity Questionnaire and 7-day raw accelerometer data evaluated for total, light PA, and moderate to vigorous PA. In 2016–2017, participants recorded their falls in the previous 12 months. Around 23% of the 1,161 participants followed-up in 2016–2017 experienced a fall in the last 12 months. Participants who did not spend any time in self-reported leisure-time PA at baseline had on average 34% higher risk of falls, and individuals in the lowest tertile for moderate to vigorous PA had on average 51% higher risk of falls compared to those in the highest tertile. Low levels of self-reported and objectively measured moderate to vigorous PA were related to higher risk of falling among Brazilian older adults.

• Argent, Rob; Hetherington-Rauth, Megan; Stang, Julie; Tarp, Jakob; Ortega, Francisco B. & Molina-Garcia, Pablo [Show all 14 contributors for this article] (2022). Recommendations for Determining the Validity of Consumer Wearables and Smartphones for the Estimation of Energy Expenditure: Expert Statement and Checklist of the INTERLIVE Network. Sports Medicine. ISSN 0112-1642. 52(8), p. 1817–1832. doi: 10.1007/s40279-022-01665-4. Full text in Research Archive Show summary

  Background: Consumer wearables and smartphone devices commonly offer an estimate of energy expenditure (EE) to assist in the objective monitoring of physical activity to the general population. Alongside consumers, healthcare professionals and researchers are seeking to utilise these devices for the monitoring of training and improving human health. However, the methods of validation and reporting of EE estimation in these devices lacks rigour, negatively impacting on the ability to make comparisons between devices and provide transparent accuracy. Objectives: The Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The network was founded in 2019 and strives towards developing best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice validation protocol for consumer wearables and smartphones in the estimation of EE. Methods: The recommendations were developed through (1) a systematic literature review; (2) an unstructured review of the wider literature discussing the potential factors that may introduce bias during validation studies; and (3) evidence-informed expert opinions from members of the INTERLIVE network. Results: The systematic literature review process identified 1645 potential articles, of which 62 were deemed eligible for the final dataset. Based on these studies and the wider literature search, a validation framework is proposed encompassing six key domains for validation: the target population, criterion measure, index measure, testing conditions, data processing and the statistical analysis. Conclusions: The INTERLIVE network recommends that the proposed protocol, and checklists provided, are used to standardise the testing and reporting of the validation of any consumer wearable or smartphone device to estimate EE. This in turn will maximise the potential utility of these technologies for clinicians, researchers, consumers, and manufacturers/developers, while ensuring transparency, comparability, and replicability in validation.

• Ikeda, Erika; Guagliano, Justin M.; Atkin, Andrew J.; Sherar, Lauren B.; Ekelund, Ulf & Hansen, Bjørge Hermann [Show all 8 contributors for this article] (2022). Cross-sectional and longitudinal associations of active travel, organised sport and physical education with accelerometer-assessed moderate-to-vigorous physical activity in young people: the International Children’s Accelerometry Database. International Journal of Behavioral Nutrition and Physical Activity. 19. doi: 10.1186/s12966-022-01282-4. Full text in Research Archive Show summary

  Background Physical activity (PA) declines during childhood. Important sources of PA are active travel, organised sport and physical education (PE), but it is unclear how these domain-specific PA sources contribute to (changes in) daily moderate-to-vigorous PA (MVPA) in young people. This study aimed to examine (1) the cross-sectional association between domain-specific physical activity (i.e., active travel, organised sport and PE) and daily minutes in accelerometer-assessed MVPA; and (2) the longitudinal association between domain-specific physical activity at baseline and change in daily minutes in MVPA. Methods Participants (baseline age 11.3 ± .1.2 years) were drawn from three studies in the International Children’s Accelerometry Database. The contribution of self-reported standardised active travel, organised sport and PE to accelerometer-measured daily minutes in MVPA was examined using linear regression. In cross-sectional analyses, MVPA was regressed on each PA domain in separate models, adjusted for study, age, sex, maternal education, season, and monitor wear time. In longitudinal analyses, change in MVPA was regressed on each of the baseline PA domains, additionally adjusting for changes in season and wear time, follow-up duration, and baseline MVPA. R-squared was used to compare variance explained by each PA domain. Results In the cross-sectional analyses (n = 3871), organised sport (standardised β = 3.81, 95% confidence interval [95%CI] = 3.06, 4.56) and active travel (β = 3.46, 95%CI = 2.73, 4.19) contributed more to daily MVPA than PE (β = 0.82, 95%CI = -0.02, 1.66). Compared to the base model which included only covariates (R2 = 21.5%), organised sport (absolute change: + 1.9%) and active travel (+ 1.7%) models explained more of the variance than the PE model (± < 0.1%). Associations followed a similar pattern in the longitudinal analyses (n = 2302), but none of the PA domains predicted change in MVPA (organised sport: standardised β = 0.85, 95%CI = -0.03, 1.72; active travel: β = 0.68, 95%CI = -0.14, 1.50; PE: β = 0.02, 95%CI = -0.87, 0.91). Conclusions A multi-sectoral approach covering a wide range of PA domains should be promoted to minimise the age-related decline in MVPA during childhood.

• Jones, Paul Remy; Rajalahti, Tarja; Resaland, Geir Kåre; Aadland, Eivind; Steene-Johannessen, Jostein & Anderssen, Sigmund Alfred [Show all 10 contributors for this article] (2022). Associations of lipoprotein particle profile and objectively measured physical activity and sedentary time in schoolchildren: a prospective cohort study. International Journal of Behavioral Nutrition and Physical Activity. 19(1). doi: 10.1186/s12966-022-01244-w. Full text in Research Archive Show summary

  Background: Our understanding of the mechanisms through which physical activity might benefit lipoprotein metabolism is inadequate. Here we characterise the continuous associations between physical activity of different intensities, sedentary time, and a comprehensive lipoprotein particle profile. Methods: Our cohort included 762 fifth grade (mean [SD] age = 10.0 [0.3] y) Norwegian schoolchildren (49.6% girls) measured on two separate occasions across one school year. We used targeted proton nuclear magnetic resonance (1H NMR) spectroscopy to produce 57 lipoprotein measures from fasted blood serum samples. The children wore accelerometers for seven consecutive days to record time spent in light-, moderate-, and vigorous-intensity physical activity, and sedentary time. We used separate multivariable linear regression models to analyse associations between the device-measured activity variables—modelled both prospectively (baseline value) and as change scores (follow-up minus baseline value)—and each lipoprotein measure at follow-up. Results: Higher baseline levels of moderate-intensity and vigorous-intensity physical activity were associated with a favourable lipoprotein particle profile at follow-up. The strongest associations were with the larger subclasses of triglyceride-rich lipoproteins. Sedentary time was associated with an unfavourable lipoprotein particle profile, the pattern of associations being the inverse of those in the moderate-intensity and vigorous-intensity physical activity analyses. The associations with light-intensity physical activity were more modest; those of the change models were weak. Conclusion: We provide evidence of a prospective association between time spent active or sedentary and lipoprotein metabolism in schoolchildren. Change in activity levels across the school year is of limited influence in our young, healthy cohort.

• Gammon, Catherine; Atkin, Andrew J.; Corder, Kirsten; Ekelund, Ulf; Hansen, Bjørge Hermann & Sherar, Lauren B. [Show all 19 contributors for this article] (2022). Influence of Guideline Operationalization on Youth Activity Prevalence in the International Children's Accelerometry Database. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 54(7), p. 1114–1122. doi: 10.1249/MSS.0000000000002884. Full text in Research Archive Show summary

  Introduction The United Kingdom and World Health Organization recently changed their youth physical activity (PA) guidelines from 60 min of moderate- to vigorous-intensity PA (MVPA) every day, to an average of 60 min of MVPA per day, over a week. The changes are based on expert opinion due to insufficient evidence comparing health outcomes associated with different guideline definitions. This study used the International Children’s Accelerometry Database to compare approaches to calculating youth PA compliance and associations with health indicators. Methods Cross-sectional accelerometer data (n = 21,612, 5–18 yr) were used to examine compliance with four guideline definitions: daily method (DM; ≥60 min MVPA every day), average method (AM; average of ≥60 min MVPA per day), AM5 (AM compliance and ≥5 min of vigorous PA [VPA] on ≥3 d), and AM15 (AM compliance and ≥15 min VPA on ≥3 d). Associations between compliance and health indicators were examined for all definitions. Results Compliance varied from 5.3% (DM) to 29.9% (AM). Associations between compliance and health indicators were similar for AM, AM5, and AM15. For example, compliance with AM, AM5, and AM15 was associated with a lower BMI z-score (statistics are coefficient [95% CI]): AM (−0.28 [−0.33 to −0.23]), AM5 (−0.28 [−0.33 to −0.23], and AM15 (−0.30 [−0.35 to −0.25]). Associations between compliance and health indicators for DM were similar/weaker, possibly reflecting fewer DM-compliant participants with health data and lower variability in exposure/outcome data. Conclusions Youth completing 60 min of MVPA every day do not experience superior health benefits to youth completing an average of 60 min of MVPA per day. Guidelines should encourage youth to achieve an average of 60 min of MVPA per day. Different guideline definitions affect inactivity prevalence estimates; this must be considered when analyzing data and comparing studies.

• Wang, Zhe; Emmerich, Andrew; Pillon, Nicolas J.; Moore, Tim; Hemerich, Daiane & Cornelis, Marilyn C. [Show all 227 contributors for this article] (2022). Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention. Nature Genetics. ISSN 1061-4036. 54(9), p. 1332–1344. doi: 10.1038/s41588-022-01165-1. Full text in Research Archive Show summary

  Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type IIA muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention.

• Halsey, Lewis G.; Careau, Vincent; Pontzer, Herman; Ainslie, Philip N.; Andersen, Lene Frost & Anderson, Liam J. [Show all 83 contributors for this article] (2022). Variability in energy expenditure is much greater in males than females. Journal of Human Evolution. ISSN 0047-2484. 171. doi: 10.1016/j.jhevol.2022.103229. Full text in Research Archive Show summary

  In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction.

• Tarp, Jakob; Rossen, Jenny; Ekelund, Ulf & Dohrn, Ing-Mari (2022). Joint associations of physical activity and sedentary time with body mass index: A prospective study of mortality risk. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. doi: 10.1111/sms.14297. Full text in Research Archive Show summary

  Device-measured physical activity and sedentary time are suggested to be more important determinants of all-cause mortality compared to body mass index (BMI) in mainly older adults. However, the joint associations of physical activity and sedentary time with BMI in relation to mortality risk in relatively healthy middle-aged individuals are unclear. We followed 770 adults (56% women, mean age 55.6 years) from a population-based cohort study for up to 15.3 years. BMI categories were combined with tertiles of total, light, and moderate-to-vigorous physical activity and sedentary time. Cox proportional hazards models estimated hazard ratios (HR) of all-cause mortality with 95% confidence intervals (CI). High total and light intensity physical activity and low sedentary time were associated with a lower risk of mortality in normal weight individuals compared with low active overweight/obese; HR: 0.35 (CI: 0.14, 0.86), HR: 0.33 (CI: 0.12, 0.89), and HR: 0.34 (CI: 0.13, 0.92). Among overweight/obese individuals, those who were medium active in light physical activity had a lower mortality risk, HR: 0.36 (CI: 0.15, 0.83), compared with low active. Medium sedentary individuals had a lower risk, HR: 0.43 (CI: 0.20, 0.94) compared with those who were most sedentary. Associations among the most active or least sedentary tertiles were similar irrespective of BMI category. In conclusion, higher physical activity and lower sedentary time were associated with lower mortality risk irrespective of BMI. Physical activity should be promoted and prescribed to individuals with low physical activity levels irrespective of weight status.

• Smidt, Melony C. Fortuin-de; Sewe, Maquins Odhiambo; Lassale, Camille; Weiderpass, Elisabete; Andersson, Jonas & Huerta, José María [Show all 41 contributors for this article] (2022). Physical activity attenuates but does not eliminate coronary heart disease risk amongst adults with risk factors: EPIC-CVD case-cohort study. European Journal of Preventive Cardiology (EJPC). ISSN 2047-4873. 29(12), p. 1618–1629. doi: 10.1093/eurjpc/zwac055. Full text in Research Archive Show summary

  Aims: This study aimed to evaluate the association between physical activity and the incidence of coronary heart disease (CHD) in individuals with and without CHD risk factors. Methods and results: EPIC-CVD is a case-cohort study of 29 333 participants that included 13 582 incident CHD cases and a randomly selected sub-cohort nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Self-reported physical activity was summarized using the Cambridge physical activity index (inactive, moderately inactive, moderately active, and active). Participants were categorized into sub-groups based on the presence or the absence of the following risk factors: obesity (body mass index ≥30 kg/m2), hypercholesterolaemia (total cholesterol ≥6.2 mmol/L), history of diabetes, hypertension (self-reported or ≥140/90 mmHg), and current smoking. Prentice-weighted Cox regression was used to assess the association between physical activity and incident CHD events (non-fatal and fatal). Compared to inactive participants without the respective CHD risk factor (referent), excess CHD risk was highest in physically inactive and lowest in moderately active participants with CHD risk factors. Corresponding excess CHD risk estimates amongst those with obesity were 47% [95% confidence interval (CI) 32–64%] and 21% (95%CI 2–44%), with hypercholesterolaemia were 80% (95%CI 55–108%) and 48% (95%CI 22–81%), with hypertension were 80% (95%CI 65–96%) and 49% (95%CI 28–74%), with diabetes were 142% (95%CI 63–260%), and 100% (95%CI 32–204%), and amongst smokers were 152% (95%CI 122–186%) and 109% (95%CI 74–150%). Conclusions: In people with CHD risk factors, moderate physical activity, equivalent to 40 mins of walking per day, attenuates but does not completely offset CHD risk.

• Martinez-Gomez, David; Cabanas-Sanchez, Veronica; Yu, Tsung; Rodriguez-Artalejo, Fernando; Ding, Ding & Lee, I-Min [Show all 7 contributors for this article] (2022). Long-term leisure-time physical activity and risk of all-cause and cardiovascular mortality: Dose-response associations in a prospective cohort study of 210 327 Taiwanese adults. British Journal of Sports Medicine. ISSN 0306-3674. 56, p. 919–926. doi: 10.1136/bjsports-2021-104961. Full text in Research Archive Show summary

  Objectives: We aimed to investigate the dose–response associations of long-term leisure-time physical activity (LTPA) obtained from repeated measures with all-cause and cardiovascular disease (CVD) mortality outcomes in Taiwanese adults. Methods: We included 210 327 participants with self-reported LTPA at least in two medical examinations (867 968 data points) for up to 20 years (median, IQR: 4.8 years, 2.3–9.0). Dose–response relationships were modelled with restricted cubic spline functions and Cox regressions HRs (95% CIs) adjusted for main covariates. Results: During up to 23 years of follow-up (3 655 734 person-years), 10 539 participants died, of which 1919 of CVD. We observed an inverse, non-linear dose–response association between long-term LTPA and all-cause and CVD mortality. Compared with the referent (0 metabolic equivalent of task (MET) hours/week), insufficient (0.01–7.49 MET hours/week), recommended (7.50–15.00 MET hours/week) and additional (>15 MET hours/week) amounts of LTPA had a lower mortality risk of 0.74 (0.69–0.80), 0.64 (0.60–0.70) and 0.59 (0.54–0.64) for all-cause mortality and 0.68 (0.60–0.84), 0.56 (0.47–0.67) and 0.56 (0.47–0.68) for CVD mortality. When using only baseline measures of LTPA, the corresponding mortality risk was 0.88 (0.84–0.93), 0.83 (0.78–0.88) and 0.78 (0.73–0.83) for all-cause and 0.91 (0.81–1.02), 0.78 (0.68–0.89) and 0.80 (0.70–0.92) for CVD mortality. Conclusion: Long-term LTPA was associated with lower risks of all-cause and CVD mortality. The magnitude of risk reductions was larger when modelling repeated measures of LTPA compared with one measure of LTPA at baseline.

• Kwon, Soyang; Ekelund, Ulf; Kandula, Namratha R. & Janz, Kathleen F. (2022). Joint associations of physical activity and sedentary time with adiposity during adolescence: ALSPAC. European Journal of Public Health. ISSN 1101-1262. 32(3), p. 347–353. doi: 10.1093/eurpub/ckac023. Full text in Research Archive Show summary

  Background: In developing evidence-based physical activity (PA) guidelines for youth, a knowledge gap exists regarding the health effects of sedentary time (SED). The aim of this study was to determine the joint associations of moderate- and vigorous-intensity PA (MVPA) and SED with adiposity during adolescence. Methods: The study sample was 2619 non-obese participants (56.7% female) from the UK Avon Longitudinal Study of Parents and Children. Accelerometer-measured MVPA and SED at age 11, 13, 15 years and self-reported TV viewing at age 13 and 16 years were used to create two exposure variables: six MVPA&SED combinations based on two MVPA patterns [≥60 (active) and <60 min/day (inactive)] and three SED patterns [≈25 (low), ≈30 (middle) and ≈35 min/h (high)] and six MVPA&TV combinations based on two MVPA patterns and three TV viewing patterns [<1–2 (low), 1–2 (middle) and >1–2 h/day (high)]. Adiposity was evaluated using fat mass index (FMI) at age 17 years. Results: SED was not significantly associated with FMI in either active or inactive adolescents. However, higher TV viewing was associated with higher FMI in both active [adjusted FMI = 4.53 vs. 5.09 (95% CI = 4.87, 5.33) for low TV vs. high TV] and inactive adolescents [adjusted FMI = 4.91 vs. 5.21 (95% CI = 5.02, 5.39) for low TV vs. high TV]. Conclusions: Higher TV viewing time, but not total SED, was prospectively associated with higher adiposity among both active and inactive adolescents, suggesting a specific sedentary behavior target for public health.

• Rimbach, Rebecca; Yamada, Yosuke; Sagayama, Hiroyuki; Ainslie, Philip N.; Andersen, Lene Frost & Anderson, Liam J. [Show all 82 contributors for this article] (2022). Total energy expenditure is repeatable in adults but not associated with short-term changes in body composition. Nature Communications. 13(1). doi: 10.1038/s41467-021-27246-z. Full text in Research Archive Show summary

  Low total energy expenditure (TEE, MJ/d) has been a hypothesized risk factor for weight gain, but repeatability of TEE, a critical variable in longitudinal studies of energy balance, is understudied. We examine repeated doubly labeled water (DLW) measurements of TEE in 348 adults and 47 children from the IAEA DLW Database (mean ± SD time interval: 1.9 ± 2.9 y) to assess repeatability of TEE, and to examine if TEE adjusted for age, sex, fat-free mass, and fat mass is associated with changes in weight or body composition. Here, we report that repeatability of TEE is high for adults, but not children. Bivariate Bayesian mixed models show no among or within-individual correlation between body composition (fat mass or percentage) and unadjusted TEE in adults. For adults aged 20–60 y (N = 267; time interval: 7.4 ± 12.2 weeks), increases in adjusted TEE are associated with weight gain but not with changes in body composition; results are similar for subjects with intervals >4 weeks (N = 53; 29.1 ± 12.8 weeks). This suggests low TEE is not a risk factor for, and high TEE is not protective against, weight or body fat gain over the time intervals tested.

• Paluch, Amanda E; Bajpai, Shivangi; Bassett, David R; Carnethon, Mercedes R; Ekelund, Ulf & Evenson, Kelly R [Show all 45 contributors for this article] (2022). Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts. The Lancet Public Health. ISSN 2468-2667. 7(3), p. e219–e228. doi: 10.1016/S2468-2667(21)00302-9. Full text in Research Archive Show summary

  Background Although 10000 steps per day is widely promoted to have health benefits, there is little evidence to support this recommendation. We aimed to determine the association between number of steps per day and stepping rate with all-cause mortality.<p> <p>Methods In this meta-analysis, we identified studies investigating the effect of daily step count on all-cause mortality in adults (aged ≥18 years), via a previously published systematic review and expert knowledge of the field. We asked participating study investigators to process their participant-level data following a standardised protocol. The primary outcome was all-cause mortality collected from death certificates and country registries. We analysed the dose– response association of steps per day and stepping rate with all-cause mortality. We did Cox proportional hazards regression analyses using study-specific quartiles of steps per day and calculated hazard ratios (HRs) with inversevariance weighted random effects models. <p>Findings We identified 15 studies, of which seven were published and eight were unpublished, with study start dates between 1999 and 2018. The total sample included 47 471 adults, among whom there were 3013 deaths (10·1 per 1000 participant-years) over a median follow-up of 7·1 years ([IQR 4·3–9·9]; total sum of follow-up across studies was 297 837 person-years). Quartile median steps per day were 3553 for quartile 1, 5801 for quartile 2, 7842 for quartile 3, and 10 901 for quartile 4. Compared with the lowest quartile, the adjusted HR for all-cause mortality was 0·60 (95% CI 0·51–0·71) for quartile 2, 0·55 (0·49–0·62) for quartile 3, and 0·47 (0·39–0·57) for quartile 4. Restricted cubic splines showed progressively decreasing risk of mortality among adults aged 60 years and older with increasing number of steps per day until 6000–8000 steps per day and among adults younger than 60 years until 8000–10000 steps per day. Adjusting for number of steps per day, comparing quartile 1 with quartile 4, the association between higher stepping rates and mortality was attenuated but remained significant for a peak of 30 min (HR 0·67 [95% CI 0·56–0·83]) and a peak of 60 min (0·67 [0·50–0·90]), but not significant for time (min per day) spent walking at 40 steps per min or faster (1·12 [0·96–1·32]) and 100 steps per min or faster (0·86 [0·58–1·28]). <p>Interpretation Taking more steps per day was associated with a progressively lower risk of all-cause mortality, up to a level that varied by age. The findings from this meta-analysis can be used to inform step guidelines for public health promotion of physical activity.

• Tarp, Jakob; Grøntved, Anders; Sanchez-Lastra, Miguel A.; Dalene, Knut Eirik; Ding, Ding & Ekelund, Ulf (2021). Fitness, fatness, and mortality in men and women from the UK biobank: Prospective cohort study. Journal of the American Heart Association (JAHA). 10(6). doi: 10.1161/JAHA.120.019605. Full text in Research Archive Show summary

  Background: Cardiorespiratory fitness may moderate the association between obesity and all‐cause mortality (ie, the “fat‐but‐fit” hypothesis), but unaddressed sources of bias are a concern. Methods and Results: Cardiorespiratory fitness was estimated as watts per kilogram from a submaximal bicycle test in 77 169 men and women from the UK Biobank cohort and combined with World Health Organization standard body mass index categories, yielding 9 unique fitness‐fatness combinations. We also formed fitness‐fatness combinations based on bioimpedance as a direct measure of body composition. All‐cause mortality was ascertained from death registries. Multivariable‐adjusted Cox regression models were used to estimate hazard ratios and 95% CIs. We examined the association between fitness‐fatness combinations and all‐cause mortality in models with progressively more conservative approaches for accounting for reverse causation, misclassification of body composition, and confounding. Over a median follow‐up of 7.7 years, 1731 participants died. In our base model, unfit men and women had higher risk of premature mortality irrespective of levels of adiposity, compared with the normal weight–fit reference. This pattern was attenuated but maintained with more conservative approaches in men, but not in women. In analysis stratified by sex and excluding individuals with prevalent major chronic disease and short follow‐up and using direct measures of body composition, mortality risk was 1.78 (95% CI, 1.17–2.71) times higher in unfit‐obese men but not higher in obese‐fit men (0.94 [95% CI, 0.60–1.48]). In contrast, there was no increased risk in obese‐unfit women (1.09 [95% CI, 0.44–1.05]) as compared with the reference. Conclusions: Cardiorespiratory fitness modified the association between obesity and mortality in men, but this pattern appeared susceptible to biases in women.

• Iurilli, Maria Laura Caminia; Zhou, Bin; Bennett, James E.; Carrillo-Larco, Rodrigo M.; Sophiea, Marisa K. & Rodriguez-Martinez, Andrea [Show all 77 contributors for this article] (2021). Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight. eLIFE. 10. doi: 10.7554/eLife.60060. Full text in Research Archive Show summary

  From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.

• Solberg, Runar Barstad; Steene-Johannessen, Jostein; Fagerland, Morten; Anderssen, Sigmund Alfred; Berntsen, Sveinung & Resaland, Geir Kåre [Show all 9 contributors for this article] (2021). Aerobic fitness mediates the intervention effects of a school-based physical activity intervention on academic performance. The school in Motion study – A cluster randomized controlled trial. Preventive Medicine Reports. 24. doi: 10.1016/j.pmedr.2021.101648. Full text in Research Archive Show summary

  Little information exists on the mechanism of how physical activity interventions effects academic performance. We examined whether the effects of a school-based physical activity intervention on academic performance were mediated by aerobic fitness. The School in Motion study was a nine-month cluster randomized controlled trial between September 2017 and June 2018. Students from 30 Norwegian lower secondary schools (N = 2,084, mean age [SD] = 14 [0.3] years) were randomly assigned into three groups: the Physically Active Learning (PAL) intervention (n = 10), the Don’t Worry—Be Happy (DWBH) intervention (n = 10), or control (n = 10). Aerobic fitness was assessed by the Andersen test and academic performance by national tests in reading and numeracy. Mediation was assessed according to the causal steps approach using linear mixed models. In the PAL intervention, aerobic fitness partially mediated the intervention effect on numeracy by 28% from a total effect of 1.73 points (95% CI: 1.13 to 2.33) to a natural direct effect of 1.24 points (95% CI: 0.58 to 1.91), and fully mediated the intervention effect on reading, with the total effect of 0.89 points (95% CI: 0.15 to 1.62) reduced to the natural direct effect of 0.40 points (95% CI: −0.48 to 1.28). Aerobic fitness did not mediate the effects on academic performance in the DWBH intervention. As aerobic fitness mediated the intervention effect on academic performance in one intervention, physical activity of an intensity that increases aerobic fitness is one strategy to improve academic performance among adolescents.

• Careau, Vincent; Halsey, Lewis G.; Pontzer, Herman; Ainslie, Philip N.; Andersen, Lene F. & Anderson, Liam J. [Show all 84 contributors for this article] (2021). Energy compensation and adiposity in humans. Current Biology. ISSN 0960-9822. 31(20). doi: 10.1016/j.cub.2021.08.016. Full text in Research Archive Show summary

  Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity energy expenditures.1, 2, 3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response—energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.

• Sanchez-Lastra, Miguel A.; Ding, Ding; Dalene, Knut Eirik; Pozo-Cruz, Borja Del; Ekelund, Ulf & Tarp, Jakob (2021). Stair climbing and mortality: a prospective cohort study from the UK Biobank. Journal of Cachexia, Sarcopenia and Muscle. ISSN 2190-5991. 12(2), p. 298–307. doi: 10.1002/jcsm.12679. Full text in Research Archive Show summary

  Background: Regular stair climbing has the potential to lower the risk of premature death, but current evidence is scarce. We aimed to examine whether daily stair climbing is associated with lower risk of all-cause, cancer, and cardiovascular disease (CVD) mortality. Methods: Using the UK Biobank cohort, we extracted information of self-reported daily flights of stairs climbed at home, categorized as none, 1 to 5, 6 to 10, 11 to 15, and ≥16 flights per day. Associations between flights of stair climbed per day and mortality were examined as hazard ratios (HRs) from Cox proportional hazards models adjusted for demographic, clinical, and behavioural covariates including time spent in other physical activities. We calculated the restricted mean survival time as an absolute measure of association. The risk of residual confounding was examined using propensity score matching and by using lung cancer as negative control outcome. Participants were followed from baseline (2006–2010) through 31 March 2020. Results: A total of 280 423 participants (median follow-up 11.1 years, during which 9445 deaths occurred) were included. Compared with not climbing any stairs, climbing more than five flights of stairs at home per day was associated with lower risk of premature mortality. The lowest risk was found for those climbing 6–10 flights per day: 0.91; 95% confidence interval (CI): 0.85, 0.98, translated to approximately 44 to 55 days of additional survival. A similar pattern was found after applying propensity score matching and for cancer mortality (6–10 flights per day HR: 0.88; 95% CI: 0.80, 0.97), but not for CVD mortality (6–10 flights per day HR: 1.08; 95% CI: 0.91, 1.29). The association between stair climbing and lung cancer was similar to that of all-cause mortality. Conclusions: Climbing more than five flights of stairs at home per day was associated with a lower risk of all-cause and cancer mortality, but not CVD mortality, compared with those who did not take the stairs. The magnitude of the association was small and appeared susceptible to residual confounding. It is unlikely that at-home stair climbing is sufficient physical activity stimuli to lower the risk of premature mortality.

• Chiang, Cho-Han; Chiang, Cho-Hung; Pickering, John W; Stoyanov, Kiril M.; Chew,, Derek P. & Neumann, Johannes T. [Show all 38 contributors for this article] (2021). Performance of the European Society of Cardiology 0/1-Hour, 0/2-Hour, and 0/3-Hour Algorithms for Rapid Triage of Acute Myocardial Infarction. An International Collaborative Meta-analysis. Annals of Internal Medicine. ISSN 0003-4819. doi: 10.7326/M21-1499. Full text in Research Archive
• Kieffer, Sophie Kvalheim; Nauman, Javaid; Syverud, Kari; Selboskar, Hege; Lydersen, Stian & Ekelund, Ulf [Show all 7 contributors for this article] (2021). Association between Personal Activity Intelligence (PAI) and body weight in a population free from cardiovascular disease - The HUNT study. The Lancet Regional Health - Europe. 5. doi: 10.1016/j.lanepe.2021.100091. Full text in Research Archive Show summary

  Background: Personal Activity Intelligence (PAI) is a new metric for physical activity tracking, and is associated with reduced risk of all-cause and cardiovascular mortality. We prospectively investigated whether PAI is associated with lower body weight gain in a healthy population. Methods: We included 85,243 participants (40,037 men and 45,206 women) who participated in at least one of three waves of the Trøndelag Health Study (HUNT1: 1984-86, HUNT2: 1995-97, and HUNT3: 2006-08). We used questionnaires to estimate PAI, and linear mixed models to examine body weight according to PAI levels at three study waves. We also conducted regression analyses to assess separate relationships between change in PAI and the combined changes in PAI and physical activity recommendations, according to body weight from HUNT1 to HUNT3. Findings: Compared with HUNT1, body weight was 8.6 and 6.7 kg higher at HUNT3 for men and women, respectively, but was lower among those with ≥200 PAI at HUNT3. For both sexes, a change from inactive (0 PAI) at HUNT1 to ≥100 weekly PAI-score at HUNT2 and HUNT3, and a ≥100 PAI-score at all three occasions were associated with lower body weight gain, compared with the reference group (0 PAI at all three waves). Importantly, among both sexes, obtaining ≥100 weekly PAI at HUNT1 and HUNT3 was associated with lower body weight gain regardless of adhering to physical activity guidelines. Interpretation: Adhering to a high PAI over time may be a useful tool to attenuate excessive body weight gain in a population free from cardiovascular disease.

• Leppänen, Marja H.; Haapala, Eero A.; Väistö, Juuso; Ekelund, Ulf; Brage, Søren & Kilpeläinen, Tuomas O. [Show all 7 contributors for this article] (2021). Longitudinal and cross-sectional associations of adherence to 24-hour movement guidelines with cardiometabolic risk. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 32(1), p. 255–266. doi: 10.1111/sms.14081. Full text in Research Archive Show summary

  This study aimed to examine (1) adherence to 24 h movement guidelines over a 2 years follow-up in children aged 6–8 years and (2) association of this adherence with cardiometabolic risk factors. Physical activity and sleep were assessed by a monitor combining heart rate and accelerometry measurements. Screen time was reported by the parents. Body fat percentage, waist circumference, blood glucose, serum insulin, plasma lipids, and blood pressure were assessed, and a cardiometabolic risk score was calculated using z-scores. Children were classified as meeting the guidelines if they had on average ≥60 min/day of moderate-to-vigorous physical activity during the valid days; ≤120 min/day of screen time; and 9–11 h/day of sleep. In total, 485 children had valid data at baseline or at 2 years follow-up. Analyses were conducted using adjusted logistic and linear regression models. Most children adhered to the 24 h movement guidelines at baseline, but the adherence decreased over the 2 years follow-up. Meeting physical activity guidelines individually, or in combination with screen time and/or sleep, was longitudinally associated with a lower cardiometabolic risk score, insulin and waist circumference, and cross-sectionally additionally with lower diastolic blood pressure and higher high-density lipoprotein cholesterol. However, these associations became statistically non-significant after adjustment for body fat. In conclusion, meeting 24 h movement guidelines at baseline increases the odds of meeting them at 2 years follow-up in school-aged children. Furthermore, meeting 24 h movement guidelines is associated with lower levels of cardiometabolic risk factors, but these associations are partly explained by lower body fat. Thus, promoting movement behaviors, especially physical activity, and healthy weight in early childhood is important in supporting cardiometabolic health in children.

• Mielke, Gregore I.; Menezes, Ana Maria B.; Silva, Bruna Gonçalves Cordeiro da; Ekelund, Ulf; Crochemore-Silva, Inacio & Wehrmeister, Fernando César [Show all 8 contributors for this article] (2021). Associations between Device-measured Physical Activity and Cardiometabolic Health in the Transition to Early Adulthood. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 53(10), p. 2076–2085. doi: 10.1249/MSS.0000000000002696. Full text in Research Archive Show summary

  Purposes: The aims of this study were to investigate the cross-sectional and prospective associations between accelerometer-measured physical activity and cardiometabolic health in the transition to adulthood. Methods: Data from the 1993 Pelotas (Brazil) Birth Cohort were analyzed (n = 2280). Moderate-to-vigorous intensity physical activity (MVPA) (measured using a triaxial accelerometer) and cardiometabolic health (total fat mass, blood glucose, non-high-density lipoprotein cholesterol, triglycerides, and mean resting blood pressure) were examined at age 18 and 22 yr. Results: Overall, inverse dose–response associations between MVPA and cardiometabolic health at age 18 and 22 yr were observed in cross-sectional analyses of data from men and women. Prospective analyses showed that, in general, MVPA declined, and cardiometabolic health worsened in this 4-yr period in both men and women. Cardiometabolic health at age 22 yr reflected both MVPA at age 18 yr (β, −0.007; 95% confidence interval [CI], −0.014 to 0.000) and changes in MVPA from 18 to 22 yr (β, −0.030; 95% CI, −0.043 to −0.016) in men, but only changes in MVPA in women (β, −0.035; 95% CI, −0.058 to −0.011). In analyses of change over time, men who improved MVPA by 20 to 30 min·d−1 showed significant improvements in cardiometabolic health over 4 yr. The magnitude of association was slightly stronger for MVPA in 10-min bouts than for MVPA accumulated in bouts of 1 min, especially in women. Conclusions: Moderate-to-vigorous intensity physical activity is an important predictor of cardiometabolic health in early adulthood. Strategies to prevent declines in MVPA at this life stage are required to prevent deteriorating cardiometabolic health profiles.

• Collings, Paul J.; Grøntved, Anders; Jago, Russell; Kriemler, Susi; Northstone, Kate & Puder, Jardena J. [Show all 13 contributors for this article] (2021). Cross-sectional and prospective associations of sleep duration and bedtimes with adiposity and obesity risk in 15 810 youth from 11 international cohorts. Pediatric Obesity. ISSN 2047-6302. doi: 10.1111/ijpo.12873. Full text in Research Archive Show summary

  Objectives: To investigate associations of bedtimes and sleep durations with adiposity levels in children and adolescents. Methods: Individual data were pooled for 12 247 children (5819 with follow-up adiposity at 2.3 ± 1.4 years post-baseline) and 3563 adolescents from 11 international studies. Associations between questionnaire-based sleep durations, bedtimes and four groups of combined bedtimes and sleep lengths (later-shorter [reference]/earlier-shorter/later-longer/earlier-longer) with measured adiposity (body mass index [BMI] and waist circumference z-scores) and weight status, were investigated. Results: In children, longer sleep durations were consistently associated with lower adiposity markers, and earlier bedtimes were related to lower BMI z-score. Compared to sleeping <10 h, longer baseline sleep duration favourably predicted Δwaist z-score in girls (≥10 and <11 h (β-coefficient (95% confidence interval [CI])): −0.06 (−0.12 to −0.01)) and boys (≥11 h: −0.10 [−0.18 to −0.01]). Combined groups that were defined by longer sleep (later-longer and earlier-longer sleep patterns) were associated with lower adiposity, and later-longer sleep favourably predicted Δwaist z-score in girls (−0.09 [−0.15 to −0.02]). In adolescents, longer sleep durations and earlier bedtimes were associated with lower BMI z-score in the whole sample, and also with lower waist z-score in boys. Combined groups that were characterized by earlier bedtimes were associated with the same outcomes. For example, earlier-shorter (−0.22 (−0.43 to −0.01) and earlier-longer (−0.16 (−0.25 to −0.06) sleep were both associated with lower BMI z-score. Conclusions: If the associations are causal, longer sleep duration and earlier bedtimes should be targeted for obesity prevention, emphasizing longer sleep for children and earlier bedtimes for adolescents.

• Tarp, Jakob; Fagerland, Morten Wang; Dalene, Knut Eirik; Steene-Johannessen, Jostein; Hansen, Bjørge Hermann & Jefferis, Barbara [Show all 24 contributors for this article] (2021). Device-measured physical activity, adiposity and mortality: a harmonised meta-analysis of eight prospective cohort studies. British Journal of Sports Medicine. ISSN 0306-3674. 56(13), p. 725–732. doi: 10.1136/bjsports-2021-104827. Full text in Research Archive Show summary

  Background: The joint associations of total and intensity-specific physical activity with obesity in relation to all-cause mortality risk are unclear. Methods: We included 34 492 adults (72% women, median age 62.1 years, 2034 deaths during follow-up) in a harmonised meta-analysis of eight population-based prospective cohort studies with mean follow-up ranging from 6.0 to 14.5 years. Standard body mass index categories were cross-classified with sample tertiles of device-measured total, light-to-vigorous and moderate-to-vigorous physical activity and sedentary time. In five cohorts with waist circumference available, high and low waist circumference was combined with tertiles of moderate-to-vigorous physical activity. Results: There was an inverse dose–response relationship between higher levels of total and intensity-specific physical activity and mortality risk in those who were normal weight and overweight. In individuals with obesity, the inverse dose–response relationship was only observed for total physical activity. Similarly, lower levels of sedentary time were associated with lower mortality risk in normal weight and overweight individuals but there was no association between sedentary time and risk of mortality in those who were obese. Compared with the obese-low total physical activity reference, the HRs were 0.59 (95% CI 0.44 to 0.79) for normal weight-high total activity and 0.67 (95% CI 0.48 to 0.94) for obese-high total activity. In contrast, normal weight-low total physical activity was associated with a higher risk of mortality compared with the obese-low total physical activity reference (1.28; 95% CI 0.99 to 1.67). Conclusions: Higher levels of physical activity were associated with lower risk of mortality irrespective of weight status. Compared with obesity-low physical activity, there was no survival benefit of being normal weight if physical activity levels were low.

• Pontzer, Herman; Yamada, Yosuke; Sagayama, Hiroyuki; Ainslie, Philip N.; Andersen, Lene Frost & Anderson, Liam J. [Show all 82 contributors for this article] (2021). Daily energy expenditure through the human life course. Science. ISSN 0036-8075. 373(6556), p. 808–812. doi: 10.1126/science.abe5017. Full text in Research Archive Show summary

  Total daily energy expenditure (“total expenditure”) reflects daily energy needs and is a critical variable in human health and physiology, but its trajectory over the life course is poorly studied. We analyzed a large, diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 years. Total expenditure increased with fat-free mass in a power-law manner, with four distinct life stages. Fat-free mass–adjusted expenditure accelerates rapidly in neonates to ~50% above adult values at ~1 year; declines slowly to adult levels by ~20 years; remains stable in adulthood (20 to 60 years), even during pregnancy; then declines in older adults. These changes shed light on human development and aging and should help shape nutrition and health strategies across the life span.

• Zhou, Bin; Carrillo-Larco, Rodrigo M.; Danaei, Goodarz; Riley, Leanne M.; Paciorek, Christopher J. & Stevens, Gretchen A. [Show all 100 contributors for this article] (2021). Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants. The Lancet. ISSN 0140-6736. 398(10304), p. 957–980. doi: 10.1016/S0140-6736(21)01330-1. Full text in Research Archive Show summary

  Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. Findings The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. Interpretation Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings. Funding WHO.

• Speakman, John R.; Yamada, Yosuke; Sagayama, Hiroyuki; Berman, Elena S.F.; Ainslie, Philip N. & Andersen, Lene Frost [Show all 87 contributors for this article] (2021). A standard calculation methodology for human doubly labeled water studies. Cell Reports Medicine. 2(2). doi: 10.1016/j.xcrm.2021.100203. Full text in Research Archive Show summary

  The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass between 0 and 10 kg. Using this relationship to predict DSR from weight provides an equation for rCO2 over this size range that agrees well with indirect calorimetry (average difference 0.64%; SD = 12.2%). We propose adoption of these equations in future studies. Highlights • 5,756 doubly labeled water (DLW) measures highlight variation from calculation equation • We derive here new equations for calculating CO2 production when using DLW • These equations outperform previous equations in validation studies • We recommend these equations should be adopted in future studies using DLW in humans

• Andreassen, Silje Malen; Ekelund, Ulf & Bernhardsen, Guro Pauck (2021). No association between maternal exercise during pregnancy and the child’s weight status at age 7 years: The MoBa study. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 31(10), p. 1991–2001. doi: 10.1111/sms.14015. Full text in Research Archive Show summary

  Introduction: Maternal lifestyle during pregnancy may affect the development of overweight and obesity in the child. We examined whether maternal exercise during pregnancy is associated with offspring overweight and obesity in childhood. A secondary aim was to examine whether the association is affected by the child's physical activity level. Materials and methods: This study is based on data from the Norwegian Mother, Father and Child Cohort Study (MoBa), including 44 352 pregnancies and children (n = 32 304 in week 17 and n = 32 419 in week 30 in the final adjusted model). Maternal exercise during pregnancy was self-reported in gestational weeks 17 and 30. We conducted linear and logistic regression separately for girls and boys, and outcomes were the child's body mass index (BMI) and weight status (overweight/obese) at age 7 years. We further examined the additive joint association between maternal exercise during pregnancy and the child's leisure time physical activity on weight status at age 7 years. Results: In total, 12.4% of the children were classified as overweight or obese, and 1.7% as obese. The results suggest no association between maternal exercise in both gestational weeks 17 and 30 and the weight status of the child at age 7 years. The association between maternal exercise and the child's weight status at age 7 years appears not to be affected by the child's physical activity level. Conclusion: Maternal exercise level during pregnancy does not appear to be associated with the child's BMI or odds of being overweight or obese in childhood.

• Lee, Seung Won; Lee, Jinhee; Moon, Sung Yong; Jin, Hyun Young; Yang, Jee Myung & Ogino, Shuji [Show all 25 contributors for this article] (2021). Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: A nationwide cohort study. British Journal of Sports Medicine. ISSN 0306-3674. doi: 10.1136/bjsports-2021-104203. Full text in Research Archive Show summary

  Purpose: To determine the potential associations between physical activity and risk of SARS-CoV-2 infection, severe illness from COVID-19 and COVID-19 related death using a nationwide cohort from South Korea. Methods: Data regarding 212 768 Korean adults (age ≥20 years), who tested for SARS-CoV-2, from 1 January 2020 to 30 May 2020, were obtained from the National Health Insurance Service of South Korea and further linked with the national general health examination from 1 January 2018 to 31 December 2019 to assess physical activity levels. SARS-CoV-2 positivity, severe COVID-19 illness and COVID-19 related death were the main outcomes. The observation period was between 1 January 2020 and 31 July 2020. Results: Out of 76 395 participants who completed the general health examination and were tested for SARS-CoV-2, 2295 (3.0%) were positive for SARS-CoV-2, 446 (0.58%) had severe illness from COVID-19 and 45 (0.059%) died from COVID-19. Adults who engaged in both aerobic and muscle strengthening activities according to the 2018 physical activity guidelines had a lower risk of SARS-CoV-2 infection (2.6% vs 3.1%; adjusted relative risk (aRR), 0.85; 95% CI 0.72 to 0.96), severe COVID-19 illness (0.35% vs 0.66%; aRR 0.42; 95% CI 0.19 to 0.91) and COVID-19 related death (0.02% vs 0.08%; aRR 0.24; 95% CI 0.05 to 0.99) than those who engaged in insufficient aerobic and muscle strengthening activities. Furthermore, the recommended range of metabolic equivalent task (MET; 500–1000 MET min/week) was associated with the maximum beneficial effect size for reduced risk of SARS-CoV-2 infection (aRR 0.78; 95% CI 0.66 to 0.92), severe COVID-19 illness (aRR 0.62; 95% CI 0.43 to 0.90) and COVID-19 related death (aRR 0.17; 95% CI 0.07 to 0.98). Similar patterns of association were observed in different sensitivity analyses. Conclusion: Adults who engaged in the recommended levels of physical activity were associated with a decreased likelihood of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related death. Our findings suggest that engaging in physical activity has substantial public health value and demonstrates potential benefits to combat COVID-19.

• Dalene, Knut Eirik; Tarp, Jakob; Selmer, Randi Marie; Ariansen, Inger Kristine Holtermann; Nystad, Wenche & Coenen, Pieter [Show all 9 contributors for this article] (2021). Occupational physical activity and longevity in working men and women in Norway: a prospective cohort study. The Lancet Public Health. ISSN 2468-2667. 6(6), p. e386–e395. doi: 10.1016/S2468-2667(21)00032-3. Full text in Research Archive Show summary

  Background: Studies suggest that high occupational physical activity increases mortality risk. However, it is unclear whether this association is causal or can be explained by a complex network of socioeconomic and behavioural factors. We aimed to examine the association between occupational physical activity and longevity, taking a complex network of confounding variables into account. Methods: In this prospective cohort study, we linked data from Norwegian population-based health examination surveys, covering all parts of Norway with data from the National Population and Housing Censuses and the Norwegian Cause of Death Registry. 437 378 participants (aged 18–65 years; 48·7% men) self-reported occupational physical activity (mutually exclusive groups: sedentary, walking, walking and lifting, and heavy labour) and were followed up from study entry (between February, 1974, and November, 2002) to death or end of follow-up on Dec 31, 2018, whichever came first. We estimated differences in survival time (death from all causes, cardiovascular disease, and cancer) between occupational physical activity categories using flexible parametric survival models adjusted for confounding factors. Findings: During a median of 28 years (IQR 25–31) from study entry to the end of follow-up, 74 203 (17·0%) of the participants died (all-cause mortality), of which 20 111 (27·1%) of the deaths were due to cardiovascular disease and 29 886 (40·3%) were due to cancer. Crude modelling indicated shorter mean survival times among men in physically active occupations than in those with sedentary occupations. However, this finding was reversed following adjustment for confounding factors (birth cohort, education, income, ethnicity, prevalent cardiovascular disease, smoking, leisure-time physical activity, body-mass index), with estimates suggesting that men in occupations characterised by walking, walking and lifting, and heavy labour had life expectancies equivalent to 0·4 (95% CI −0·1 to 1·0), 0·8 (0·3 to 1·3), and 1·7 (1·2 to 2·3) years longer, respectively, than men in the sedentary referent category. Results for mortality from cardiovascular disease and cancer showed a similar pattern. No clear differences in survival times were observed between occupational physical activity groups in women. Interpretation: Our results suggest that moderate to high occupational physical activity contributes to longevity in men. However, occupational physical activity does not seem to affect longevity in women. These results might inform future physical activity guidelines for public health.

• Sluijs, Esther M.F. van; Ekelund, Ulf; Crochemore-Silva, Inacio; Guthold, Regina; Ha, Amy & Lubans, David [Show all 9 contributors for this article] (2021). Physical activity behaviours in adolescence: current evidence and opportunities for intervention. The Lancet. ISSN 0140-6736. 398(10298), p. 429–442. doi: 10.1016/S0140-6736(21)01259-9. Full text in Research Archive Show summary

  Young people aged 10–24 years constitute 24% of the world's population; investing in their health could yield a triple benefit—eg, today, into adulthood, and for the next generation. However, in physical activity research, this life stage is poorly understood, with the evidence dominated by research in younger adolescents (aged 10–14 years), school settings, and high-income countries. Globally, 80% of adolescents are insufficiently active, and many adolescents engage in 2 h or more daily recreational screen time. In this Series paper, we present the most up-to-date global evidence on adolescent physical activity and discuss directions for identifying potential solutions to enhance physical activity in the adolescent population. Adolescent physical inactivity probably contributes to key global health problems, including cardiometabolic and mental health disorders, but the evidence is methodologically weak. Evidence-based solutions focus on three key components of the adolescent physical activity system: supportive schools, the social and digital environment, and multipurpose urban environments. Despite an increasing volume of research focused on adolescents, there are still important knowledge gaps, and efforts to improve adolescent physical activity surveillance, research, intervention implementation, and policy development are urgently needed.

• Mañas, Asier; Pozo-Cruz, Borja del; Ekelund, Ulf; Reyna, José Losa; Gómez, Irene Rodríguez & Carreño, José Antonio Carnicero [Show all 9 contributors for this article] (2021). Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults: A prospective cohort study. Journal of Sport and Health Science. ISSN 2095-2546. doi: 10.1016/j.jshs.2021.05.004. Full text in Research Archive Show summary

  Purpose: To examine the associations of accelerometer-derived steps volume and intensity with hospitalizations and all-cause mortality in older adults. Methods: This prospective cohort study involved 768 community-dwelling Spanish older adults (78.8 ± 4.9 years, mean ± SD; 53.9% females) from the Toledo Study for Healthy Aging (2012–2017). The number of steps per day and step cadence (steps/min) were derived from a hip-mounted accelerometer worn for at least 4 days at baseline. Participants were followed-up over a mean period of 3.1 years for hospitalization and 5.7 years for all-cause mortality. Cox proportional hazards regression models were used to estimate the individual and joint associations between daily steps and stepping intensity with hospitalizations and all-cause mortality. Results: Included participants walked 5835 ± 3445 steps/day (mean ± SD) with an intensity of 7.3 ± 4.1 steps/min. After adjusting for age, sex, body mass index (BMI), education, income, marital status and comorbidities, higher step count (hazard ratio (HR) = 0.95, 95% confidence intervals (95%CI: 0.90–1.00, and HR = 0.87, 95%CI: 0.81–0.95 per additional 1000 steps) and higher step intensity (HR = 0.95, 95%CI: 0.91–0.99, and HR = 0.89, 95%CI: 0.84–0.95 per each additional step/min) were associated with fewer hospitalizations and all-cause mortality risk, respectively. Compared to the group having low step volume and intensity, individuals in the group having high step volume and intensity had a lower risk of hospitalization (HR = 0.72, 95%CI: 0.52–0.98) and all-cause mortality (HR = 0.60, 95%CI: 0.37–0.98). Conclusion: Among older adults, both high step volume and step intensity were significantly associated with lower hospitalization and all-cause mortality risk. Increasing step volume and intensity may benefit older people.

• Solberg, Runar Barstad; Steene-Johannessen, Jostein; Anderssen, Sigmund Alfred; Ekelund, Ulf; Säfvenbom, Reidar & Haugen, Tommy [Show all 11 contributors for this article] (2021). Effects of a school-based physical activity intervention on academic performance in 14-year old adolescents: a cluster randomized controlled trial – the School in Motion study. BMC Public Health. 21. doi: 10.1186/s12889-021-10901-x. Full text in Research Archive Show summary

  Background: School-based physical activity interventions evaluating the effect on academic performance usually includes children. We aimed to investigate the effect of a nine-month, school-based physical activity intervention titled School in Motion (ScIM) on academic performance in adolescents. Methods: Thirty secondary schools in Norway were cluster-randomized into three groups: the Physically active learning (PAL) group (n = 10), the Don’t worry – Be Happy (DWBH) group (n = 10) or control (n = 10). Target dose in both intervention groups was 120 min/week of additional PA during school hours. Parental consent was obtained from 2084 adolescent students (76%). Standardized national tests in reading and numeracy was conducted at baseline and at the end of the intervention. We used linear mixed model to test intervention effects. We found significant intervention effects in numeracy and reading among students in both interventions when compared with controls. Results: The mean difference in change in numeracy was 1.7 (95% CI: 0.9 to 2.5; Cohen’s d = 0.12) and 2.0 (95% CI: 1.4 to 2.7; Cohen’s d = 0.23) points in favour of students in the PAL and DWBH intervention, respectively. Similar results were found for reading, where the mean difference in change was 0.9 (95% CI 0.2 to 1.6; Cohen’s d = 0.06) and 1.1 (95% CI 0.3 to 1.9; Cohen’s d = 0.18) points in favour of students in the PAL and DWBH intervention, respectively. When conducting intention to treat analysis with imputed data the estimates were attenuated and some no longer significant. Conclusion: The ScIM study demonstrates that two different school-based PA interventions providing approximately 120 min of additional PA weekly over nine months, significantly improved numeracy and reading performance in 14-year old students compared with controls. However, the results should be interpreted with caution as the effect sizes reported were very small or small and the estimates were attenuated when conducting intention to treat analysis. Despite this, our results are still positive and suggest that PA interventions are viable models to increase academic performance among adolescents.

• Chastin, Sebastien F.M.; McGregor, Duncan E.; Biddle, Stuart J.H.; Cardon, Greet; Chaput, Jean-Philippe & Dall, Philippa M. [Show all 13 contributors for this article] (2021). Striking the right balance: Evidence to inform combined physical activity and sedentary behavior recommendations. Journal of Physical Activity and Health. ISSN 1543-3080. 18(6), p. 631–637. doi: 10.1123/jpah.2020-0635. Full text in Research Archive Show summary

  Background: Crucial evidence gaps regarding: (1) the joint association of physical activity and sedentary time with health outcomes and (2) the benefits of light-intensity physical activity were identified during the development of recommendations for the World Health Organization Guidelines on physical activity and sedentary behavior (SB). The authors present alternative ways to evidence the relationship between health outcomes and time spent in physical activity and SB and examine how this could be translated into a combined recommendation in future guidelines. Methods: We used compositional data analysis to quantify the dose–response associations between the balance of time spent in physical activity and SB with all-cause mortality. The authors applied this approach using 2005–2006 National Health and Nutrition Examination Survey accelerometer data. Results: Different combinations of time spent in moderate- to vigorous-intensity physical activity, light-intensity physical activity, and SB are associated with similar all-cause mortality risk level. A balance of more than 2.5 minutes of moderate- to vigorous-intensity physical activity per hour of daily sedentary time is associated with the same magnitude of risk reduction for all-cause mortality as obtained by being physically active according to the current recommendations. Conclusion: This method could be applied to provide evidence for more flexible recommendations in the future with options to act on different behaviors depending on individuals’ circumstances and capacity.

• Sagelv, Edvard Hamnvik; Ekelund, Ulf; Hopstock, Laila Arnesdatter; Fimland, Marius Steiro; Løvsletten, Ola & Wilsgaard, Tom [Show all 7 contributors for this article] (2021). The bidirectional associations between leisure time physical activity change and body mass index gain. The Tromsø Study 1974–2016. International Journal of Obesity. ISSN 0307-0565. 45(8), p. 1830–1843. doi: 10.1038/s41366-021-00853-y. Full text in Research Archive Show summary

  Objectives To examine whether leisure time physical activity changes predict subsequent body mass index (BMI) changes, and conversely, whether BMI changes predict subsequent leisure time physical activity changes. Methods: This prospective cohort study included adults attending ≥3 consecutive Tromsø Study surveys (time: T1, T2, T3) during 1974–2016 (n = 10779). If participants attended >3 surveys, we used the three most recent surveys. We computed physical activity change (assessed by the Saltin-Grimby Physical Activity Level Scale) from T1 to T2, categorized as Persistently Inactive (n = 992), Persistently Active (n = 7314), Active to Inactive (n = 1167) and Inactive to Active (n = 1306). We computed BMI change from T2 to T3, which regressed on preceding physical activity changes using analyses of covariance. The reverse association (BMI change from T1 to T2 and physical activity change from T2 to T3; n = 4385) was assessed using multinomial regression. Results: Average BMI increase was 0.86 kg/m2 (95% CI: 0.82–0.90) from T2 to T3. With adjustment for sex, birth year, education, smoking and BMI at T2, there was no association between physical activity change from T1 to T2 and BMI change from T2 to T3 (Persistently Inactive: 0.89 kg/m2 (95% CI: 0.77–1.00), Persistently Active: 0.85 kg/m2 (95% CI: 0.81–0.89), Active to Inactive: 0.90 kg/m2 (95% CI: 0.79–1.00), Inactive to Active 0.85 kg/m2 (95% CI: 0.75–0.95), p = 0.84). Conversely, increasing BMI was associated with Persistently Inactive (odds ratio (OR): 1.17, 95% CI: 1.08–1.27, p < 0.001) and changing from Active to Inactive (OR: 1.16, 95% CI: 1.07–1.25, p < 0.001) compared with being Persistently Active. Conclusions: We found no association between leisure time physical activity changes and subsequent BMI changes, whereas BMI change predicted subsequent physical activity change. These findings indicate that BMI change predicts subsequent physical activity change at population level and not vice versa.

• Korhonen, Marika; Väistö, Juuso; Veijalainen, Aapo; Leppänen, Marja H.; Ekelund, Ulf & Laukkanen, Jari A. [Show all 10 contributors for this article] (2021). Longitudinal associations of physical activity, sedentary time, and cardiorespiratory fitness with arterial health in children–the PANIC study. Journal of Sports Sciences. ISSN 0264-0414. 39(17), p. 1980–1987. doi: 10.1080/02640414.2021.1912450. Full text in Research Archive Show summary

  We investigated the longitudinal associations of physical activity (PA), sedentary time (ST), and cardiorespiratory fitness (CRF) with arterial health among children. In our primary analyses, we investigated 245 children (girls 51.8%) aged 6-9 years participating in the baseline examinations who had data on arterial health at 2-year follow-up. We also utilized a subsample of 90 children who had a complete arterial health data at baseline and 2-year follow-up. ST (≤1.5 METs), light PA (>1.5-4 METs), moderate PA (>4-7 METs), vigorous PA (>7METs), and moderate-to-vigorous PA (MVPA, >4 METs) were assessed by combined movement and heart rate monitoring and CRF by maximal exercise testing on a cycle ergometer at baseline and 2-year follow-up. Stiffness index (SI) as a measure of arterial stiffness and change in reflection index during exercise test (DRI) as a measure of arterial dilation capacity were assessed by pulse contour analysis. Two-year change in vigorous PA was associated with DRI in boys but not in girls (p=0.021 for interaction). In a subsample analyses, 2-year changes in MPA, VPA, and MVPA were inversely associated with 2-year change in SI. In conclusion, promoting PA at higher intensities may confer larger benefits on arterial health than reducing ST and increasing LPA.

• Steene-Johannessen, Jostein; Anderssen, Sigmund Alfred; Kolle, Elin; Hansen, Bjørge Hermann; Bratteteig, Mari & Dalhaug, Emilie Frederikke Mass [Show all 10 contributors for this article] (2021). Temporal trends in physical activity levels across more than a decade – a national physical activity surveillance system among Norwegian children and adolescents. International Journal of Behavioral Nutrition and Physical Activity. 18. doi: 10.1186/s12966-021-01120-z. Full text in Research Archive Show summary

  Background: There is a scarcity of device measured data on temporal changes in physical activity (PA) in large population-based samples. The purpose of this study is to describe gender and age-group specific temporal trends in device measured PA between 2005, 2011 and 2018 by comparing three nationally representative samples of children and adolescents. Methods: Norwegian children and adolescents (6, 9 and 15-year-olds) were invited to participate in 2005 (only 9- and 15-year-olds), 2011 and 2018 through cluster sampling (schools primary sampling units). A combined sample of 9500 individuals participated. Physical activity was assessed by hip worn accelerometers, with PA indices including overall PA (counts per minute), moderate-to-vigorous intensity PA (MVPA), and PA guideline adherence (achieving on average ≥ 60 min/day of moderate-to-vigorous PA). Random-effects linear regressions and logistic regressions adjusted for school-level clusters were used to analyse temporal trends. Findings: In total, 8186 of the participating children and adolescents provided valid PA data. Proportions of sufficiently active 6-year-olds were almost identical in 2011 and 2018; boys 95% (95% CI: 92, 97) and 94% (95%CI: 92, 96) and girls 86% (95% CI: 83, 90) and 86% (95% CI: 82, 90). Proportions of sufficiently active 15-year-olds in 2005 and 2018 were 52% (95% CI: 46, 59) and 55% (95% CI: 48, 62) in boys, and 48% (95% CI: 42, 55) and 44% (95% CI: 37, 51) in girls, respectively, resulting from small differences in min/day of MVPA. Among 9-year-old boys and girls, proportions of sufficiently active declined between 2005 and 2018, from 90% (95% CI: 87, 93) to 84% (95% CI: 80, 87)) and 74% (95% CI: 69, 79) to 68% (95% CI: 64, 72), respectively. This resulted from 9.7 min/day less MVPA in boys (95% CI: − 14.8, − 4.7; p < 0.001) and 3.2 min/day less MVPA (95% CI: − 7.0, 0.7; p = 0.106) in girls. Conclusions: PA levels have been fairly stable between 2005, 2011 and 2018 in Norwegian youth. However, the declining PA level among 9-year-old boys and the low proportion of 15-year-olds sufficiently active is concerning. To evaluate the effect of, and plan for new, PA promoting strategies, it is important to ensure more frequent, systematic, device-based monitoring of population-levels of PA.

• Haapala, Eero A.; Väistö, Juuso; Ihalainen, Johanna K.; González, Claudia Tomaselli; Leppänen, Marja H. & Veijalainen, Aapo [Show all 13 contributors for this article] (2021). Associations of physical activity, sedentary time, and diet quality with biomarkers of inflammation in children. European Journal of Sport Science (EJSS). ISSN 1746-1391. doi: 10.1080/17461391.2021.1892830. Full text in Research Archive Show summary

  We investigated the associations of physical activity (PA), sedentary time (ST), and diet quality with biomarkers of inflammation in 390 children (192 girls, 198 boys) aged 6–8 years. PA energy expenditure (PAEE), light PA, moderate PA (MPA), vigorous PA (VPA), moderate-to-vigorous PA (MVPA), and ST were assessed by combined movement and heart rate sensor. Finnish Children Healthy Eating Index was calculated using data from 4 d food records. Body fat percentage (BF%) was measured by dual-energy X-ray absorptiometry. High-sensitivity C-reactive protein (Hs-CRP), leptin, interleukin-6 (IL-6), adiponectin, tumour necrosis factor-α, and glycoprotein acetyls were measured from fasting blood samples. PAEE, MPA, VPA, and MVPA were inversely associated with hs-CRP (β=−191 to −139, 95% CI=−0.294 to −0.024), leptin (β=−0.409 to −0.301, 95% CI=−0.499 to −0.107), IL-6 (β=−0.136 to −0.104, 95% CI=−0.240 to −0.001) and PAEE, MPA, and MVPA were inversely associated with glycoprotein acetyls (β=−0.117 to −0.103, 95% CI=−0.213 to −0.001). ST was directly associated with hs-CRP (β=0.170, 95% CI=0.070–0.269), leptin (β=0.355, 95% CI=0.265–0.445), and IL-6 (β=0.105, 95% CI=0.005–0.205). VPA was inversely associated with hs-CRP, leptin, and IL-6 in children with higher BF% (β=−0.344 to −0.181, 95% CI=−0.477 to −0.033) but not among children with lower BF% (β=−0.007–0.033, 95% CI=−0.183–0.184). In conclusion, PA was inversely and ST directly associated with circulating levels of biomarkers of inflammation among children. Furthermore, we observed that PA was inversely associated with these biomarkers for inflammation in children with a higher BF%.

• Jones, Paul Remy; Rajalahti, Tarja; Resaland, Geir Kåre; Aadland, Eivind; Steene-Johannessen, Jostein & Anderssen, Sigmund Alfred [Show all 10 contributors for this article] (2021). Cross-sectional and prospective associations between aerobic fitness and lipoprotein particle profile in a cohort of Norwegian schoolchildren. Atherosclerosis. ISSN 0021-9150. 321, p. 21–29. doi: 10.1016/j.atherosclerosis.2021.02.002. Full text in Research Archive Show summary

  Background and aims The associations between aerobic fitness and traditional measures of lipid metabolism in children are uncertain. We investigated whether higher levels of aerobic fitness benefit lipoprotein metabolism by exploring associations with a comprehensive lipoprotein particle profile. Methods In our prospective cohort study, we used targeted proton nuclear magnetic resonance (1H NMR) spectroscopy to profile 57 measures of lipoprotein metabolism from fasting serum samples of 858 fifth-grade Norwegian schoolchildren (49.0% girls; mean age 10.0 years). Aerobic fitness was measured using an intermittent shuttle run aerobic fitness test. We used multiple linear regression adjusted for potential confounders to examine cross-sectional and prospective associations between aerobic fitness and lipoprotein particle profile. Results Higher levels of aerobic fitness were associated with a favourable lipoprotein particle profile in the cross-sectional analysis, which included inverse associations with all measures of very low-density lipoprotein (VLDL) particles (e.g., −0.06 mmol·L−1 or –0.23 SD units; 95% CI = −0.31, −0.16 for VLDL cholesterol concentration). In the prospective analysis, the favourable pattern of associations persisted, though the individual associations tended to be more consistent with those of the cross-sectional analysis for the VLDL subclass measures compared to the low-density lipoproteins and high-density lipoproteins. Adjustment for adiposity attenuated the associations in both cross-sectional and prospective models. Nevertheless, an independent effect of aerobic fitness remained for some measures. Conclusions Improving children's aerobic fitness levels should benefit lipoprotein metabolism, though a concomitant reduction in adiposity would likely potentiate this effect.

• Westerterp, Klaas R.; Yamada, Yosuke; Sagayama, Hiroyuki; Ainslie, Philip N.; Andersen, Lene F. & Anderson, Liam J. [Show all 82 contributors for this article] (2021). Physical activity and fat-free mass during growth and in later life. American Journal of Clinical Nutrition. ISSN 0002-9165. 114(5), p. 1583–1589. doi: 10.1093/ajcn/nqab260. Full text in Research Archive Show summary

  Background: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass. Objectives: A study is presented of the association between FFM and physical activity in relation to age. Methods: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3–96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution. Results: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males < 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM–adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: −0.2, 1.7 kg) and 1.0 kg (95% CI: −0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively. Conclusions: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults.

• Mühlen, Jan M.; Stang, Julie; Skovgaard, Esben Lykke; Júdice, Pedro B.; Molina-Garcia, Pablo & Johnston, William [Show all 15 contributors for this article] (2021). Recommendations for determining the validity of consumer wearable heart rate devices: Expert statement and checklist of the INTERLIVE Network. British Journal of Sports Medicine. ISSN 0306-3674. 55(14), p. 767–779. doi: 10.1136/bjsports-2020-103148. Full text in Research Archive Show summary

  Assessing vital signs such as heart rate (HR) by wearable devices in a lifestyle-related environment provides widespread opportunities for public health related research and applications. Commonly, consumer wearable devices assessing HR are based on photoplethysmography (PPG), where HR is determined by absorption and reflection of emitted light by the blood. However, methodological differences and shortcomings in the validation process hamper the comparability of the validity of various wearable devices assessing HR. Towards Intelligent Health and Well-Being: Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives towards developing best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice validation protocol for consumer wearables assessing HR by PPG. The recommendations were developed through the following multi-stage process: (1) a systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, (2) an unstructured review of the wider literature pertaining to factors that may introduce bias during the validation of these devices and (3) evidence-informed expert opinions of the INTERLIVE Network. A total of 44 articles were deemed eligible and retrieved through our systematic literature review. Based on these studies, a wider literature review and our evidence-informed expert opinions, we propose a validation framework with standardised recommendations using six domains: considerations for the target population, criterion measure, index measure, testing conditions, data processing and the statistical analysis. As such, this paper presents recommendations to standardise the validity testing and reporting of PPG-based HR wearables used by consumers. Moreover, checklists are provided to guide the validation protocol development and reporting. This will ensure that manufacturers, consumers, healthcare providers and researchers use wearables safely and to its full potential.

• Skrede, Turid; Aadland, Eivind; Anderssen, Sigmund Alfred; Resaland, Geir Kåre & Ekelund, Ulf (2021). Bi-directional prospective associations between sedentary time, physical activity and adiposity in 10-year old Norwegian children. Journal of Sports Sciences. ISSN 0264-0414. 39(15), p. 1772–1779. doi: 10.1080/02640414.2021.1898114. Full text in Research Archive Show summary

  There is an adverse cross-sectional association between sedentary time, physical activity (PA) and adiposity, but weak and inconsistent estimates raise question to the direction of associations. The present study aims to examine whether the prospective association between sedentary time, different PA intensities and indicators of adiposity is bi-directional. The Active Smarter Kids Study obtained data from 869 ten-year-old children with valid measurements for sedentary time, PA, and adiposity at baseline and follow-up. Time spent sedentary and PA was measured by accelerometry, adiposity was assessed by three different measures: body mass index (BMI), waist circumference (WC) and sum of four skinfolds (S4SF). Neither overall PA nor time spent sedentary predicted lower BMI or WC at follow-up, but the time spent in moderate-and-vigorous PA (MVPA) and vigorous PA (VPA) predicted lower S4SF at follow-up among boys (MVPA β − 0.066 [95% CI −0.105, −0.027] p = 0.001). Baseline BMI and WC predicted less overall PA, MVPA and VPA in boys. All adiposity measures predicted more time spent sedentary at follow-up in boys. The results suggest that overall PA and sedentary time do not predict future adiposity. Baseline adiposity may rather predict more sedentary time and less higher intensity activity.

• Steene-Johannessen, Jostein; Hansen, Bjørge Hermann; Dalene, Knut Eirik; Kolle, Elin; Northstone, Kate & Møller, Niels Christian [Show all 51 contributors for this article] (2020). Variations in accelerometry measured physical activity and sedentary time across Europe – harmonized analyses of 47,497 children and adolescents. International Journal of Behavioral Nutrition and Physical Activity. 17. doi: 10.1186/s12966-020-00930-x. Full text in Research Archive Show summary

  Background: Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe. Methods: Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2–18 years) from 18 different European countries. Results: Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age. Conclusions: Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

• Hall, Katherine S.; Hyde, Eric T.; Bassett, David R.; Carlson, Susan A.; Carnethon, Mercedes & Ekelund, Ulf [Show all 15 contributors for this article] (2020). Systematic review of the prospective association of daily step counts with risk of mortality, cardiovascular disease, and dysglycemia. International Journal of Behavioral Nutrition and Physical Activity. 17. doi: 10.1186/s12966-020-00978-9. Full text in Research Archive Show summary

  Background: Daily step counts is an intuitive metric that has demonstrated success in motivating physical activity in adults and may hold potential for future public health physical activity recommendations. This review seeks to clarify the pattern of the associations between daily steps and subsequent all-cause mortality, cardiovascular disease (CVD) morbidity and mortality, and dysglycemia, as well as the number of daily steps needed for health outcomes. Methods: A systematic review was conducted to identify prospective studies assessing daily step count measured by pedometer or accelerometer and their associations with all-cause mortality, CVD morbidity or mortality, and dysglycemia (dysglycemia or diabetes incidence, insulin sensitivity, fasting glucose, HbA1c). The search was performed across the Medline, Embase, CINAHL, and the Cochrane Library databases from inception to August 1, 2019. Eligibility criteria included longitudinal design with health outcomes assessed at baseline and subsequent timepoints; defining steps per day as the exposure; reporting all-cause mortality, CVD morbidity or mortality, and/or dysglycemia outcomes; adults ≥18 years old; and non-patient populations. Results: Seventeen prospective studies involving over 30,000 adults were identified. Five studies reported on all-cause mortality (follow-up time 4–10 years), four on cardiovascular risk or events (6 months to 6 years), and eight on dysglycemia outcomes (3 months to 5 years). For each 1000 daily step count increase at baseline, risk reductions in all-cause mortality (6–36%) and CVD (5–21%) at follow-up were estimated across a subsample of included studies. There was no evidence of significant interaction by age, sex, health conditions or behaviors (e.g., alcohol use, smoking status, diet) among studies that tested for interactions. Studies examining dysglycemia outcomes report inconsistent findings, partially due to heterogeneity across studies of glycemia-related biomarker outcomes, analytic approaches, and sample characteristics. Conclusions: Evidence from longitudinal data consistently demonstrated that walking an additional 1000 steps per day can help lower the risk of all-cause mortality, and CVD morbidity and mortality in adults, and that health benefits are present below 10,000 steps per day. However, the shape of the dose-response relation is not yet clear. Data are currently lacking to identify a specific minimum threshold of daily step counts needed to obtain overall health benefit.

• Bielemann, Renata M.; Silveira, Marysabel P. T.; Lutz, Bárbara H.; Miranda, Vanessa I. A.; Gonzalez, Maria Cristina & Brage, Soren [Show all 8 contributors for this article] (2020). Objectively Measured Physical Activity and Polypharmacy Among Brazilian Community-Dwelling Older Adults. Journal of Physical Activity and Health. ISSN 1543-3080. 17(7), p. 729–735. doi: 10.1123/jpah.2019-0461. Full text in Research Archive Show summary

  Background: Previous observations regarding association between physical activity (PA) and use of medicines among older adults are derived from self-reported PA. This study aimed to evaluate the association between objectively measured PA and polypharmacy among older adults with multimorbidity in Southern Brazil. Methods: This study included 875 noninstitutionalized older people, aged ≥60 years. Prescribed medicines used in the 15 days prior to the interview, socioeconomic data, and the presence of comorbidities were self-reported. Accelerometers were used to evaluate PA following the interview. Results: Prevalence of polypharmacy (≥5 medicines) was 38.3% (95% confidence interval, 35.0–41.5); those belonging to the lowest tertile of PA used more medicines. The authors observed a significant inverse association for polypharmacy between men belonging to the second and third tertiles of PA for objectively measured overall PA and light PA compared with the most inactive tertile. For women, the association between PA and polypharmacy was significant for overall, light, and moderate to vigorous PA only in the third tertile. Conclusions: Overall, light and moderate to vigorous PA were inversely associated to polypharmacy and differed by gender. Promotion of PA in older adults may be an effective intervention to reduce the number of medicines used independent of the number of comorbidities.

• Ricardo, Luiza Isnardi Cardoso; Wendt, Andrea; Galliano, Leony; Muller, Werner de Andrade; Cruz, Gloria Izabel Niño & Wehrmeister, Fernando [Show all 9 contributors for this article] (2020). Number of days required to estimate physical activity constructs objectively measured in different age groups: Findings from three Brazilian (Pelotas) population-based birth cohorts. PLOS ONE. 15(1). doi: 10.1371/journal.pone.0216017. Full text in Research Archive Show summary

  Purpose: The present study aims to estimate the minimum number of accelerometer measurement days needed to estimate habitual physical activity (PA) among 6- (2010), 18- (2011) and 30- (2012) year-old participants, belonging to three population-based Brazilian birth cohorts. Method: PA was assessed by triaxial wrist-worn GENEActiv accelerometers and the present analysis is restricted to participants with at least 6 consecutive days of measurement. Accelerometer raw data were analyzed with R-package GGIR. Description of PA measures (overall PA, moderate-to-vigorous PA (MVPA), light PA (LPA)) on weekdays and weekend days were conducted, and statistical differences were tested with chi-squared and Kruskal-Wallis tests. Spearman Brown Formulae was applied to test reliability of different number of days of accelerometer use. Results: Differences between week and weekend days regarding LPA, MVPA and overall PA, were only observed among 30-year-olds. Higher levels of MVPA (p = 0.006) and overall PA (p<0.001) were identified on weekdays. For overall PA, to achieve a reliability coefficient >0.70, two and three days of measurement were needed in adults and children, respectively. For LPA, a reliability coefficient >0.70 was achieved with five days in 6-year-old children, three days in 18-year-old young adults, and four days in 30-year-old adults. Considering MVPA, four days would be necessary to represent a week of measurement among all cohort groups. Conclusion: Our results show that four and five measurement days are needed to estimate all habitual PA constructs, for children and adults, respectively. Also, among 30-year-old adults, it is important to make efforts towards weekend days measurement.

• Kallio, Jouni; Hakonen, Harto; Syväoja, Heidi; Kulmala, Janne; Kankaanpää, Anna & Ekelund, Ulf [Show all 7 contributors for this article] (2020). Changes in physical activity and sedentary time during adolescence: Gender differences during weekdays and weekend days. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(7), p. 1265–1275. doi: 10.1111/sms.13668. Full text in Research Archive Show summary

  Objectives: The objective of this study was to determine the gender‐specific and time‐segmented changes in accelerometer measured physical activity (PA) and sedentary time (ST) during adolescence. Methods: The study population (N = 970) consisted of children from nine schools throughout Finland. At the baseline, the children were in grades 4‐7 (ages 10‐13). Five times during the two‐year follow‐up period, hip‐worn accelerometers (ActiGraph GT3X+) were deployed for seven consecutive days in order to monitor the pupils’ PA. The daily time spent in vigorous (VPA), moderate to vigorous (MVPA), and light physical activity(LPA), as well as sedentary time(ST), were assessed. Results: Significant gender differences were observed in terms of the changes in MVPA and ST during the follow‐up period. The total MVPA declined significantly in boys (by 2.2min/day/year from 60 min/d at baseline) but not in girls (49 min/d at baseline). The total ST increased both in boys (by 20.7%‐points/y) and in girls (by 16.1%‐points/y, P < .001). However, when we compared the results during the weekdays and weekend days separately, we observed that the declines in MVPA and increases in ST were greater in boys than in girls during the weekend days. Conclusion: A greater decrease in PA and a greater increase in ST during adolescence were observed among boys than among girls, especially during weekend days. In order to diminish these unfavorable behavioral changes during adolescence, we encourage the separate tailoring of interventions for boys and girls and for weekdays and weekends.

• Taddei, Cristina; Jackson, Rod; Zhou, Bin; Bixby, Honor; Danaei, Goodarz & Cesare, Mariachiara Di [Show all 361 contributors for this article] (2020). National trends in total cholesterol obscure heterogeneous changes in HDL and non-HDL cholesterol and total-to-HDL cholesterol ratio: A pooled analysis of 458 population-based studies in Asian and Western countries. International Journal of Epidemiology. ISSN 0300-5771. 49(1), p. 173–192. doi: 10.1093/ije/dyz099. Full text in Research Archive
• Husøy, Anders; Dalene, Knut Eirik; Steene-Johannessen, Jostein; Anderssen, Sigmund Alfred; Ekelund, Ulf & Tarp, Jakob (2020). Effect modification by cardiorespiratory fitness on the association between physical activity and cardiometabolic health in youth: A systematic review. Journal of Sports Sciences. ISSN 0264-0414. doi: 10.1080/02640414.2020.1847919. Full text in Research Archive Show summary

  Physical activity and cardiorespiratory fitness are inversely associated with markers of cardiometabolic risk in children and adolescents, but the interplay between these variables in relation to the cardiometabolic risk profile is unclear. We systematically reviewed the literature to examine whether the association between physical activity and cardiometabolic health differs by levels of cardiorespiratory fitness in youth. A literature search was conducted in PubMed and EMBASE, filtered from 2001 up until July 2019. We obtained 8980 citations, with 6915 remaining after removal of duplicates. Estimates were retrieved from 18 studies. All included articles went through a risk of bias assessment. We found that 14 out of 20 (70%) effect-estimates supported stronger associations between physical activity and cardiometabolic health markers among low-fit youth as compared to their high-fit peers. The most consistent findings were observed with biochemical markers and blood pressure as outcomes. However, substantial uncertainty is associated with these findings as most of the included studies (~72%) had a high risk of bias. More than two-thirds of the findings supported greatest benefits of physical activity on cardiometabolic risk markers in youth with low cardiorespiratory fitness, although the clinical importance of this difference is unclear.

• Tarp, Jakob; Hansen, Bjørge Hermann; Fagerland, Morten; Steene-Johannessen, Jostein; Anderssen, Sigmund Alfred & Ekelund, Ulf (2020). Accelerometer-measured physical activity and sedentary time in a cohort of US adults followed for up to 13 years: The influence of removing early follow-up on associations with mortality. International Journal of Behavioral Nutrition and Physical Activity. 17. doi: 10.1186/s12966-020-00945-4. Full text in Research Archive Show summary

  Background: Observational studies linking physical activity with mortality are susceptible to reverse causation bias from undiagnosed and prevalent diseases. Researchers often attempt to deal with reverse causation bias by excluding deaths occurring within the first 1 or 2 years from the analysis, but it is unclear if excluding deaths within this time-frame is sufficient to remove bias. Methods: We examined associations between total and intensity-specific physical activity and sedentary time with all-cause mortality in a prospective cohort of 3542 individuals from the 2003–2006 NHANES cycles. In order to yield measures of association hypothesized as minimally influenced by reverse causation bias the primary analysis excluded individuals with < 5 years of follow-up. Accelerometer-measured physical activity was linked with recently updated vital status from the National Death Index with a median follow-up of 10.8 years. Results: Hazard ratios (95% confidence intervals) were 0.74 (0.53, 1.04), 0.52 (0.37, 0.73), and 0.61 (0.38, 1.01) for ascending quartiles of total physical activity against the least active reference. Hazard ratios for ascending moderate-to-vigorous physical activity quartiles against the reference were 0.67 (0.47, 1.96), 0.67 (0.47, 0.95), and 0.68 (0.39, 1.18). Associations for light intensity physical activity and sedentary time were smaller in magnitude and all confidence intervals included unity. Total activity and moderate-to-vigorous physical activity hazard ratios from analyses only excluding deaths within the first 2 years were inflated by 13 and 26% relative to analysis restricted to ≥5 years of follow-up. Conclusions: The pattern of associations suggested total physical activity and moderate-to-vigorous physical activity were associated with lower mortality after more than 10 years of follow-up and excluding the first 5 years of observation time to minimize the impact of reverse causation bias. Excluding deaths within the first 2 years appeared insufficient to minimize the impact of reserve causation bias.

• Haapala, Eero A.; Wiklund, Petri; Lintu, Niina; Tompuri, Tuomo; Väistö, Juuso & Finni, Taija [Show all 12 contributors for this article] (2020). Cardiorespiratory Fitness, Physical Activity, and Insulin Resistance in Children. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 52(5), p. 1144–1152. doi: 10.1249/MSS.0000000000002216. Full text in Research Archive Show summary

  Purpose: Few studies have investigated the independent and joint associations of cardiorespiratory fitness (CRF) and body fat percentage (BF%) with insulin resistance in children. We investigated the independent and combined associations of CRF and BF% with fasting glycemia and insulin resistance and their interactions with physical activity (PA) and sedentary time among 452 children age 6 to 8 yr. Methods: We assessed CRF with a maximal cycle ergometer exercise test and used allometrically scaled maximal power output (Wmax) for lean body mass (LM1.13) and body mass (BM1) as measures of CRF. The BF% and LM were measured by dual-energy X-ray absorptiometry, fasting glycemia by fasting plasma glucose, and insulin resistance by fasting serum insulin and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). The PA energy expenditure, moderate-to-vigorous PA (MVPA), and sedentary time were assessed by combined movement and heart rate sensor. Results: Wmax/LM1.13 was not associated with glucose (β = 0.065, 95% confidence interval [CI] = −0.031 to 0.161), insulin (β = −0.079, 95% CI = −0.172 to 0.015), or HOMA-IR (β = −0.065, 95% CI = −0.161 to 0.030). Wmax/BM1 was inversely associated with insulin (β = −0.289, 95% CI = −0.377 to −0.200) and HOMA-IR (β = −0.269, 95% CI = −0.359 to −0.180). The BF% was directly associated with insulin (β = 0.409, 95% CI = 0.325 to 0.494) and HOMA-IR (β = 0.390, 95% CI = 0.304 to 0.475). Higher Wmax/BM1, but not Wmax/LM1.13, was associated with lower insulin and HOMA-IR in children with higher BF%. Children with higher BF% and who had lower levels of MVPA or higher levels of sedentary time had the highest insulin and HOMA-IR. Conclusions: Children with higher BF% together with less MVPA or higher levels of sedentary time had the highest insulin and HOMA-IR. Cardiorespiratory fitness appropriately controlled for body size and composition using LM was not related to insulin resistance among children.

• Bull, Fiona C.; Al-Ansari, Salih S.; Biddle, Stuart; Borodulin, Katja; Buman, Matthew P. & Cardon, Greet [Show all 30 contributors for this article] (2020). World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine. ISSN 0306-3674. 54(24), p. 1451–1462. doi: 10.1136/bjsports-2020-102955. Full text in Research Archive Show summary

  Objectives: To describe new WHO 2020 guidelines on physical activity and sedentary behaviour. Methods: The guidelines were developed in accordance with WHO protocols. An expert Guideline Development Group reviewed evidence to assess associations between physical activity and sedentary behaviour for an agreed set of health outcomes and population groups. The assessment used and systematically updated recent relevant systematic reviews; new primary reviews addressed additional health outcomes or subpopulations. Results: The new guidelines address children, adolescents, adults, older adults and include new specific recommendations for pregnant and postpartum women and people living with chronic conditions or disability. All adults should undertake 150–300 min of moderate-intensity, or 75–150 min of vigorous-intensity physical activity, or some equivalent combination of moderate-intensity and vigorous-intensity aerobic physical activity, per week. Among children and adolescents, an average of 60 min/day of moderate-to-vigorous intensity aerobic physical activity across the week provides health benefits. The guidelines recommend regular muscle-strengthening activity for all age groups. Additionally, reducing sedentary behaviours is recommended across all age groups and abilities, although evidence was insufficient to quantify a sedentary behaviour threshold. Conclusion: These 2020 WHO guidelines update previous WHO recommendations released in 2010. They reaffirm messages that some physical activity is better than none, that more physical activity is better for optimal health outcomes and provide a new recommendation on reducing sedentary behaviours. These guidelines highlight the importance of regularly undertaking both aerobic and muscle strengthening activities and for the first time, there are specific recommendations for specific populations including for pregnant and postpartum women and people living with chronic conditions or disability. These guidelines should be used to inform national health policies aligned with the WHO Global Action Plan on Physical Activity 2018–2030 and to strengthen surveillance systems that track progress towards national and global targets.

• Júdice, Pedro B.; Hetherington-Rauth, Megan; Northstone, Kate; Andersen, Lars Bo; Wedderkopp, Niels & Ekelund, Ulf [Show all 7 contributors for this article] (2020). Changes in physical activity and sedentary patterns on cardiometabolic outcomes in the transition to adolescence: International Children's Accelerometry Database 2.0. Journal of Pediatrics. ISSN 0022-3476. 225, p. 166–173. doi: 10.1016/j.jpeds.2020.06.018. Full text in Research Archive Show summary

  Objective To examine the associations of changes in physical activity and sedentary patterns with changes in cardiometabolic outcomes from childhood to adolescence. Study design Youth from the International Children's Accelerometry Database (n = 1088; 55% girls), aged 8-13 years and followed for ∼4 years, were used in this analysis. Hip-mounted accelerometers were used and all physical activity intensities were expressed as the % of total wear-time. Sedentary time was separated into time spent in bouts <10 minutes and ≥10 minutes. A composite z score for cardiometabolic risk (CMR score) was computed by summing the standardized values for systolic and diastolic blood pressure, triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), and the inverse high-density lipoprotein cholesterol. Multivariate analyses were performed using adjusted linear regression models. Results Increase in sedentary time was unfavorably associated with changes in CMR score (β = 0.021; CI 0.004-0.037), TG (β = 0.003; CI 0.001-0.005), and diastolic blood pressure (β = 0.068; CI 0.009-0.128). Decrease in moderate-to-vigorous physical activity was unfavorably associated with changes in LDL-c (β = −0.009; CI −0.017 to −0.001) and TG (β = −0.007; CI −0.013 to −0.001). Increase in ≥10 minutes sedentary time was unfavorably associated with changes in CMR score (β = 0.017; CI 0.004-0.030), LDL-c (β = 0.003; CI 0.000-0.005), and TG (β = 0.003; CI 0.000-0.004). Decrease in light-intensity physical activity was unfavorably associated with changes in CMR score (β = −0.020; CI = −0.040 to 0.000). Conclusions More physical activity and less prolonged sedentary time are beneficial for cardiometabolic health in youth transitioning to adolescence.

• Johnston, William; Júdice, Pedro B.; Molina-Garcia, Pablo; Mühlen, Jan M; Skovgaard, Esben Lykke & Stang, Julie [Show all 15 contributors for this article] (2020). Recommendations for determining the validity of consumer wearable and smartphone step count: Expert statement and checklist of the INTERLIVE network. British Journal of Sports Medicine. ISSN 0306-3674. doi: 10.1136/bjsports-2020-103147. Full text in Research Archive Show summary

  Consumer wearable and smartphone devices provide an accessible means to objectively measure physical activity (PA) through step counts. With the increasing proliferation of this technology, consumers, practitioners and researchers are interested in leveraging these devices as a means to track and facilitate PA behavioural change. However, while the acceptance of these devices is increasing, the validity of many consumer devices have not been rigorously and transparently evaluated. The Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives to develop best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice consumer wearable and smartphone step counter validation protocol. A two-step process was used to aggregate data and form a scientific foundation for the development of an optimal and feasible validation protocol: (1) a systematic literature review and (2) additional searches of the wider literature pertaining to factors that may introduce bias during the validation of these devices. The systematic literature review process identified 2897 potential articles, with 85 articles deemed eligible for the final dataset. From the synthesised data, we identified a set of six key domains to be considered during design and reporting of validation studies: target population, criterion measure, index measure, validation conditions, data processing and statistical analysis. Based on these six domains, a set of key variables of interest were identified and a ‘basic’ and ‘advanced’ multistage protocol for the validation of consumer wearable and smartphone step counters was developed. The INTERLIVE consortium recommends that the proposed protocol is used when considering the validation of any consumer wearable or smartphone step counter. Checklists have been provided to guide validation protocol development and reporting. The network also provide guidance for future research activities, highlighting the imminent need for the development of feasible alternative ‘gold-standard’ criterion measures for free-living validation. Adherence to these validation and reporting standards will help ensure methodological and reporting consistency, facilitating comparison between consumer devices. Ultimately, this will ensure that as these devices are integrated into standard medical care, consumers, practitioners, industry and researchers can use this technology safely and to its full potential.

• Rodriguez-Martinez, Andrea; Zhou, Bin; Sophiea, Marisa K.; Bentham, James; Paciorek, Christopher J. & Turilli, Maria L.C. [Show all 54 contributors for this article] (2020). Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants. The Lancet. ISSN 0140-6736. 396(10261), p. 1511–1524. doi: 10.1016/S0140-6736(20)31859-6. Full text in Research Archive Show summary

  Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m². In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in subSaharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks. Funding Wellcome Trust, AstraZeneca Young Health Programme, EU.

• Zou, Liye; Xiao, Tao; Cao, Chao; Smith, Lee; Imm, Kellie & Grabovac, Igor [Show all 14 contributors for this article] (2020). Tai Chi for chronic illness management: Synthesizing current evidence from meta-analyses of randomized controlled trials. American Journal of Medicine. ISSN 0002-9343. 132(2), p. 194–205. doi: 10.1016/j.amjmed.2020.08.015. Full text in Research Archive Show summary

  An umbrella review of systematic reviews and meta-analyses of randomized controlled trials (RCTs) was conducted to evaluate the existing evidence of Tai Chi as a mind-body exercise for chronic illness management. MEDLINE/PubMed and Embase databases were searched from inception until March 31, 2019, for meta-analyses of at least two RCTs that investigated health outcomes associated with Tai Chi intervention. Evidence of significant outcomes (P value < 0.05) was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. This review identified 45 meta-analyses of RCTs and calculated 142 summary estimates among adults living with 16 types of chronic illnesses. Statistically significant results (P value < 0.05) were identified for 81 of the 142 outcomes (57.0%), of which 45 estimates presenting 30 unique outcomes across 14 chronic illnesses were supported by high (n = 1) or moderate (n = 44) evidence. Moderate evidence suggests that Tai Chi intervention improved physical functions and disease-specific outcomes compared with nonactive controls and improved cardiorespiratory fitness compared with active controls among adults with diverse chronic illnesses. Between-study heterogeneity and publication bias were observed in some meta-analyses.

• Júdice, Pedro B.; Magalhães, João P.; Rosa, Gil B.; Correia, Inês R.; Ekelund, Ulf & Sardinha, Luís B. (2020). Sedentary behavior compensation to 1-year exercise RCT in patients with type 2 diabetes. Translational Sports Medicine (TSM). 3(2), p. 154–163. doi: 10.1002/tsm2.96. Full text in Research Archive
• Beldo, Sigurd; Morseth, Bente; Christoffersen, Tore; Halvorsen, Peder Andreas; Hansen, Bjørge Hermann & Furberg, Anne-Sofie [Show all 8 contributors for this article] (2020). Prevalence of accelerometer-measured physical activity in adolescents in Fit Futures - part of the Tromsø Study. BMC Public Health. 20. doi: 10.1186/s12889-020-09171-w. Full text in Research Archive Show summary

  <i>Background</i> - Previous studies show large variations in physical activity (PA) levels among adolescents. However, the number of studies is limited and even fewer studies have assessed PA in adolescents by accelerometer devices. This study aimed to describe accelerometer-measured PA levels in adolescents in a population-based cohort in Northern Norway.<p> <p><i>Methods</i> - In 611 students aged 16–17 years attending the Fit Futures Study, PA was measured by Actigraph GT3X for seven consecutive days. PA was expressed as total PA volume (counts per minute, CPM), time spent in intensity zones, steps per day, and fulfilment of WHO recommendation (i.e. accumulation of 60 min or more of at least moderate intensity PA per day). Potential correlates of PA such as sex, socioeconomic status, study program, self-perceived health, and PA variations by weekday versus weekend were also examined.<p> <p><i>Results</i> - 16% of the girls and 25% of the boys fulfilled current WHO-recommendations. Total PA volume (CPM) was higher in boys than in girls (353 (SD 130) versus 326 (SD 114) CPM, <i>p</i> < 0.05). PA levels differed with study program and increased with better self-perceived health, but were not associated with socioeconomic status. Both boys and girls were more active on weekdays than weekends (altogether; 350 (SD 124) versus 299 (SD 178) CPM, <i>p</i> < 0.05).<p> <p><i>Conclusions</i> - In this cohort of adolescents, less than 25% of 16–17-year-old boys and girls fulfilled the WHO recommendations. The levels of physical activity in 16–17-year-old adolescents are similar to previous data reported in adults.

• Ekelund, Ulf; Tarp, Jakob; Fagerland, Morten Wang; Steene-Johannessen, Jostein; Hansen, Bjørge Hermann & Jefferis, Barbara [Show all 23 contributors for this article] (2020). Joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality: a harmonised meta-analysis in more than 44 000 middle-aged and older individuals. British Journal of Sports Medicine. ISSN 0306-3674. 54(24), p. 1499–1506. doi: 10.1136/bjsports-2020-103270. Full text in Research Archive Show summary

  Objectives: To examine the joint associations of accelerometer-measured physical activity and sedentary time with all-cause mortality. Methods: We conducted a harmonised meta-analysis including nine prospective cohort studies from four countries. 44 370 men and women were followed for 4.0 to 14.5 years during which 3451 participants died (7.8% mortality rate). Associations between different combinations of moderate-to-vigorous intensity physical activity (MVPA) and sedentary time were analysed at study level using Cox proportional hazards regression analysis and summarised using random effects meta-analysis. Results: Across cohorts, the average time spent sedentary ranged from 8.5 hours/day to 10.5 hours/day and 8 min/day to 35 min/day for MVPA. Compared with the referent group (highest physical activity/lowest sedentary time), the risk of death increased with lower levels of MVPA and greater amounts of sedentary time. Among those in the highest third of MVPA, the risk of death was not statistically different from the referent for those in the middle (16%; 95% CI 0.87% to 1.54%) and highest (40%; 95% CI 0.87% to 2.26%) thirds of sedentary time. Those in the lowest third of MVPA had a greater risk of death in all combinations with sedentary time; 65% (95% CI 1.25% to 2.19%), 65% (95% CI 1.24% to 2.21%) and 263% (95% CI 1.93% to 3.57%), respectively. Conclusion: Higher sedentary time is associated with higher mortality in less active individuals when measured by accelerometry. About 30–40 min of MVPA per day attenuate the association between sedentary time and risk of death, which is lower than previous estimates from self-reported data.

• Dempsey, Paddy; Biddle, Stuart JH; Buman, Matthew P.; Chastin, Sebastian; Ekelund, Ulf & Friedenreich, Christine M. [Show all 12 contributors for this article] (2020). New global guidelines on sedentary behaviour and health for adults: broadening the behavioural targets. International Journal of Behavioral Nutrition and Physical Activity. 17. doi: 10.1186/s12966-020-01044-0. Full text in Research Archive Show summary

  Background: In 2018, the World Health Organisation (WHO) commenced a program of work to update the 2010 Global Recommendations on Physical Activity for Health, for the first-time providing population-based guidelines on sedentary behaviour. This paper briefly summarizes and highlights the scientific evidence behind the new sedentary behaviour guidelines for all adults and discusses its strengths and limitations, including evidence gaps/research needs and potential implications for public health practice. Methods: An overview of the scope and methods used to update the evidence is provided, along with quality assessment and grading methods for the eligible new systematic reviews. The literature search update was conducted for WHO by an external team and reviewers used the AMSTAR 2 (Assessment of Multiple Systematic Reviews) tool for critical appraisal of the systematic reviews under consideration for inclusion. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) method was used to rate the certainty (i.e. very low to high) of the evidence. Results: The updated systematic review identified 22 new reviews published from 2017 up to August 2019, 14 of which were incorporated into the final evidence profiles. Overall, there was moderate certainty evidence that higher amounts of sedentary behaviour increase the risk for all-cause, cardiovascular disease (CVD) and cancer mortality, as well as incidence of CVD, cancer, and type 2 diabetes. However, evidence was deemed insufficient at present to set quantified (time-based) recommendations for sedentary time. Moderate certainty evidence also showed that associations between sedentary behaviour and all-cause, CVD and cancer mortality vary by level of moderate-to-vigorous physical activity (MVPA), which underpinned additional guidance around MVPA in the context of high sedentary time. Finally, there was insufficient or low-certainty systematic review evidence on the type or domain of sedentary behaviour, or the frequency and/or duration of bouts or breaks in sedentary behaviour, to make specific recommendations for the health outcomes examined. Conclusions: The WHO 2020 guidelines are based on the latest evidence on sedentary behaviour and health, along with interactions between sedentary behaviour and MVPA, and support implementing public health programmes and policies aimed at increasing MVPA and limiting sedentary behaviour. Important evidence gaps and research opportunities are identified.

• Chaput, Jean-Philippe; Willumsen, Juana F.; Bull, Fiona; Chou, Roger; Ekelund, Ulf & Firth, Joseph [Show all 9 contributors for this article] (2020). 2020 WHO guidelines on physical activity and sedentary behaviour for children and adolescents aged 5–17 years: summary of the evidence. International Journal of Behavioral Nutrition and Physical Activity. 17. doi: 10.1186/s12966-020-01037-z. Full text in Research Archive Show summary

  Background: The World Health Organization (WHO) released in 2020 updated global guidelines on physical activity and sedentary behaviour for children, adolescents, adults, older adults and sub-populations such as pregnant and postpartum women and those living with chronic conditions or disabilities. Objective: To summarize the evidence on the associations between physical activity, sedentary behaviour, and health-related outcomes used to inform the 2020 WHO guidelines on physical activity and sedentary behaviour for children and adolescents aged 5–17 years. Methods: The update of the WHO guideline recommendations for children and adolescents utilized and systematically updated the evidence syntheses on physical activity and sedentary behaviour conducted for the 2016 Canadian 24-Hour Movement Guidelines for Children and Youth, the 2019 Australian 24-Hour Movement Guidelines for Children and Young People (5–17 years), and the 2018 Physical Activity Guidelines for Americans, Second Edition. Systematic reviews published from 2017 up to July 2019 that addressed the key questions were identified, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rate the certainty of the evidence for the entire body of evidence. Results: The updated literature search yielded 21 relevant systematic reviews. The evidence base reviewed (i.e., existing and new systematic reviews) provided evidence that greater amounts and higher intensities of physical activity as well as different types of physical activity (i.e., aerobic and muscle and bone strengthening activities) are associated with improved health outcomes (primarily intermediate outcomes). There was sufficient evidence to support recommendations on limiting sedentary behaviours, which was not addressed in the 2010 WHO guidelines. However, there is still insufficient evidence available to fully describe the dose-response relationships between physical activity or sedentary behaviour and health outcomes, and whether the associations vary by type or domain of physical activity or sedentary behaviour. Conclusions: Addressing the identified research gaps will better inform guideline recommendations in children and adolescents, and future work should aim to prioritize these areas of research. In the meantime, investment and leadership is needed to scale up known effective policies and programs aimed at increasing activity in children and adolescents.

• Ding, Ding; Mielke, Gregore I.; Silva, Inácio Crochemore M.; Wehrmeister, Fernando César; Horta, Bernardo L. & Brage, Soren [Show all 8 contributors for this article] (2020). Prenatal and birth predictors of objectively measured physical activity and sedentary time in three population-based birth cohorts in Brazil. Scientific Reports. 10(2020). doi: 10.1038/s41598-019-57070-x. Full text in Research Archive Show summary

  Physical inactivity is a global pandemic with no signs of improvement. Prolonged sitting time is an emerging risk factor that exacerbates the health consequences of physical inactivity. Both behaviours are influenced by various individual and environmental factors but it remains unknown whether early-life exposures “program” these behaviours in later life. The current evidence is limited by a small number of studies which were primarily conducted in high-income countries, and a narrow range of early-life variables examined. Using data from three population-based Brazilian birth cohorts (analytical samples: n = 2740 for 1982 cohort, aged 30 years; n = 3592 for 1993 cohort, aged 18; n = 2603 for 2004 cohort, aged 6), we show that being female and higher family socioeconomic status at birth are strong and consistent predictors of lower physical activity and higher sedentary time from childhood to adulthood. Meanwhile, higher birth weight and lower birth order may also predict lower physical activity and higher sedentary time. Our findings are distinct from evidence from high-income countries, suggesting the importance of broader socioeconomic context in determining individual’s activity patterns through the life- course. Such evidence is essential for understanding the biological etiology and socioeconomic context of physical activity and sedentary behaviour at an early stage in life.

• Sanchez-Lastra, Miguel A.; Ding, Ding; Dalene, Knut Eirik; Ekelund, Ulf & Tarp, Jakob (2020). Physical activity and mortality across levels of adiposity: A prospective cohort study from the UK biobank. Mayo Clinic proceedings. ISSN 0025-6196. 96(1), p. 105–119. doi: 10.1016/j.mayocp.2020.06.049. Full text in Research Archive Show summary

  Objective: To examine the combined and stratified associations of physical activity and adiposity measures, modelled as body mass index (BMI), abdominal adiposity (waist circumference), and body fat percentage (BF) with all-cause mortality. Patients and Methods: Using the UK Biobank cohort, we extracted quintiles of self-reported weekly physical activity. Categories of measured BMI, waist circumference, and BF were generated. Joint associations between physical activity-adiposity categories and mortality were examined using Cox proportional hazards models adjusted for demographic, behavioral, and clinical covariates. Physical activity-mortality associations were also examined within adiposity strata. Participants were followed from baseline (2006 to 2010) through January 31, 2018. Results: A total of 295,917 participants (median follow-up, 8.9 years, during which 6684 deaths occurred) were included. High physical activity was associated with lower risk of premature mortality in all strata of adiposity except for those with BMI ≥35 kg/m2. Highest risk (HR, 1.54; 95% CI; 1.33 to 1.79) was observed in individuals with low physical activity and high BF as compared with the high physical activity–low BF referent. High physical activity attenuated the risk of high adiposity when using BF (HR, 1.24; 95% CI; 1.04 to 1.49), but the association was weaker with BMI (HR, 1.45; 95% CI; 1.21 to 1.73). Physical activity also attenuated the association between mortality and high waist circumference. Conclusion: Low physical activity and adiposity were both associated with a higher risk of premature mortality, but high physical activity attenuated the increased risk with adiposity irrespective of adiposity metric, except in those with a BMI ≥35 kg/m2.

• Bernhardsen, Guro Pauck; Stensrud, Trine; Nystad, Wenche & Ekelund, Ulf (2020). Pre- and post-natal factors and physical activity in childhood: The Norwegian Mother, Father and Child Cohort study. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(11), p. 2264–2274. doi: 10.1111/sms.13781. Full text in Research Archive Show summary

  Few studies have examined the possibility that pre‐ and post‐natal factors may be non‐linearly associated with later physical activity. We used data from the Norwegian Mother, Father and Child Cohort study (MoBa) and the Medical Birth Registry of Norway (MBRN), including 48 672 children with available data on leisure time physical activity (LTPA) at child's age 7 years. Restricted cubic and linear splines or linear regression was used to examine the associations between maternal pre‐pregnancy BMI, birth weight for gestational age, and infant weight gain from birth to 1 year with LTPA (frequency/wk) in 7‐year‐old children. The results suggest no associations between maternal pre‐pregnancy BMI, birth weight, and infant weight gain on subsequent LTPA in girls. Maternal pre‐pregnancy BMI and birth weight may be non‐linearly associated with LTPA in 7‐year‐old boys. Infant weight gain (change in weight z‐score from birth to 1 year) may be weakly linearly associated with LTPA in boys. Pre‐ and post‐natal factors may therefore influence LTPA in childhood differently in boys and girls. Maternal pre‐pregnancy BMI and birth weight are positively associated with LTPA at the lower ends of the maternal pre‐pregnancy BMI and birth weight continuums in boys. The negative associations at the higher ends of the continuums and the positive association between infant weight gain and LTPA in boys may not be important and needs further replication.

• Bernhardsen, Guro Pauck; Stensrud, Trine; Hansen, Bjørge Hermann; Steene-Johannessen, Jostein; Kolle, Elin & Nystad, Wenche [Show all 17 contributors for this article] (2020). Birth weight, cardiometabolic risk factors and effect modification of physical activity in children and adolescents: pooled data from 12 international studies. International Journal of Obesity. ISSN 0307-0565. 44(10), p. 2052–2063. doi: 10.1038/s41366-020-0612-9. Full text in Research Archive Show summary

  Objectives: Low and high birth weight is associated with higher levels of cardiometabolic risk factors and adiposity in children and adolescents, and increases the risk of cardiovascular diseases, obesity, and early mortality later in life. Moderate-to-vigorous physical activity (MVPA) is associated with lower cardiometabolic risk factors and may mitigate the detrimental consequences of high or low birth weight. Thus, we examined whether MVPA modified the associations between birth weight and cardiometabolic risk factors in children and adolescents. Methods: We used pooled individual data from 12 cohort- or cross-sectional studies including 9,100 children and adolescents. Birth weight was measured at birth or maternally reported retrospectively. Device-measured physical activity (PA) and cardiometabolic risk factors were measured in childhood or adolescence. We tested for associations between birth weight, MVPA, and cardiometabolic risk factors using multilevel linear regression, including study as a random factor. We tested for interaction between birth weight and MVPA by introducing the interaction term in the models (birth weight x MVPA). Results: Most of the associations between birth weight (kg) and cardiometabolic risk factors were not modified by MVPA (min/day), except between birth weight and waist circumference (cm) in children (p = 0.005) and HDL-cholesterol (mmol/l) in adolescents (p = 0.040). Sensitivity analyses suggested that some of the associations were modified by VPA, i.e., the associations between birth weight and diastolic blood pressure (mmHg) in children (p = 0.009) and LDL- cholesterol (mmol/l) (p = 0.009) and triglycerides (mmol/l) in adolescents (p = 0.028). Conclusion: MVPA appears not to consistently modify the associations between low birth weight and cardiometabolic risk. In contrast, MVPA may mitigate the association between higher birth weight and higher waist circumference in children. MVPA is consistently associated with a lower cardiometabolic risk across the birth weight spectrum. Optimal prenatal growth and subsequent PA are both important in relation to cardiometabolic health in children and adolescents.

• Hansen, Bjørge Hermann; Dalene, Knut Eirik; Ekelund, Ulf; Fagerland, Morten; Kolle, Elin & Steene-Johannessen, Jostein [Show all 8 contributors for this article] (2020). Step by step: Association of device‐measured daily steps with all‐cause mortality - A prospective cohort Study. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(9), p. 1705–1711. doi: 10.1111/sms.13726. Full text in Research Archive Show summary

  Introduction: Walking is free, does not require special training, and can be done almost everywhere. Therefore, walking is a feasible behavior on which to tailor public health messages. This study assesses the prospective association and dose‐response relationship between daily steps and all‐cause mortality. Materials and Methods: Daily steps were measured by waist‐mounted accelerometers in 2183 individuals (53% women) for seven consecutive days at baseline (2008‐09). Participants were followed for a median period of 9.1 years and associations between steps and all‐cause mortality determined by registry linkage were assessed using Cox proportional hazard regression with adjustment for relevant covariates. Results: Mean age was 57.0 (SD 10.9) years at baseline. Median (IQR) daily steps across ascending quartiles were 4651 (3495‐5325), 6862 (6388‐7350), 8670 (8215‐9186), and 11 467 (10 556‐13 110), respectively. During follow‐up, 119 individuals died (68% men). Higher number of daily steps was associated with a lower risk of all‐cause mortality with hazard ratios of 1.00 (referent), 0.52 (0.29‐0.93), 0.50 (0.27‐0.94), and 0.43 (0.21‐0.88) across ascending quartiles of daily steps in the multivariable‐adjusted model with follow‐up commencing 2 years after baseline. Risk differences per 1000 individuals for ascending quartiles were 6.8 (2.9‐9.3), 7.1 (0.8‐11.1), and 8.0 (1.7‐12.1), respectively. Conclusions: Daily steps were associated with lower mortality risk in a non‐linear dose‐response pattern. The risk is almost halved when comparing the least active referent against the second quartile equivalent to a difference of about 2200 daily steps. Encouraging those least active to increase their daily steps may have substantial public health implications.

• Taddei, Cristina; Zhou, Bin; Bixby, Honor; Carrillo-Larco, Rodrigo M.; Danaei, Goodarz & Jackson, Rod T. [Show all 55 contributors for this article] (2020). Repositioning of the global epicentre of non-optimal cholesterol. Nature. ISSN 0028-0836. 582(7810), p. 73–77. doi: 10.1038/s41586-020-2338-1. Full text in Research Archive Show summary

  High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.

• Kolle, Elin; Solberg, Runar Barstad; Säfvenbom, Reidar; Dyrstad, Sindre Mikal; Berntsen, Sveinung & Resaland, Geir Kåre [Show all 10 contributors for this article] (2020). The effect of a school-based intervention on physical activity, cardiorespiratory fitness and muscle strength: the School in Motion cluster randomized trial. International Journal of Behavioral Nutrition and Physical Activity. 17(1). doi: 10.1186/s12966-020-01060-0. Full text in Research Archive Show summary

  Background: Physical activity (PA) declines throughout adolescence, therefore PA promotion during this period is important. We analyzed the effect of two school-based PA interventions on daily PA levels, cardiorespiratory fitness (CRF) and muscle strength among adolescents. Methods: For the nine-month School in Motion intervention study (ScIM), we cluster-randomized 30 Norwegian secondary schools (N = 2084, mean age [SD] = 14 [0.3] years) to one of three study arms. The physically active learning (PAL) intervention included 30 min physically active learning, 30 min PA and a 60 min physical education (PE) lesson per week. The Don’t worry-Be happy (DWBH) intervention included a 60 min PA lesson and a 60 min PE lesson per week, both tailored to promote friendships and wellbeing. Both intervention arms were designed to engage the adolescents in 120 min of PA per week in addition to recess and mandatory PE lessons. The control group continued as per usual, including the standard amount of mandatory PE. PA (main outcome) was assessed by accelerometers, CRF and muscle strength (secondary outcomes) were assessed by an intermittent running test and selected tests from the Eurofit test battery. Results: Daily PA and time spent in moderate- to vigorous-intensity PA (MVPA) decreased in all groups throughout the intervention. The mean difference in PA level and MVPA for participants in the PAL-intervention arm was 34.7 cpm (95% CI: 4.1, 65.3) and 4.7 min/day (95% CI: 0.6, 8.8) higher, respectively, compared to the control arm. There were no significant intervention effects on daily PA level, MVPA or time spent sedentary for adolescents in the DWBH-intervention arm. Adolescents in the PAL-intervention arm increased distance covered in the running test compared to controls (19.8 m, 95% CI: 10.4, 29.1), whilst a negative intervention effect was observed among adolescents in the DWBH-intervention arm (− 11.6 m, 95% CI: − 22.0, − 1.1). Conclusion: The PAL-intervention resulted in a significantly smaller decrease in daily PA level, time spent in MVPA, and increased CRF compared to controls. Our results indicate that a teacher-led intervention, including three unique intervention components, is effective in curbing the decline in PA observed across our cohort and improving CRF.

• Sagelv, Edvard Hamnvik; Ekelund, Ulf; Hopstock, Laila Arnesdatter; Aars, Nils Abel; Fimland, Marius Steiro & Jacobsen, Bjarne K. [Show all 9 contributors for this article] (2020). Do declines in occupational physical activity contribute to population gains in body mass index? Tromsø Study 1974–2016. Occupational and Environmental Medicine. ISSN 1351-0711. 78(0), p. 203–210. doi: 10.1136/oemed-2020-106874. Full text in Research Archive Show summary

  Objective: To examine whether occupational physical activity changes predict future body mass index (BMI) changes. Methods: This longitudinal cohort study included adult participants attending ≥3 consecutive Tromsø Study surveys (examinations 1, 2 and 3) from 1974 to 2016 (N=11 308). If a participant attended >3 surveys, the three most recent surveys were included. Occupational physical activity change (assessed by the Saltin-Grimby Physical Activity Level Scale) was computed from the first to the second examination, categorised into persistently inactive (n=3692), persistently active (n=5560), active to inactive (n=741) and inactive to active (n=1315). BMI change was calculated from the second to the third examination (height being fixed at the second examination) and regressed on preceding occupational physical activity changes using analysis of covariance adjusted for sex, birth year, smoking, education and BMI at examination 2. Results: Overall, BMI increased by 0.84 kg/m2 (95% CI 0.82 to 0.89). Following adjustments as described previously, we observed no differences in BMI increase between the occupational physical activity change groups (Persistently Inactive: 0.81 kg/m2, 95% CI 0.75 to 0.87; Persistently Active: 0.87 kg/m2, 95% CI 0.82 to 0.92; Active to Inactive: 0.81 kg/m2, 95% CI 0.67 to 0.94; Inactive to Active: 0.91 kg/m2, 95% CI 0.81 to 1.01; p=0.25). Conclusion: We observed no prospective association between occupational physical activity changes and subsequent BMI changes. Our findings do not support the hypothesis that occupational physical activity declines contributed to population BMI gains over the past decades. Public health initiatives aimed at weight gain prevention may have greater success if focusing on other aspects than occupational physical activity.

• Sagelv, Edvard Hamnvik; Hopstock, Laila Arnesdatter; Johansson, Jonas; Hansen, Bjørge Hermann; Søren, Brage & Horsch, Alexander [Show all 8 contributors for this article] (2020). Criterion validity of two physical activity and one sedentary time questionnaire against accelerometry in a large cohort of adults and older adults. BMJ Open sport & exercise medicine. 6(1). doi: 10.1136/bmjsem-2019-000661. Full text in Research Archive Show summary

  Objectives: We compared the ability of physical activity and sitting time questionnaires (PAQ) for ranking individuals versus continuous volume calculations (physical activity level (PAL), metabolic equivalents of task (MET), sitting hours) against accelerometry measured physical activity as our criterion. Methods: Participants in a cohort from the Tromsø Study completed three questionnaires; (1) The Saltin-Grimby Physical Activity Level Scale (SGPALS) (n=4040); (2) The Physical Activity Frequency, Intensity and Duration (PAFID) questionnaire (n=5902)) calculated as MET-hours·week-1 and (3) The International Physical Activity questionnaire (IPAQ) short-form sitting question (n=4896). We validated the questionnaires against the following accelerometry (Actigraph wGT3X-BT) estimates: vector magnitude counts per minute, steps∙day-1, time (minutes·day-1) in sedentary behaviour, light physical activity, moderate and vigorous physical activity (MVPA) non-bouted and ≥10 min bouted MVPA. Results: Ranking of physical activity according to the SGPALS and quartiles (Q) of MET-hours∙week-1 from the PAFID were both positively associated with accelerometry estimates of physical activity (p<0.001) but correlations with accelerometry estimates were weak (SGPALS (PAL): r=0.11 to 0.26, p<0.001) and weak-to-moderate (PAFID: r=0.39 to 0.44, p<0.01). There was 1 hour of accelerometry measured sedentary time from Q1 to Q4 in the IPAQ sitting question (p<0.001) and also weak correlations (r=0.22, p<0.01). Conclusion: Ranking of physical activity levels measured with PAQs appears to have higher validity than energy expenditure calculations. Self-reported sedentary time poorly reflects accelerometry measured sedentary time. These two PAQs can be used for ranking individuals into different physical activity categories supporting previous studies using these instruments when assessing associations with health outcomes.

• Santos, Diana A; Magalhães, João P.; Júdice, Pedro B.; Correia, Ines R; Minderico, Cláudia S. & Ekelund, Ulf [Show all 7 contributors for this article] (2019). Fitness Mediates Activity and Sedentary Patterns Associations with Adiposity in Youth. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 51(2), p. 323–329. doi: 10.1249/MSS.0000000000001785. Full text in Research Archive Show summary

  Purpose: We aimed to examine the cross-sectional associations of patterns of sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) with total fat mass index (FMI) and abdominal FMI (FMIabd) in children, and additionally, to analyze if cardiorespiratory fitness (CRF) mediated these associations. Methods: Fat mass index and FMIabd were assessed with dual-energy X-ray absorptiometry in 333 participants (172 girls) age 9 to 11 yr. MVPA, ST, breaks in ST per sedentary hour (BST/ST) and the number of daily sedentary bouts with various lengths (1–4, 5–9, 10–14, and Q15 min) were assessed with accelerometry and CRF using a maximal cycle test. Hayes_ PROCESS macro for SPSS was used for mediation analysis. Results: The number of shorter sedentary bouts (1–4 min) was inversely associated with FMI (A = j0.108), whereas longer sedentary bouts (5–9 min, A = 0.169; 10–14 min, A = 0.193; Q15 min, A = 0.377) had a positive association, independent of MVPA (P G 0.05). A similar trend was found for FMIabd. Moderateto-vigorous physical activity was negatively related to FMI (A = j0.029) and to FMIabd (A = j0.003). There were no main associations for ST and BST/ST (P 9 0.05). Cardiorespiratory fitness was inversely related to total and abdominal adiposity, and a large portion (40.9– 65.7%) of the associations of MVPA and sedentary bouts with both FMI and FMIabd were mediated by CRF. Conclusions: Time in MVPA and accumulating ST in shorter sedentary bouts is inversely related to adiposity. However, these associations may be mediated by CRF. Emphasis should be given to programs that target increases in MVPA, which may influence CRF while reducing sedentary recreational behaviors.

• Sagelv, Edvard Hamnvik; Ekelund, Ulf; Pedersen, Sigurd; Brage, Søren; Hansen, Bjørge Hermann & Johansson, Jonas [Show all 11 contributors for this article] (2019). Physical activity levels in adults and elderly from triaxial and uniaxial accelerometry. The Tromsø Study. PLOS ONE. 14:e0225670(12), p. 1–17. doi: 10.1371/journal.pone.0225670. Full text in Research Archive Show summary

  <i>Introduction</i> - Surveillance of physical activity at the population level increases the knowledge on levels and trends of physical activity, which may support public health initiatives to promote physical activity. Physical activity assessed by accelerometry is challenged by varying data processing procedures, which influences the outcome. We aimed to describe the levels and prevalence estimates of physical activity, and to examine how triaxial and uniaxial accelerometry data influences these estimates, in a large population-based cohort of Norwegian adults.<p> <p><i>Methods</i> - This cross-sectional study included 5918 women and men aged 40–84 years who participated in the seventh wave of the Tromsø Study (2015–16). The participants wore an ActiGraph wGT3X-BT accelerometer attached to the hip for 24 hours per day over seven consecutive days. Accelerometry variables were expressed as volume (counts·minute-1 and steps·day-1) and as minutes per day in sedentary, light physical activity and moderate and vigorous physical activity (MVPA).<p> <p><i>Results</i> - From triaxial accelerometry data, 22% (95% confidence interval (CI): 21–23%) of the participants fulfilled the current global recommendations for physical activity (≥150 minutes of MVPA per week in ≥10-minute bouts), while 70% (95% CI: 69–71%) accumulated ≥150 minutes of non-bouted MVPA per week. When analysing uniaxial data, 18% fulfilled the current recommendations (i.e. 20% difference compared with triaxial data), and 55% (95% CI: 53–56%) accumulated ≥150 minutes of non-bouted MVPA per week. We observed approximately 100 less minutes of sedentary time and 90 minutes more of light physical activity from triaxial data compared with uniaxial data (p<0.001).<p> <p><i>Conclusion</i> - The prevalence estimates of sufficiently active adults and elderly are more than three times higher (22% vs. 70%) when comparing triaxial bouted and non-bouted MVPA. Physical activity estimates are highly dependent on accelerometry data processing criteria and on different definitions of physical activity recommendations, which may influence prevalence estimates and tracking of physical activity patterns over time.

• Bixby, Honor; Bentham, James; Zhou, Bin; Cesare, Mariachiara Di; Paciorek, Christopher J. & Bennett, James E. [Show all 51 contributors for this article] (2019). Rising rural body-mass index is the main driver of the global obesity epidemic in adults. Nature. ISSN 0028-0836. 569, p. 260–264. doi: 10.1038/s41586-019-1171-x. Full text in Research Archive Show summary

  Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities1,2. This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity3,4,5,6. Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017—and more than 80% in some low- and middle-income regions—was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing—and in some countries reversal—of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.

• Silva, Bruna Gonçalves Cordeiro da; Silva, Inácio Crochemore Mohnsam da; Ekelund, Ulf; Brage, Søren; Ong, Ken K. & Rolfe, Emanuella de Lucia [Show all 10 contributors for this article] (2019). Associations of physical activity and sedentary time with body composition in Brazilian young adults. Scientific Reports. 9(1). doi: 10.1038/s41598-019-41935-2. Full text in Research Archive Show summary

  The findings of studies on the association between physical activity and adiposity are not consistent, and most are cross-sectional and used only self-reported measures. The aims of this study were to evaluate: 1) independent and combined cross-sectional associations of objectively-measured physical activity and sedentary time with body composition outcomes at 30 years, and 2) prospective associations of changes in self-reported physical activity from 23 to 30 years with the same outcomes in participants from the 1982 Pelotas (Brazil) Birth Cohort. Body mass index, waist circumference, visceral abdominal fat, fat mass index, and android/gynoid fat ratio were the outcomes. 3,206 participants were analysed. In cross-sectional analyses, higher objectively-measured moderate-to-vigorous physical activity was associated with lower body mass index (β = 0.017, 95%CI: −0.026; −0.009), waist circumference (β = −0.043, 95%CI: −0.061; −0.025), visceral abdominal fat (β = −0.006, 95%CI: −0.009; −0.003), and fat mass index (β = −0.015, 95%CI: −0.021; −0.009), independent of sedentary time. Sedentary time was independently associated only with higher fat mass index (β = 0.003, 95%CI: 0.001; 0.005). In longitudinal analyses, using self-reported measure, adiposity was lower among those who were consistently active or who became active. Adiposity was similar among the “became inactive” and “consistently inactive” subjects. Our findings suggest metabolic benefits from engagement in physical activity throughout young adulthood, with stronger associations on concurrent levels.

• Ekelund, Ulf & Lee, I-Min (2019). Will new physical activity guidelines prevent weight gain? Nature Reviews Endocrinology. ISSN 1759-5029. 15(3), p. 131–132. doi: 10.1038/s41574-018-0153-7. Full text in Research Archive
• Renninger, Marius; Hansen, Bjørge Hermann; Steene-Johannessen, Jostein; Kriemler, Susi; Froberg, Karsten & Northstone, Kate [Show all 10 contributors for this article] (2019). Associations between accelerometry measured physical activity and sedentary time and the metabolic syndrome: A meta-analysis of more than 6000 children and adolescents. Pediatric Obesity. ISSN 2047-6302. 15, p. 1–9. doi: 10.1111/ijpo.12578. Full text in Research Archive Show summary

  Background: Metabolic syndrome is increasingly prevalent in the pediatric population. To prevent an early onset, knowledge about its association with modifiable lifestyle factors is needed. Objectives: To estimate the prevalence of the metabolic syndrome and examine its cross‐sectional associations with physical activity and sedentary time. Methods: Participants were 6009 children and adolescents from 8 studies of the International Children's Accelerometry Database. Physical activity and sedentary time were measured by accelerometer. Metabolic syndrome was defined based on International Diabetes Federation criteria. Logistic regression models adjusted for sex, age and monitor wear time were used to examine the associations between physical activity, sedentary time and the metabolic syndrome in each study and effect estimates were combined using random‐effects meta‐analysis. Results: The overall prevalence of the metabolic syndrome was 2.9%. In crude models, a 10 min increase in moderate‐to‐vigorous intensity physical activity and vigorous‐intensity physical activity were inversely associated with the metabolic syndrome [OR 0.88, 95% CI 0.82‐0.94, OR 0.80, 95% CI 0.70‐0.92]. One hour increase in sedentary time was positively associated with the metabolic syndrome [OR 1.28, 95% CI 1.13‐1.45]. After adjustment for sedentary time, the association between moderate‐to‐vigorous‐intensity physical activity and the metabolic syndrome remained significant [OR 0.91, 95% CI 0.84‐0.99]. Sedentary time was not associated with the metabolic syndrome after adjustment for moderate‐to‐vigorous intensity physical activity [OR 1.14 95% CI 0.96‐1.36]. Conclusions: Physical activity of at least moderate intensity but not sedentary time is independently associated with the metabolic syndrome.

• Ekelund, Ulf; Tarp, Jakob; Steene-Johannessen, Jostein; Hansen, Bjørge Hermann; Jefferis, Barbara & Fagerland, Morten [Show all 20 contributors for this article] (2019). Dose-response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonised meta-analysis. The BMJ. 366. doi: 10.1136/bmj.l4570. Full text in Research Archive Show summary

  Objective: To examine the dose-response associations between accelerometer assessed total physical activity, different intensities of physical activity, and sedentary time and all cause mortality. Design: Systematic review and harmonised meta-analysis. Data sources: PubMed, PsycINFO, Embase, Web of Science, Sport Discus from inception to 31 July 2018. Eligibility criteria: Prospective cohort studies assessing physical activity and sedentary time by accelerometry and associations with all cause mortality and reported effect estimates as hazard ratios, odds ratios, or relative risks with 95% confidence intervals. Data extraction and analysis: Guidelines for meta-analyses and systematic reviews for observational studies and PRISMA guidelines were followed. Two authors independently screened the titles and abstracts. One author performed a full text review and another extracted the data. Two authors independently assessed the risk of bias. Individual level participant data were harmonised and analysed at study level. Data on physical activity were categorised by quarters at study level, and study specific associations with all cause mortality were analysed using Cox proportional hazards regression analyses. Study specific results were summarised using random effects meta-analysis. Main outcome measure: All cause mortality. Results: 39 studies were retrieved for full text review; 10 were eligible for inclusion, three were excluded owing to harmonisation challenges (eg, wrist placement of the accelerometer), and one study did not participate. Two additional studies with unpublished mortality data were also included. Thus, individual level data from eight studies (n=36 383; mean age 62.6 years; 72.8% women), with median follow-up of 5.8 years (range 3.0-14.5 years) and 2149 (5.9%) deaths were analysed. Any physical activity, regardless of intensity, was associated with lower risk of mortality, with a non-linear dose-response. Hazards ratios for mortality were 1.00 (referent) in the first quarter (least active), 0.48 (95% confidence interval 0.43 to 0.54) in the second quarter, 0.34 (0.26 to 0.45) in the third quarter, and 0.27 (0.23 to 0.32) in the fourth quarter (most active). Corresponding hazards ratios for light physical activity were 1.00, 0.60 (0.54 to 0.68), 0.44 (0.38 to 0.51), and 0.38 (0.28 to 0.51), and for moderate-to-vigorous physical activity were 1.00, 0.64 (0.55 to 0.74), 0.55 (0.40 to 0.74), and 0.52 (0.43 to 0.61). For sedentary time, hazards ratios were 1.00 (referent; least sedentary), 1.28 (1.09 to 1.51), 1.71 (1.36 to 2.15), and 2.63 (1.94 to 3.56). Conclusion: Higher levels of total physical activity, at any intensity, and less time spent sedentary, are associated with substantially reduced risk for premature mortality, with evidence of a non-linear dose-response pattern in middle aged and older adults.

• Migueles, Jairo H.; Cadenas-Sanchez, Cristina; Tudor-Locke, Catrine; Löf, Marie; Esteban-Cornejo, Irene & Molina-Garcia, Pablo [Show all 11 contributors for this article] (2019). Comparability of published cut-points for the assessment of physical activity: Implications for data harmonization. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 29(4), p. 566–574. doi: 10.1111/sms.13356. Full text in Research Archive Show summary

  This study aimed to compare estimations of sedentary time (SED) and time spent in physical activity (PA) intensities in children with overweight/obesity across different age‐appropriate cut‐points based on different body‐worn attachment sites and accel-eration metrics. A total of 104 overweight/obese children (10.1 ± 1.1 years old, 43 girls) concurrently wore ActiGraph GT3X+ accelerometers on their right hip and non‐dominant wrist for 7 days (24 hours). Euclidean norm −1 g (ENMO) and activ-ity counts from both vertical axis (VACounts) and vector magnitude (VMCounts) were derived. We calculated estimates of SED and light, moderate, vigorous, and moderate‐to‐vigorous (MVPA) intensity PA using different published cut‐points for children. The prevalence of children meeting the recommended 60 min/d of MVPA was calculated. The time spent in SED and the different PA intensities largely dif-fered across cut‐points based on different attachment sites and acceleration metrics (ie, SED = 11‐252 min/d; light PA = 10‐217 min/d; moderate PA = 1‐48 min/d; vig-orous PA = 1‐35 min/d; MVPA = 4‐66 min/d). Consequently, the prevalence of children meeting the recommended 60 min/d of MVPA varied from 8% to 96% of the study sample. The present study provides a comprehensive comparison between available cut‐points for different attachment and acceleration metrics in children. Furthermore, our data clearly show that it is not possible (and probably will never be) to know the prevalence of meeting the PA guidelines based on accelerometer data since apparent differences range from almost zero to nearly everyone meeting the guidelines.

• Migueles, Jairo H.; Cadenas-Sanchez, Cristina; Rowlands, Alex V.; Henriksson, Pontus; Shiroma, Eric & Acosta, Francisco M. [Show all 13 contributors for this article] (2019). Comparability of accelerometer signal aggregation metrics across placements and dominant wrist cut points for the assessment of physical activity in adults. Scientific Reports. 9(1), p. 1–12. doi: 10.1038/s41598-019-54267-y. Full text in Research Archive Show summary

  Large epidemiological studies that use accelerometers for physical behavior and sleep assessment difer in the location of the accelerometer attachment and the signal aggregation metric chosen. This study aimed to assess the comparability of acceleration metrics between commonly-used body-attachment locations for 24hours, waking and sleeping hours, and to test comparability of PA cut points between dominant and non-dominant wrist. Forty-fve young adults (23 women, 18–41 years) were included and GT3X+accelerometers (ActiGraph, Pensacola, FL, USA) were placed on their right hip, dominant, and non-dominant wrist for 7 days. We derived Euclidean Norm Minus One g (ENMO), Low-pass fltered ENMO (LFENMO), Mean Amplitude Deviation (MAD) and ActiGraph activity counts over 5-second epochs from the raw accelerations. Metric values were compared using a correlation analysis, and by plotting the diferences by time of the day. Cut points for the dominant wrist were derived using Lin’s concordance correlation coefcient optimization in a grid of possible thresholds, using the nondominant wrist estimates as reference. They were cross-validated in a separate sample (N=36, 10 women, 22–30 years). Shared variances between pairs of acceleration metrics varied across sites and metric pairs (range in r2: 0.19–0.97, all p<0.01), suggesting that some sites and metrics are associated, and others are not. We observed higher metric values in dominant vs. non-dominant wrist, thus, we developed cut points for dominant wrist based on ENMO to classify sedentary time (<50mg), light PA (50–110mg), moderate PA (110–440mg) and vigorous PA (≥440mg). Our fndings suggest diferences between dominant and non-dominant wrist, and we proposed new cut points to attenuate these diferences. ENMO and LFENMO were the most similar metrics, and they showed good comparability with MAD. However, counts were not comparable with ENMO, LFENMO and MAD.

• Jones, Paul Remy; Rajalahti, Tarja; Resaland, Geir Kåre; Aadland, Eivind; Steene-Johannessen, Jostein & Anderssen, Sigmund Alfred [Show all 10 contributors for this article] (2019). Associations of physical activity and sedentary time with lipoprotein subclasses in Norwegian schoolchildren: The Active Smarter Kids (ASK) study. Atherosclerosis. ISSN 0021-9150. 288, p. 186–193. doi: 10.1016/j.atherosclerosis.2019.05.023. Full text in Research Archive Show summary

  Background and aims: Physical activity is favourably associated with certain markers of lipid metabolism. The relationship of physical activity with lipoprotein particle profiles in children is not known. Here we examine cross-sectional associations between objectively measured physical activity and sedentary time with serum markers of lipoprotein metabolism. Methods: Our cohort included 880 children (49.0% girls, mean age 10.2 years). Physical activity intensity and time spent sedentary were measured objectively using accelerometers. 30 measures of lipoprotein metabolism were quantified using nuclear magnetic resonance spectroscopy. Multiple linear regression models adjusted for age, sex, sexual maturity and socioeconomic status were used to determine associations of physical activity and sedentary time with lipoprotein measures. Additional models were adjusted for adiposity. Isotemporal substitution models quantified theoretical associations of replacing 30 min of sedentary time with 30 min of moderate- to vigorous-intensity physical activity (MVPA). Results: Time spent in MVPA was associated with a favourable lipoprotein profile independent of sedentary time. There were inverse associations with a number of lipoprotein measures, including most apolipoprotein B-containing lipoprotein subclasses and triglyceride measures, the ratio of total to high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol concentration. There were positive associations with larger HDL subclasses, HDL cholesterol concentration and particle size. Reallocating 30 min of sedentary time to MVPA had broadly similar associations. Sedentary time was only partly and weakly associated with an unfavourable lipoprotein profile. Conclusions: Physical activity of at least moderate-intensity is associated with a favourable lipoprotein profile in schoolchildren, independent of time spent sedentary, adiposity and other confounders.

• Wijndaele, Katrien; White, Thomas; Andersen, Lars Bo; Bugge, Anna; Kolle, Elin & Northstone, Kate [Show all 17 contributors for this article] (2019). Substituting prolonged sedentary time and cardiovascular risk in children and youth: a meta-analysis within the International Children’s Accelerometry database (ICAD). International Journal of Behavioral Nutrition and Physical Activity. 16:96, p. 1–10. doi: 10.1186/s12966-019-0858-6. Full text in Research Archive Show summary

  Background Evidence on the association between sitting for extended periods (i.e. prolonged sedentary time (PST)) and cardio-metabolic health is inconsistent in children. We aimed to estimate the differences in cardio-metabolic health associated with substituting PST with non-prolonged sedentary time (non-PST), light (LIPA) or moderate-to-vigorous physical activity (MVPA) in children. Methods Cross-sectional data from 14 studies (7 countries) in the International Children’s Accelerometry Database (ICAD, 1998–2009) was included. Accelerometry in 19,502 participants aged 3–18 years, together with covariate and outcome data, was pooled and harmonized. Iso-temporal substitution in linear regression models provided beta coefficients (95%CI) for substitution of 1 h/day PST (sedentary time accumulated in bouts > 15 min) with non-PST, LIPA or MVPA, for each study, which were meta-analysed. Results Modelling substitution of 1 h/day of PST with non-PST suggested reductions in standardized BMI, but estimates were > 7-fold greater for substitution with MVPA (− 0.44 (− 0.62; − 0.26) SD units). Only reallocation by MVPA was beneficial for waist circumference (− 3.07 (− 4.47; − 1.68) cm), systolic blood pressure (− 1.53 (− 2.42; − 0.65) mmHg) and clustered cardio-metabolic risk (− 0.18 (− 0.3; − 0.1) SD units). For HDL-cholesterol and diastolic blood pressure, substitution with LIPA was beneficial; however, substitution with MVPA showed 5-fold stronger effect estimates (HDL-cholesterol: 0.05 (0.01; 0.10) mmol/l); diastolic blood pressure: − 0.81 (− 1.38; − 0.24) mmHg). Conclusions Replacement of PST with MVPA may be the preferred scenario for behaviour change, given beneficial associations with a wide range of cardio-metabolic risk factors (including adiposity, HDL-cholesterol, blood pressure and clustered cardio-metabolic risk). Effect estimates are clinically relevant (e.g. an estimated reduction in waist circumference of ≈1.5 cm for 30 min/day replacement). Replacement with LIPA could be beneficial for some of these risk factors, however with substantially lower effect estimates.

• Limb, Elizabeth S.; Ahmad, Shaleen; Cook, Derek G.; Kerry, Sally M.; Ekelund, Ulf & Whincup, Peter H. [Show all 14 contributors for this article] (2019). Measuring change in trials of physical activity interventions: A comparison of self-report questionnaire and accelerometry within the PACE-UP trial 11 Medical and Health Sciences 1117 Public Health and Health Services. International Journal of Behavioral Nutrition and Physical Activity. 16(10). doi: 10.1186/s12966-018-0762-5. Full text in Research Archive Show summary

  Background:Few trials have compared estimates of change in physical activity (PA) levels using self-reported andobjective PA measures when evaluating trial outcomes. The PACE-UP trial offered the opportunity to assess this,using the self-administered International Physical Activity Questionnaire (IPAQ) and waist-worn accelerometry.Methods:The PACE-UP trial (N= 1023) compared usual care (n= 338) with two pedometer-based walkinginterventions, by post (n= 339) or with nurse support (n= 346). Participants wore an accelerometer at baseline and12 months and completed IPAQ for the same 7-day periods. Main outcomes were weekly minutes, all in≥10 minbouts as per UK PA guidelines of: i) accelerometer moderate-to-vigorous PA (Acc-MVPA) ii) IPAQ moderate+vigorousPA (IPAQ-MVPA) and iii) IPAQ walking (IPAQ-Walk). For each outcome, 12 month values were regressed on baseline toestimate change.Results:Analyses were restricted to 655 (64%) participants who provided data on all outcomes at baseline and 12months. Both intervention groups significantly increased their accelerometry MVPA minutes/week compared withcontrol: postal group 42 (95% CI 22, 61), nurse group 43 (95% CI 24, 63). IPAQ-Walk minutes/week also increased: postal57 (95% CI 2, 112), nurse 43 (95% CI -11, 97) but IPAQ-MVPA minutes/week showed non-significant decreases: postal-11 (95% CI -65, 42), nurse -34 (95% CI -87, 19).Conclusions:Our results demonstrate the necessity of using a questionnaire focussing on the activities being altered,aswithIPAQ-Walkquestions.Eventhen,thechangeinPAwasestimatedwithfarlessprecisionthanwithaccelerometry.Accelerometry is preferred to self-report measurement, minimising bias and improving precision when assessing effectsof a walking intervention.Trial registration: ISRCTN,ISRCTN98538934. Registered 2 March 2012.

• Väistö, Juuso; Haapala, Eero A.; Viitasalo, Anna; Schnurr, Theresia M.; Kilpeläinen, Tuomas O. & Karjalainen, Panu [Show all 12 contributors for this article] (2019). Longitudinal associations of physical activity and sedentary time with cardiometabolic risk factors in children. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 29(1), p. 113–123. doi: 10.1111/sms.13315. Full text in Research Archive Show summary

  Background: There are few prospective studies on the associations of changes in objectively measured vigorous physical activity (VPA∆), moderate‐to‐vigorous physical activity (MVPA∆), light physical activity (LPA∆), and sedentary time (ST∆) with changes in cardiometabolic risk factors (∆) in children. We therefore investi-gated these relationships among children.Methods: The participants were a population sample of 258 children aged 6‐8 years followed for 2 years. We assessed PA and ST by a combined heart rate and move-ment sensor; computed continuous age‐ and sex‐adjusted z‐scores for waist circum-ference, blood pressure, and fasting insulin, glucose, triglycerides, and high‐density lipoprotein (HDL) cholesterol; and constructed a cardiometabolic risk score (CRS) of these risk factors. Data were analyzed using linear regression models adjusted for age, sex, the explanatory and outcome variables at baseline, and puberty.Results: VPA∆ associated inversely with CRS∆ (β = −0.209, P = 0.001), body fat percentage (BF%)∆ (β = −0.244, P = 0.001), insulin∆ (β = −0.220, P = 0.001), and triglycerides∆ (β = −0.164, P = 0.012) and directly with HDL cholesterol∆ (β = 0.159, P = 0.023). MVPA∆ associated inversely with CRS∆ (β = −0.178, P = 0.012), BF%∆ (β = −0.298, P = <0.001), and insulin∆ (β = −0.213, P = 0.006) and directly with HDL cholesterol∆ (β = 0.184, P = 0.022). LPA∆ only associated negatively with CRS∆ (β = −0.163, P = 0.032). ST∆ associated directly with CRS∆ (β = 0.218, P = 0.003), BF%∆ (β = 0.212, P = 0.016), and insulin∆ (β = 0.159, P = 0.049).Conclusions: Increased VPA and MVPA and decreased ST were associated with reduced overall cardiometabolic risk and major individual risk factors. Change in LPA had weaker associations with changes in these cardiometabolic risk factors. Our findings suggest that increasing at least moderate‐intensity PA and decreasing ST decrease cardiometabolic risk in children.

• Jones, Paul Remy & Ekelund, Ulf (2019). Physical activity in the prevention of weight gain: the impact of measurement and interpretation of associations. Current Obesity Reports. 8(2), p. 66–76. doi: 10.1007/s13679-019-00337-1. Full text in Research Archive Show summary

  Purpose of Review: To what extent do different methods of physical activity measurement and statistical analysis influence the reported associations between physical activity and weight gain? Recent Findings: The obesity epidemic has led to a focus on lifestyle approaches to the prevention of weight gain. Physical activity is one such approach. A number of studies have reported beneficial associations between higher levels of physical activity and weight gain at the population level. However, limitations of physical activity measurement and analytical models in some of these studies are likely to have resulted in overestimation of the strength of association. Summary: Understanding the limitations of assessment methods and analytical models used in epidemiological research should facilitate more realistic appraisal for physical activity to prevent weight gain at the population level and inform approaches to future research.

• Bernhardsen, Guro Pauck; Stensrud, Trine; Nystad, Wenche; Dalene, Knut Eirik; Kolle, Elin & Ekelund, Ulf (2019). Early life risk factors for childhood obesity—Does physical activity modify the associations? The MoBa cohort study. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 29(10), p. 1636–1646. doi: 10.1111/sms.13504. Full text in Research Archive Show summary

  Objectives: High maternal pre‐pregnancy body mass index (BMI), high birth weight, and rapid infant weight gain are associated with increased risk of childhood obesity. We examined whether moderate‐to‐vigorous physical activity (MVPA) or vigorous physical activity (VPA) in 9‐ to 12‐year‐olds modified the associations between these early life risk factors and subsequent body composition and BMI. Methods: We used data from a sub‐cohort of the Norwegian Mother and Child Cohort Study (MoBa), including 445 children with available data on accelerometer assessed physical activity (PA). All participants had data on BMI, 186 of them provided data on body composition (dual energy X‐ray absorptiometry (DXA)). We used multiple regression analyses to examine the modifying effect of PA by including interaction terms. Results: Maternal pre‐pregnancy BMI and infant weight gain were more strongly related to childhood body composition in boys than in girls. Higher VPA attenuated the association between maternal pre‐pregnancy BMI and BMI in boys (low VPA: B = 0.32, 95% CI = 0.22, 0.41; high VPA B = 0.22, 95% CI = 0.12, 0.31). Birth weight was unrelated to childhood body composition, and there was no effect modification by PA. PA attenuated the associations between infant weight gain and childhood fat mass (low MVPA: B = 2.32, 95% CI = 0.48, 4.17; high MVPA: B = 1.00, 95% CI = 0.10, 1.90) and percent fat (low MVPA: B = 3.35, 95% CI = 0.56, 6.14; high MVPA: B = 1.41, 95% CI = −0.06, 2.87) in boys, but not girls. Conclusion: Findings from this study suggest that MVPA and VPA may attenuate the increased risk of an unfavorable body composition and BMI due to high maternal pre‐pregnancy BMI and rapid infant weight gain in boys, but not in girls.

• Stamatakis, Emmanuel; Gale, Joanne; Bauman, Adrian; Ekelund, Ulf; Hamer, Mark & Ding, Ding (2019). Sitting Time, Physical Activity, and Risk of Mortality in Adults. Journal of the American College of Cardiology. ISSN 0735-1097. 73(16), p. 2062–2072. doi: 10.1016/j.jacc.2019.02.031. Full text in Research Archive Show summary

  BACKGROUND It is unclear what level of moderate to vigorous intensity physical activity (MVPA) offsets the healthrisks of sitting.OBJECTIVESThe purpose of this study was to examine the joint and stratified associations of sitting and MVPA withall-cause and cardiovascular disease (CVD) mortality, and to estimate the theoretical effect of replacing sitting time withphysical activity, standing, and sleep.METHODSA longitudinal analysis of the 45 and Up Study calculated the multivariable-adjusted hazard ratios (HRs) ofsitting for each sitting-MVPA combination group and within MVPA strata. Isotemporal substitution modeling estimatedthe per-hour HR effects of replacing sitting.RESULTSA total of 8,689 deaths (1,644 due to CVD) occurred among 149,077 participants over an 8.9-year (median)follow-up. There was a statistically significant interaction between sitting and MVPA only for all-cause mortality. Sittingtime was associated with both mortality outcomes in a nearly dose-response manner in the least active groupsreporting<150 MVPA min/week. For example, among those reporting no MVPA, the all-cause mortality HR comparingthe most sedentary (>8 h/day) to the least sedentary (<4 h/day) groups was 1.52 (95% confidence interval: 1.13 to 2.03).There was inconsistent and weak evidence for elevated CVD and all-cause mortality risks with more sitting among thosemeeting the lower (150 to 299 MVPA min/week) or upper ($300 MVPA min/week) limits of the MVPA recommendation.Replacing sitting with walking and MVPA showed stronger associations among high sitters (>6 sitting h/day) where, forexample, the per-hour CVD mortality HR for sitting replaced with vigorous activity was 0.36 (95% confidence interval:0.17 to 0.74).CONCLUSIONSSitting is associated with all-cause and CVD mortality risk among the least physically active adults;moderate-to-vigorous physical activity doses equivalent to meeting the current recommendations attenuate oreffectively eliminate such associations. (J Am Coll Cardiol 2019;73:2062–72) © 2019 The Authors. Published byElsevier on behalf of the American College of Cardiology Foundation. This is an open access article under theCC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

• Harris, Tess; Limb, Elizabeth S.; Hosking, Fay J.; Carey, Iain; DeWilde, Steve & Furness, Cheryl [Show all 17 contributors for this article] (2019). Effect of pedometer-based walking interventions on long-term health outcomes: Prospective 4-year follow-up of two randomised controlled trials using routine primary care data. PLoS Medicine. ISSN 1549-1277. 16(6). doi: 10.1371/journal.pmed.1002836. Full text in Research Archive Show summary

  Background: Data are lacking from physical activity (PA) trials with long-term follow-up of both objectively measured PA levels and robust health outcomes. Two primary care 12-week pedometer-based walking interventions in adults and older adults (PACE-UP and PACE-Lift) found sustained objectively measured PA increases at 3 and 4 years, respectively. We aimed to evaluate trial intervention effects on long-term health outcomes relevant to walking interventions, using routine primary care data. Methods and findings: Randomisation was from October 2012 to November 2013 for PACE-UP participants from seven general (family) practices and October 2011 to October 2012 for PACE-Lift participants from three practices. We downloaded primary care data, masked to intervention or control status, for 1,001 PACE-UP participants aged 45–75 years, 36% (361) male, and 296 PACE-Lift participants, aged 60–75 years, 46% (138) male, who gave written informed consent, for 4-year periods following randomisation. The following new events were counted for all participants, including those with preexisting diseases (apart from diabetes, for which existing cases were excluded): nonfatal cardiovascular, total cardiovascular (including fatal), incident diabetes, depression, fractures, and falls. Intervention effects on time to first event post-randomisation were modelled using Cox regression for all outcomes, except for falls, which used negative binomial regression to allow for multiple events, adjusting for age, sex, and study. Absolute risk reductions (ARRs) and numbers needed to treat (NNTs) were estimated. Data were downloaded for 1,297 (98%) of 1,321 trial participants. Event rates were low (<20 per group) for outcomes, apart from fractures and falls. Cox hazard ratios for time to first event post-randomisation for interventions versus controls were nonfatal cardiovascular 0.24 (95% confidence interval [CI] 0.07–0.77, p = 0.02), total cardiovascular 0.34 (95% CI 0.12–0.91, p = 0.03), diabetes 0.75 (95% CI 0.42–1.36, p = 0.34), depression 0.98 (95% CI 0.46–2.07, p = 0.96), and fractures 0.56 (95% CI 0.35–0.90, p = 0.02). Negative binomial incident rate ratio for falls was 1.07 (95% CI 0.78–1.46, p = 0.67). ARR and NNT for cardiovascular events were nonfatal 1.7% (95% CI 0.5%–2.1%), NNT = 59 (95% CI 48–194); total 1.6% (95% CI 0.2%–2.2%), NNT = 61 (95% CI 46–472); and for fractures 3.6% (95% CI 0.8%–5.4%), NNT = 28 (95% CI 19–125). Main limitations were that event rates were low and only events recorded in primary care records were counted; however, any underrecording would not have differed by intervention status and so should not have led to bias. Conclusions: Routine primary care data used to assess long-term trial outcomes demonstrated significantly fewer new cardiovascular events and fractures in intervention participants at 4 years. No statistically significant differences between intervention and control groups were demonstrated for other events. Short-term primary care pedometer-based walking interventions can produce long-term health benefits and should be more widely used to help address the public health inactivity challenge.

• Bielemann, Renata M.; LaCroix, Andrea Z.; Bertoldi, Andréa D.; Tomasi, Elaine; Demarco, Flávio F. & Gonzalez, Maria Christina [Show all 12 contributors for this article] (2019). Objectively Measured Physical Activity Reduces the Risk of Mortality among Brazilian Older Adults. Journal of The American Geriatrics Society. ISSN 0002-8614. 16, p. 137–146. doi: 10.1111/jgs.16180. Full text in Research Archive Show summary

  OBJECTIVES: Use of objectively measured physical activity(PA) in older adults to assess relationship between PA andrisk of all-causes mortality is scarce. This study evaluatedthe associations of PA based on accelerometry and a ques-tionnaire with the risk of mortality among older adultsfrom a city in Southern Brazil. DESIGN: A cohort study. SETTING: Urban area of Pelotas, Southern Brazil. PARTICIPANTS: A representative sample of older adults(≥60 y) from Pelotas, enrolled in 2014. MEASUREMENTS: Overall physical activity (mg), lightphysical activity (LPA), and moderate to vigorous physicalactivity (MVPA) were estimated by raw accelerometer data.The International Physical Activity Questionnaire estimated lei-sure time and commuting PA. Hazard ratios (excluding deathsin the first 6 mo) stratified by sex were estimated by Coxregression analysis considering adjustment for confounders.RESULTS: From the 1451 older adults interviewed in 2014,145 died (10%) after a follow-up of an average 2.6 years.Men and women in the highest tertile of overall PA had onaverage a 77% and 92% lower risk of mortality than theirless active counterparts (95% confidence interval [CI] =.06-.84 and 95% CI = .01-.65, respectively). The highest ter-tile of LPA was also related to a lower risk of mortality inindividuals of both sexes (74% and 91% lower risk amongmen and women, respectively). MVPA statistically reducedthe risk of mortality only among women (hazard ratio[HR] = .30 and HR = .07 in the second and third tertiles).Self-reported leisure-time PA was statistically associated witha lower risk of mortality only among men. Women in thehighest tertiles of commuting PA showed a lower risk of mor-tality than those in the reference group. CONCLUSION: Accelerometry-based PA was associatedwith a lower risk of mortality among Brazilian older adults.Older individuals should practice any type of PA.

• Bielemann, Renata M; Ramires, Virgílio Viana; Wehrmeister, Fernando César; Goncalves, Helen; Assuncao, Maria Cecília Formoso & Ekelund, Ulf [Show all 7 contributors for this article] (2019). Is vigorous-intensity physical activity required for improving bone mass in adolescence? Findings from a Brazilian birth cohort. Osteoporosis International. ISSN 0937-941X. 30. doi: 10.1007/s00198-019-04862-6. Full text in Research Archive Show summary

  Summary: The association between moderate and vigorous physical activity throughout adolescence and areal bone density (aBMD) at 18 years of age was evaluated. Vigorous-intensity physical activity at 11, 15, and 18 years was associated with aBMD in early adulthood, especially in boys. Cross-sectional analyses showed a positive association between moderate physical activity and aBMD. Introduction: To evaluate independent associations of moderate and vigorous physical activity (MPA, VPA) across adolescence with areal bone mineral density (aBMD). Methods: Physical activity (PA) was assessed at 11, 15, and 18 years of age by self-report and at 18 years by accelerometry in the 1993 Pelotas Birth Cohort Study. Time spent in MPA and VPA was determined using metabolic equivalents and specific cutoffs based on raw acceleration. Lumbar spine and femoral neck aBMD were measured by DXA at 18 years. Statistical analyses evaluated the association of MPA and VPA with aBMD, after adjusting for skin color, asset index, current height and age at menarche, and peak strain score (based on ground reaction forces of PA). Results: Lumbar spine and femoral neck aBMD were available for 3947 (49.9% of boys) and 3960 (49.6% of boys) individuals, respectively. Time spent in MPA at 11 and 15 years was not associated with aBMD. VPA at all time points was positively related to both lumbar spine and femoral neck aBMD in boys. Results were consistent for objectively measured VPA. Girls who achieved 75+ minutes/week of VPA in at least two follow-ups showed higher aBMD at 18 years of age. Boys who reached 75+ minutes/week of VPA at all follow-ups had on average 0.117 g/cm2 (95% CI: 0.090; 0.144) higher femoral neck aBMD than those who never achieved this threshold. Conclusions: Self-reported VPA but not MPA throughout adolescence was associated with aBMD. Recommendation for PA in young people should consider the importance of VPA.

• Ding, Ding; Varela, Andrea Ramirez; Bauman, Adrian E.; Ekelund, Ulf; Lee, I-Min & Heath, Gregory [Show all 9 contributors for this article] (2019). Towards better evidence-informed global action: Lessons learnt from the Lancet series and recent developments in physical activity and public health. British Journal of Sports Medicine. ISSN 0306-3674. 54(8), p. 462–468. doi: 10.1136/bjsports-2019-101001. Full text in Research Archive Show summary

  In the past few decades, the field of physical activity has grown and evolved in scope, depth, visibility and impact around the world. Global progress has been observed in research and practice in physical activity regarding surveillance, health outcomes, correlates/determinants, interventions, translation and policy. The 2012 and 2016 Lancet series on physical activity provide some of the most comprehensive global analysis on various topics within physical activity. Based on the Lancet series and other key developments in the field, literature searches, and expert group meetings and consultation, we provide a global summary on the progress of, gaps in and future directions for physical activity research in the following areas: (1) surveillance and trends, (2) correlates and determinants, (3) health outcomes and (4) interventions, programmes and policies. Besides lessons learnt within each specific area, several recommendations are shared across areas of research, including improvement in measurement, applying a global perspective with a growing emphasis on low-income and middle-income countries, improving inclusiveness and equity in research, making translation an integral part of research for real-world impact, taking an ‘upstream’ public health approach, and working across disciplines and sectors to co-design research and co-create solutions. We have summarised lessons learnt and recommendations for future research as ‘roadmaps’ in progress to encourage moving the field of physical activity towards achieving population-level impact globally.

• Nordlund, David; Engblom, Henrik; Bonnet, Jean-Louis; Hansen, Henrik Steen; Atar, Dan & Erlinge, David [Show all 10 contributors for this article] (2019). Gender but not diabetes, hypertension or smoking affects infarct evolution in ST-elevation myocardial infarction patients - Data from the CHILL-MI, MITOCARE and SOCCER trials. BMC Cardiovascular Disorders. 19(1). doi: 10.1186/s12872-019-1139-7. Full text in Research Archive Show summary

  Background Infarct evolution rate and response to acute reperfusion therapy may differ between patients, which is important to consider for accurate management and treatment of patients with ST-elevation myocardial infarction (STEMI). The aim of this study was therefore to investigate the association of infarct size and myocardial salvage with gender, smoking status, presence of diabetes or history of hypertension in a cohort of STEMI-patients. Methods Patients (n = 301) with first-time STEMI from the three recent multi-center trials (CHILL-MI, MITOCARE and SOCCER) underwent cardiac magnetic resonance (CMR) imaging to determine myocardium at risk (MaR) and infarct size (IS). Myocardial salvage index (MSI) was calculated as MSI = 1-IS/MaR. Pain to balloon time, culprit vessel, trial treatments, age, TIMI grade flow and collateral flow by Rentrop grading were included as explanatory variables in the statistical model. Results Women (n = 66) had significantly smaller MaR (mean difference: 5.0 ± 1.5% of left ventricle (LV), p < 0.01), smaller IS (mean difference: 5.1 ± 1.4% of LV, p = 0.03), and larger MSI (mean difference: 9.6 ± 2.8% of LV, p < 0.01) compared to men (n = 238). These differences remained significant when adjusting for other explanatory variables. There were no significant effects on MaR, IS or MSI for diabetes, hypertension or smoking. Conclusions Female gender is associated with higher myocardial salvage and smaller infarct size suggesting a pathophysiological difference in infarct evolution between men and women.

• Silva, Shana Ginar da; Evenson, Kelly R.; Ekelund, Ulf; Silva, Inácio Crochemore Mohnsam da; Domingues, Marlos Rodrigues & Silva, Bruna Gonçalves Cordeiro da [Show all 9 contributors for this article] (2019). How many days are needed to estimate wrist-worn accelerometry-assessed physical activity during the second trimester in pregnancy? PLOS ONE. 14(6). doi: 10.1371/journal.pone.0211442. Full text in Research Archive Show summary

  Background: Objective methods to measure physical activity (PA) can lead to better cross-cultural comparisons, monitoring temporal PA trends, and measuring the effect of interventions. However, when applying this technology in field-work, the accelerometer data processing is prone to methodological issues. One of the most challenging issues relates to standardizing total wear time to provide reliable data across participants. It is generally accepted that at least 4 complete days of accelerometer wear represent a week for adults. It is not known if this same assumption holds true for pregnant women. Aim: We assessed the optimal number of days needed to obtain reliable estimates of overall PA and moderate-to-vigorous physical activity (MVPA) during the 2nd trimester in pregnancy using a raw triaxial wrist-worn accelerometer. Methods: Cross-sectional analyses were carried out in the antenatal wave of the 2015 Pelotas (Brazil) Birth Cohort Study. Participants wore the wrist ActiGraph wGT3X-BT accelerometer for seven consecutive days. The daily average acceleration, which indicated overall PA, was measured as milli-g (mg), and time spent in MVPA (minutes/day) was analyzed in 5-minute bouts. ANOVA and Kruskal-Wallis tests were used to compare variability across days of the week. Bland-Altman plots and the Spearman-Brown Prophecy Formula were applied to determine the reliability coefficient associated with one to seven days of measurement. Results: Among 2,082 pregnant women who wore the accelerometer for seven complete days, overall and MVPA were lower on Sundays compared to other days of the week. Reliability of > = 0.80 to evaluate overall PA was reached with at least three monitoring days, whereas seven days were needed to estimate reliable measures of MVPA. Conclusions: Our findings indicate that obtaining one week of accelerometry in adults is appropriate for pregnant women, particularly to obtain differences on weekend days and reliably estimate overall PA and MVPA.

• Veijalainen, Aapo; Haapala, Eero A.; Väistö, Juuso; Leppänen, Marja H.; Lintu, Niina & Tompuri, Tuomo [Show all 12 contributors for this article] (2019). Associations of physical activity, sedentary time, and cardiorespiratory fitness with heart rate variability in 6- to 9-year-old children: the PANIC study. European Journal of Applied Physiology. ISSN 1439-6319. 119(11-12), p. 2487–2498. doi: 10.1007/s00421-019-04231-5. Full text in Research Archive Show summary

  Purpose: To study the associations of physical activity (PA), sedentary time (ST), and cardiorespiratory fitness (CRF) with heart rate variability (HRV) in children. Methods: The participants were a population sample of 377 children aged 6–9 years (49% boys). ST, light PA (LPA), moderate PA (MPA), vigorous PA (VPA), and moderate-to-vigorous PA (MVPA), and PA energy expenditure (PAEE) were assessed using a combined heart rate and movement sensor, maximal power output per kilograms of lean body mass as a measure of CRF by maximal cycle ergometer exercise test, and HRV variables (SDNN, RMSSD, LF, and HF) using 5 min resting electrocardiography. Data were analysed by linear regression adjusted for years from peak height velocity. Results: In boys, ST was inversely associated (β = − 0.185 to − 0.146, p ≤ 0.049) and MVPA, VPA, PAEE, and CRF were directly associated (β = 0.147 to 0.320, p ≤ 0.048) with HRV variables. CRF was directly associated with all HRV variables and PAEE was directly associated with RMSSD after mutual adjustment for ST, PAEE, and CRF (β = 0.169 to 0.270, p ≤ 0.046). In girls, ST was inversely associated (β = − 0.382 to − 0.294, p < 0.001) and LPA, MPA, VPA, MVPA, and PAEE were directly associated with HRV variables (β = 0.144 to 0.348, p ≤ 0.049). After mutual adjustment for ST, PAEE, and CRF, only the inverse associations of ST with HRV variables remained statistically significant. Conclusions: Higher ST and lower PA and CRF were associated with poorer cardiac autonomic nervous system function in children. Lower CRF in boys and higher ST in girls were the strongest correlates of poorer cardiac autonomic function.

• Hansen, Bjørge Hermann; Anderssen, Sigmund Alfred; Andersen, Lars Bo; Hildebrand, Maria; Kolle, Elin & Steene-Johannessen, Jostein [Show all 14 contributors for this article] (2018). Cross-sectional associations of reallocating time between sedentary and active behaviours on cardiometabolic risk factors in young people : an International Children’s Accelerometry Database (ICAD) analysis. Sports Medicine. ISSN 0112-1642. 48(10), p. 2401–2412. doi: 10.1007/s40279-018-0909-1. Full text in Research Archive Show summary

  Introduction Sedentary time and time spent in various intensity-specific physical activity are co-dependent, and increasing time spent in one behaviour requires decreased time in another. Objective The aim of the present study was to examine the theoretical associations with reallocating time between categories of intensities and cardiometabolic risk factors in a large and heterogeneous sample of children and adolescents. Methods We analysed pooled data from 13 studies comprising 18,200 children and adolescents aged 4–18 years from the International Children’s Accelerometry Database (ICAD). Waist-mounted accelerometers measured sedentary time, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA). Cardiometabolic risk factors included waist circumference (WC), systolic blood pressure (SBP), fasting high- and low-density lipoprotein cholesterol (HDL-C and LDL-C), triglycerides, insulin, and glucose. Associations of reallocating time between the various intensity categories with cardiometabolic risk factors were explored using isotemporal substitution modelling. Results Replacing 10 min of sedentary time with 10 min of MVPA showed favourable associations with WC, SBP, LDL-C, insulin, triglycerides, and glucose; the greatest magnitude was observed for insulin (reduction of 2–4%), WC (reduction of 0.5–1%), and triglycerides (1–2%). In addition, replacing 10 min of sedentary time with an equal amount of LPA showed beneficial associations with WC, although only in adolescents. Conclusions Replacing sedentary time and/or LPA with MVPA in children and adolescents is favourably associated with most markers of cardiometabolic risk. Efforts aimed at replacing sedentary time with active behaviours, particularly those of at least moderate intensity, appear to be an effective strategy to reduce cardiometabolic risk in young people.

• Harris, Tess; Kerry, Sally M.; Limb, Elizabeth S.; Furness, Cheryl; Wahlich, Charlotte & Victor, Christina R. [Show all 15 contributors for this article] (2018). Physical activity levels in adults and older adults 3–4 years after pedometer-based walking interventions: Long-term follow-up of participants from two randomised controlled trials in UK primary care. PLoS Medicine. ISSN 1549-1277. 15(3). doi: 10.1371/journal.pmed.1002526. Full text in Research Archive Show summary

  Background: Physical inactivity is an important cause of noncommunicable diseases. Interventions can increase short-term physical activity (PA), but health benefits require maintenance. Few interventions have evaluated PA objectively beyond 12 months. We followed up two pedometer interventions with positive 12-month effects to examine objective PA levels at 3–4 years. Methods and findings: Long-term follow-up of two completed trials: Pedometer And Consultation Evaluation-UP (PACE-UP) 3-arm (postal, nurse support, control) at 3 years and Pedometer Accelerometer Consultation Evaluation-Lift (PACE-Lift) 2-arm (nurse support, control) at 4 years post-baseline. Randomly selected patients from 10 United Kingdom primary care practices were recruited (PACE-UP: 45–75 years, PACE-Lift: 60–75 years). Intervention arms received 12-week walking programmes (pedometer, handbooks, PA diaries) postally (PACE-UP) or with nurse support (PACE-UP, PACE-Lift). Main outcomes were changes in 7-day accelerometer average daily step counts and weekly time in moderate-to-vigorous PA (MVPA) in ≥10-minute bouts in intervention versus control groups, between baseline and 3 years (PACE-UP) and 4 years (PACE-Lift). PACE-UP 3-year follow-up was 67% (681/1,023) (mean age: 59, 64% female), and PACE-Lift 4-year follow-up was 76% (225/298) (mean age: 67, 53% female). PACE-UP 3-year intervention versus control comparisons were as follows: additional steps/day postal +627 (95% CI: 198–1,056), p = 0.004, nurse +670 (95% CI: 237–1,102), p = 0.002; total weekly MVPA in bouts (minutes/week) postal +28 (95% CI: 7–49), p = 0.009, nurse +24 (95% CI: 3–45), p = 0.03. PACE-Lift 4-year intervention versus control comparisons were: +407 (95% CI: −177–992), p = 0.17 steps/day, and +32 (95% CI: 5–60), p = 0.02 minutes/week MVPA in bouts. Neither trial showed sedentary or wear-time differences. Main study limitation was incomplete follow-up; however, results were robust to missing data sensitivity analyses. Conclusions: Intervention participants followed up from both trials demonstrated higher levels of objectively measured PA at 3–4 years than controls, similar to previously reported 12-month trial effects. Pedometer interventions, delivered by post or with nurse support, can help address the public health physical inactivity challenge.

• Cureau, Felipe Vogt; Sparrenberger, Karen; Bloch, Katia Vergetti; Ekelund, Ulf & Schaan, Beatriz D. (2018). Associations of multiple unhealthy lifestyle behaviors with overweight/obesity and abdominal obesity among Brazilian adolescents: A country-wide survey. NMCD. Nutrition Metabolism and Cardiovascular Diseases. ISSN 0939-4753. 28(7), p. 765–774. doi: 10.1016/j.numecd.2018.04.012. Full text in Research Archive Show summary

  Background and Aims: Physical inactivity, unhealthy diet, smoking and heavy drinking are four key unhealthy lifestyle behaviors (ULB) that may influence body weight and obesity development. More recently, sedentary time has been recognized as another potentially emerging ULB related to obesity. We therefore investigated the association of multiple ULB with overweight/obesity and abdominal obesity among Brazilian adolescents. Methods and Results: This cross-sectional study involved 62,063 students (12–17 years). Physical inactivity, high screen time, low fiber intake, binge drinking and smoking were self-reported and combined to a ULB risk score, ranging from zero to five. Participants were classified as overweight/obese or with abdominal obesity using sex and age-specific cut-off points for BMI and waist circumference, respectively. Poisson regression models were used to examine the associations between ULB with overweight/obesity and abdominal obesity, adjusted for socio-demographic variables. Overall, 2.3%, 18.9%, 43.9%, 32.3% and 2.6% of participants reported zero, one, two, three and four/five ULB, respectively. Higher ULB risk score was associated with overweight/obesity and abdominal obesity in a dose–response gradient. Among 32 possible combinations of ULB, the three most prevalent combinations (physical inactivity + low fiber intake; high screen time + low fiber intake; physical inactivity + high screen time + low fiber intake) were positively associated with general and abdominal obesity. Conclusions: Our findings suggest a synergistic relationship between ULB and general and abdominal obesity. Preventive efforts targeting combined ULB should be sought to reduce the prevalence of general and abdominal obesity in Brazilian youth.

• Kerry, Sally M.; Morgan, Katy E; Limb, Elizabeth; Cook, Derek G.; Furness, Cheryl & Carey, Iain [Show all 15 contributors for this article] (2018). Interpreting population reach of a large, successful physical activity trial delivered through primary care. BMC Public Health. 18(1). doi: 10.1186/s12889-018-5034-4. Full text in Research Archive Show summary

  Background: Failure to include socio-economically deprived or ethnic minority groups in physical activity (PA) trials may limit representativeness and could lead to implementation of interventions that then increase health inequalities. Randomised intervention trials often have low recruitment rates and rarely assess recruitment bias. A previous trial by the same team using similar methods recruited 30% of the eligible population but was in an affluent setting with few non-white residents and was limited to those over 60 years of age. Methods: PACE-UP is a large, effective, population-based walking trial in inactive 45-75 year-olds that recruited through seven London general practices. Anonymised practice demographic data were available for all those invited, enabling investigation of inequalities in trial recruitment. Non-participants were invited to complete a questionnaire. Results: From 10,927 postal invitations, 1150 (10.5%) completed baseline assessment. Participation rate ratios (95% CI), adjusted for age and gender as appropriate, were lower in men 0.59 (0.52, 0.67) than women, in those under 55 compared with those ≥65, 0.60 (0.51, 0.71), in the most deprived quintile compared with the least deprived 0.52 (0.39, 0.70) and in Asian individuals compared with whites 0.62 (0. 50, 0.76). Black individuals were equally likely to participate as white individuals. Participation was also associated with having a co-morbidity or some degree of health limitation. The most common reasons for non-participation were considering themselves as being too active or lack of time. Conclusions: Conducting the trial in this diverse setting reduced overall response, with lower response in socio-economically deprived and Asian sub-groups. Trials with greater reach are likely to be more expensive in terms of recruitment and gains in generalizability need to be balanced with greater costs. Differential uptake of successful trial interventions may increase inequalities in PA levels and should be monitored.

• Silva, Shana Ginar da; Evenson, Kelly R.; Silva, Inácio Crochemore da; Mendes, Márcio A; Domingues, Marlos Rodrigues & Silveira, Mariângela Freitas da [Show all 9 contributors for this article] (2018). Correlates of accelerometer-assessed physical activity in pregnancy?The 2015 Pelotas (Brazil) Birth Cohort Study. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 28(8), p. 1934–1945. doi: 10.1111/sms.13083. Full text in Research Archive Show summary

  Objective methods to measure physical activity (PA) have become available and widely used given the high degree of precision to evaluate PA. However, few studies have used accelerometers to measure PA during pregnancy, especially in low‐ and middle‐income countries. We assessed overall PA, moderate, vigorous, and moderate‐to‐vigorous physical activity (MVPA) objectively measured among pregnant women and their correlates in a population‐based study. PA was assessed for seven consecutive days using a raw triaxial wrist‐worn accelerometer in women interviewed around 16 and 24 weeks of gestation in the 2015 Pelotas (Brazil) Birth Cohort Study. The average acceleration, which expresses overall PA, was presented in milli‐g (1 mg = 0.001 g), and average time (min/day) spent in MVPA (>100 mg) was also analyzed in 5‐ and 10‐min bouts. Analyses were performed using linear regression. In total, 2317 women were included in the analyses. Overall PA was 27.6 mg. Pregnant women spent on average 14 min/day in MVPA and 0.4 min in vigorous PA. Time spent in MVPA and total PA were inversely associated with years in school and income, and were lower among women receiving advice to not exercise. MVPA was also inversely associated with age, lower among women living with a partner, and higher among non‐white women. The study indicated low levels of PA among pregnant women. The identified correlates may provide a framework to better understand factors influencing PA during pregnancy and thus inform future interventions.

• Bielemann, Renata M; Vaz, Juliana dos S; Domingues, Marlos Rodrigues; Matijasevich, Alícia; Santos, Ina S & Ekelund, Ulf [Show all 7 contributors for this article] (2018). Are consumption of dairy products and physical activity independently related to bone mineral density of 6-year-old children? Longitudinal and cross-sectional analyses in a birth cohort from Brazil. Public Health Nutrition (PHN). ISSN 1368-9800. 21(14), p. 2654–2664. doi: 10.1017/S1368980018001258. Full text in Research Archive Show summary

  Objective: To evaluate cross-sectional and longitudinal associations of consumption of dairy products and physical activity (PA) with bone mineral density (BMD). Design: Cohort study with children from the 2004 Pelotas (Brazil) Birth Cohort. Setting: Pelotas, a medium-sized Brazilian city. Subjects: The study started in 2004 and mothers/children were interviewed/measured periodically from birth to age 6 years. PA was measured by maternal proxy at 4 and 6 years and by accelerometry at 6 years. Consumption of dairy products was measured using 24 h food recall (at 4 years) and FFQ (at 6 years). Total-body and lumbar-spine BMD (g/cm2) were measured by dual-energy X-ray absorptiometry. Results: At 6 years, BMD was measured in 3444 children and 2636 children provided data on objectively measured PA by accelerometry. Consumption of dairy products at 4 years was associated with higher lumbar-spine BMD at 6 years in boys, while current consumption was positively associated with BMD in both sexes (P < 0·001). PA assessed by maternal report at 4 and 6 years of age was associated with higher BMD at 6 years in boys. PA assessed by accelerometry was positively related to total-body and lumbar-spine BMD in boys and lumbar-spine BMD in girls. We did not find evidence for an interaction between PA and consumption of dairy products on BMD. Conclusions: We observed positive and independent longitudinal and cross-sectional associations between consumption of dairy products and PA with BMD in the total body and at the lumbar spine in young children.

• Ariansen, Inger Kristine Holtermann & Ekelund, Ulf (2018). Fysisk aktivitet. In Grøholt, Else Karin; Bøhler, Linn & Hånes, Hanna (Ed.), Folkehelserapporten - Helsetilstanden i Norge. Folkehelseinstituttet. Full text in Research Archive
• Stamatakis, Emmanuel; Ekelund, Ulf; Ding, Ding; Hamer, Mark; Bauman, Adrian & Lee, I-Min (2018). Is the time right for quantitative public health guidelines on sitting? A narrative review of sedentary behaviour research paradigms and findings. British Journal of Sports Medicine. ISSN 0306-3674. doi: 10.1136/bjsports-2018-099131. Full text in Research Archive Show summary

  Sedentary behaviour (SB) has been proposed as an ‘independent’ risk factor for chronic disease risk, attracting much research and media attention. Many countries have included generic, non-quantitative reductions in SB in their public health guidelines and calls for quantitative SB targets are increasing. The aim of this narrative review is to critically evaluate key evidence areas relating to the development of guidance on sitting for adults. We carried out a non-systematic narrative evidence synthesis across seven key areas: (1) definition of SB, (2) independence of sitting from physical activity, (3) use of television viewing as a proxy of sitting, (4) interpretation of SB evidence, (5) evidence on ‘sedentary breaks’, (6) evidence on objectively measured sedentary SB and mortality and (7) dose response of sitting and mortality/cardiovascular disease. Despite research progress, we still know little about the independent detrimental health effects of sitting, and the possibility that sitting is mostly the inverse of physical activity remains. Unresolved issues include an unclear definition, inconsistencies between mechanistic and epidemiological studies, over-reliance on surrogate outcomes, a very weak epidemiological evidence base to support the inclusion of ‘sedentary breaks’ in guidelines, reliance on self-reported sitting measures, and misinterpretation of data whereby methodologically inconsistent associations are claimed to be strong evidence. In conclusion, public health guidance requires a consistent evidence base but this is lacking for SB. The development of quantitative SB guidance, using an underdeveloped evidence base, is premature; any further recommendations for sedentary behaviour require development of the evidence base and refinement of the research paradigms used in the field.

• Dalene, Knut Eirik; Anderssen, Sigmund Alfred; Andersen, Lars Bo; Steene-Johannessen, Jostein; Ekelund, Ulf & Hansen, Bjørge Hermann [Show all 7 contributors for this article] (2018). Cross-sectional and prospective associations between sleep, screen time, active school travel, sports/exercise participation and physical activity in children and adolescents. BMC Public Health. 18(1). doi: 10.1186/s12889-018-5610-7. Full text in Research Archive Show summary

  Background: The aim of this study was to investigate how sleep, screen time, active school travel and sport and/or exercise participation associates with moderate-to-vigorous physical activity (MVPA) in nationally representative samples of Norwegian 9- and 15-y-olds, and whether these four behaviors at age nine predict change in MVPA from age nine to 15 years. Method: We pooled cross-sectional accelerometer and questionnaire data from 9- (n = 2366) and 15-y-olds (n = 1554) that participated in the first (2005/06) and second (2011/12) wave of the Physical Activity among Norwegian Children Study to investigate cross-sectional associations. To investigate prospective associations, we used data from a sub-sample that participated in both waves (at age nine and 15 years, n = 517). Results: Cross-sectional analyses indicated a modest, inverse association between screen time and MVPA among 9- (− 2.2 min/d (95% CI: -3.1, − 1.3)) and 15-y-olds (− 1.7 min/d (95% CI: -2.7, − 0.8)). Compared to their peers with 0–5 min/d of active travel to school, 9- and 15-y-olds with ≥16 min/d accumulated 7.2 (95% CI: 4.0, 10.4) and 9.0 (95% CI: 3.8, 14.1) more min/d of MVPA, respectively. Nine-y-old boys and 15-y-olds reporting ≥8 h/week of sports and/or exercise participation accumulated 14.7 (95% CI: 8.2, 21.3) and 17.9 (95% CI: 14.0, 21.8) more min/d of MVPA, respectively, than those reporting ≤2 h/week. We found no cross-sectional association between sleep duration and MVPA in either age group. None of the four behaviors predicted change in MVPA from age nine to 15 years (p ≥ 0.102). Conclusion: Active travel to school and sport/exercise participation may be important targets for future interventions aimed at increasing MVPA in children and adolescents. However, future studies are needed to determine causality.

• Santos, Diana A.; Marques, Adilson; Minderico, Cláudia S.; Ekelund, Ulf & Sardinha, Luís B. (2018). A cross-sectional and prospective analyse of reallocating sedentary time to physical activity on children’s cardiorespiratory fitness. Journal of Sports Sciences. ISSN 0264-0414. 36(15), p. 1720–1726. doi: 10.1080/02640414.2017.1411176. Full text in Research Archive Show summary

  Cardiorespiratory fitness (CRF) is associated with health benefits in children, improving cardiac morphology, cardiovascular disease risk factors, and biological outcomes. This study aimed to examine the substitution effects of displaying a fixed duration of sedentary time with a fixed duration of physical activity (PA) at different intensities on children’s CRF. A total of 315 children (136 boys) were assessed (age: 10.6 ± 0.6 years old). Outcomes at baseline and follow-up (16-months) were CRF determined using a maximal cycle test and sedentary time and PA measured with accelerometers. Data were analysed by isotemporal substitution analyses estimating the effect of reallocating 30 min/day of sedentary time by light (LPA), moderate (MPA) and vigorous physical activity (VPA) on CRF. VPA was positively and significantly associated with CRF cross-sectional (β = 0.026, p < 0.001) and prospectively (β = 0.010, p < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, p < 0.001) and prospectively (β = 0.303, p < 0.05) associated with CRF. Conversely, relocating 30-minutes of sedentary time into 30 minutes of LPA and MPA was not associated with CRF. These results suggest that reallocating an equal amount of time from sedentary into VPA is cross-sectional and prospectively associated with a favourable CRF.

• Mielke, Gregore I.; Brown, Wendy J.; Ekelund, Ulf; Brage, Søren; Goncalves, Helen & Wehrmeister, Fernando César [Show all 8 contributors for this article] (2018). Socioeconomic position and sedentary behavior in Brazilian adolescents: A life-course approach. Preventive Medicine. ISSN 0091-7435. 107, p. 29–35. doi: 10.1016/j.ypmed.2017.12.008. Full text in Research Archive Show summary

  Socioeconomic position (SEP) is a potential correlate of sedentary behavior in adolescents. The aim of this study was to examine the associations between SEP and self-reported and objective measures of sedentary behavior in adolescents, using a life-course approach. Data from the 1993 Pelotas (Brazil) Birth Cohort Study were analyzed (N = 5249). Cross-sectional and longitudinal associations between multiple SEP indicators (maternal education, family income, SEP composite, cumulative family income) at birth, 11, 15 and 18 years, and five sedentary behavior outcomes (≥ 4 h/day screen time; ≥ 4 h/day TV; ≥ 2 h/day computer; ≥ 2 h/day video game; ≥ 12.7 h/day objectively measured sedentary time) at 11, 15 and 18 years, were examined. In cross-sectional analyses, higher SEP was positively associated with more screen time at ages 11 and 15 years. There was a consistent and positive association between higher SEP with time spent using a computer, and with sedentary time assessed through accelerometry. SEP at birth had a positive and direct effect on screen, computer and total sedentary time at 18 years. Participants in the highest cumulative income group had higher odds of high sedentary behavior in screen (OR: 2.40; 95% CI: 1.50–3.54), computer (OR: 7.35; 95% CI: 4.19–12.89) and total sedentary time (OR: 5.40; 95% CI: 3.53–10.35), respectively, compared with their counterparts with lower cumulative income. Our findings showed that SEP is an early determinant of sedentary behavior in adolescents.

• Ekelund, Ulf (2018). Infographic: Physical activity, sitting time and mortality. British Journal of Sports Medicine. ISSN 0306-3674. 52, p. 1164–1165. doi: 10.1136/bjsports-2017-098975. Full text in Research Archive
• Aadland, Eivind; Andersen, Lars Bo; Ekelund, Ulf; Anderssen, Sigmund Alfred & Resaland, Geir Kåre (2018). Reproducibility of domain-specific physical activity over two seasons in children. BMC Public Health. 18(821). doi: 10.1186/s12889-018-5743-8. Full text in Research Archive Show summary

  Background: Knowledge of the reproducibility of domain-specific accelerometer-determined physical activity (PA) estimates are a prerequisite to conduct high-quality epidemiological studies. The aim of this study was to determine the reproducibility of objectively measured PA level in children during school hours, afternoon hours, weekdays, weekend days, and total leisure time over two different seasons. Methods: Six hundred seventy six children from the Active Smarter Kids study conducted in Sogn og Fjordane, Norway, were monitored for 7 days by accelerometry (ActiGraph GT3X+) during January–February and April–May 2015. Reproducibility was estimated week-by-week using intra-class correlation (ICC) and Bland-Altman plots with 95% limits of agreement (LoA). Results: When controlling for season, reliability (ICC) was 0.51–0.66 for a 7-day week, 0.55–0.64 for weekdays, 0.11–0.43 for weekend days, 0.57–0.63 for school hours, 0.42–0.53 for afternoon hours, and 0.42–0.61 for total leisure time. LoA across models approximated a factor of 1.3–2.5 standard deviations of the sample PA levels. 3–6 weeks of monitoring were required to achieve a reliability of 0.80 across all domains but weekend days, which required 5–32 weeks. Conclusion: Reproducibility of PA during leisure time and weekend days were lower than for school hours and weekdays, and estimates were lower when analyzed using a week-by-week approach over different seasons compared to previous studies relying on a single short monitoring period. To avoid type 2-errors, researchers should consider increasing the monitoring period beyond a single 7-day period in future studies.

• Tarp, Jakob; Child, Abbey; White, Tom; Westgate, Kate; Bugge, Anna & Grøntved, Anders [Show all 21 contributors for this article] (2018). Physical activity intensity, bout-duration, and cardiometabolic risk markers in children and adolescents. International Journal of Obesity. ISSN 0307-0565. 42(9), p. 1639–1650. doi: 10.1038/s41366-018-0152-8. Full text in Research Archive Show summary

  Objectives: To determine the role of physical activity intensity and bout-duration in modulating associations between physical activity and cardiometabolic risk markers. Methods: A cross-sectional study using the International Children’s Accelerometry Database (ICAD) including 38,306 observations (in 29,734 individuals aged 4–18 years). Accelerometry data was summarized as time accumulated in 16 combinations of intensity thresholds (≥500 to ≥3000 counts/min) and bout-durations (≥1 to ≥10 min). Outcomes were body mass index (BMI, kg/m2 ), waist circumference, biochemical markers, blood pressure, and a composite score of these metabolic markers. A second composite score excluded the adiposity component. Linear mixed models were applied to elucidate the associations and expressed per 10 min difference in daily activity above the intensity/bout-duration combination. Estimates (and variance) from each of the 16 combinations of intensity and bout-duration examined in the linear mixed models were analyzed in meta-regression to investigate trends in the association. Results: Each 10 min positive difference in physical activity was significantly and inversely associated with the risk factors irrespective of the combination of intensity and bout-duration. In meta-regression, each 1000 counts/min increase in intensity threshold was associated with a −0.027 (95% CI: −0.039 to −0.014) standard deviations lower composite risk score, and a −0.064 (95% CI: −0.09 to −0.038) kg/m2 lower BMI. Conversely, meta-regression suggested bout-duration was not significantly associated with effect-sizes (per 1 min increase in bout-duration: −0.002 (95% CI: −0.005 to 0.0005) standard deviations for the composite risk score, and −0.005 (95% CI: −0.012 to 0.002) kg/m2 for BMI). Conclusions: Time spent at higher intensity physical activity was the main determinant of variation in cardiometabolic risk factors, not bout-duration. Greater magnitude of associations was consistently observed with higher intensities. These results suggest that, in children and adolescents, physical activity, preferably at higher intensities, of any bout-duration should be promoted.

• Hansen, Bjørge Hermann; Kolle, Elin; Steene-Johannessen, Jostein; Dalene, Knut Eirik; Ekelund, Ulf & Anderssen, Sigmund Alfred (2018). Monitoring population levels of physical activity and sedentary time in Norway across the lifespan. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. doi: 10.1111/sms.13314. Full text in Research Archive Show summary

  Purpose: The pandemic of physical inactivity is recognized globally but there is a scarcity of studies employing valid and reliable assessment methods of physical activity (PA) across the lifespan. The purpose of this study is to provide a comprehensive description of objectively measured PA, sedentary time, and prevalence of meeting PA recommendations, in a population‐based sample of Norwegian children, adolescents and adults. Methods: Children and adolescents (6, 9 and 15‐year‐olds) were surveyed in 2011, and adults and older people (20‐85‐year‐olds) were surveyed in 2014/15, including more than 8000 individuals. Anthropometric data were measured in children and adolescents and self‐reported in the adult sample. PA was assessed by ActiGraph accelerometers for seven consecutive days, and PA indices include total PA (counts per minute), intensity‐specific PA, and adherence to PA recommendations. Results: Six‐year‐olds are 21% and 70% more active than 9‐ and 15‐year‐olds, respectively (P < 0.001). Nine‐year‐olds are 40% more active compared to 15‐year‐olds (P < 0.001). Moving from adolescence (15‐year‐olds) into adulthood (20‐65 years) yields a further reduction in total PA by 18%. Among six‐, nine‐ and 15‐year olds, 90%, 77%, and 48% meet the current PA recommendations, respectively, while adherence among adults and older people are 33% and 31%, respectively. Overweight and obese individuals had lower odds of meeting PA recommendations. Conclusions: The results from the Norwegian surveillance system indicate a strong association between age and indices of physical activity. The vast majority of Norwegian adults do not meet the PA recommendations and public health action are needed to increase PA in Norway.

• Renninger, Marius; Løchen, Maja-Lisa; Ekelund, Ulf; Hopstock, Laila Arnesdatter; Jørgensen, Lone & Mathiesen, Ellisiv B. [Show all 10 contributors for this article] (2018). The independent and joint associations of physical activity and body mass index with myocardial infarction: The Tromsø Study. Preventive Medicine. ISSN 0091-7435. 116, p. 94–98. doi: 10.1016/j.ypmed.2018.09.005. Full text in Research Archive Show summary

  Physical activity and overweight are associated with myocardial infarction (MI). However, their joint association with MI remains unclear. Our objective was to examine the independent and joint association between leisuretime physical activity (LTPA), body mass index (BMI) and MI. This prospective cohort study included 16,572 men and women (47.5% women) aged 20–54 years who took part in the second Tromsø Study. At baseline in 1979–80 LTPA was assessed by questionnaire. Data on MI was collected and adjudicated through hospital and causes of death registries between 1979 and 2013. Cox proportional hazards models were used to examine the independent and joint associations between LTPA, BMI and MI. The final sample included 16,104 individuals. During a median follow up of 34 years, 1613 incident cases of MI were recorded. Physical inactivity and elevated BMI were both independently associated with MI (p for trend 0.02 and < 0.001). In joint analyses, normal weight, inactive individuals had a 20% higher risk of MI compared to their active counterparts (hazard ratio (HR) 1.20 (1.02–1.41)). The highest risk of MI was seen in obese, inactive individuals when compared to normal weight, active individuals (HR 3.20 (2.30–4.44)). The risk of MI increased with increasing BMI regardless of the activity level. HRs were lower for active compared to inactive individuals within the same BMI category. The findings suggest that LTPA and BMI are independently associated with risk of MI. LTPA seems to attenuate but not eliminate the risk of MI associated with excess bodyweight.

• Schaan, Camila W.; Cureau, Felipe Vogt; Bloch, Katia Vergetti; Carvalho, Kênia Mara Baiocchi de; Ekelund, Ulf & Schaan, Beatriz D. (2018). Prevalence and correlates of screen time among Brazilian adolescents: findings from a country-wide survey. Applied Physiology, Nutrition and Metabolism. ISSN 1715-5312. 43(7), p. 684–690. doi: 10.1139/apnm-2017-0630. Full text in Research Archive Show summary

  Background: To evaluate the distribution, prevalence and correlates of excessive screen time (>2 hours/day) among Brazilian adolescents. Methods: The Study of Cardiovascular Risks in Adolescents (ERICA) is a national, school-based, cross-sectional multicenter study. Information about time spent in front of screens was assessed by questionnaire. Poisson regression models were used to examine the associations between following correlates (region, sex, age, skin color, income, internet access and number of TVs at home) and excessive screen time. Results: A total of 66,706 Brazilian adolescents (12-17 years) were included. The overall mean time in front of screens was 3.25 h/day (95% CI: 3.20-3.31) and the prevalence of excessive screen time was 57.3% (95%CI: 55.9-58.6). Moreover, excessive screen time also differ across Brazilian regions, being higher in Southeast and South, respectively. In adjusted models stratified by region, the socioeconomic status was associated with excessive screen time in North, Northeast and Midwest. In all regions, having a computer with internet access was associated with higher prevalence of excessive screen time. Conclusions: The prevalence of excessive screen time in Brazilian adolescents is high. It presents regional variations and facility for access the internet.

• Anokye, Nana; Fox-Rushby, Julia; Sanghera, Sabina; Cook, Derek G.; Limb, Elizabeth & Furness, Cheryl [Show all 14 contributors for this article] (2018). Short-term and long-term cost-effectiveness of a pedometer-based exercise intervention in primary care: a within-trial analysis and beyond-trial modelling. BMJ Open. 8(10). doi: 10.1136/bmjopen-2018-021978. Full text in Research Archive Show summary

  Objectives: A short-term and long-term cost-effectiveness analysis (CEA) of two pedometer-based walking interventions compared with usual care. Design: (A) Short-term CEA: parallel three-arm cluster randomised trial randomised by household. (B) Long-term CEA: Markov decision model. Setting: Seven primary care practices in South London, UK. Participants: (A) Short-term CEA: 1023 people (922 households) aged 45–75 years without physical activity (PA) contraindications. (b) Long-term CEA: a cohort of 100 000 people aged 59–88 years. Interventions: Pedometers, 12-week walking programmes and PA diaries delivered by post or through three PA consultations with practice nurses. Primary and secondary outcome measures: Accelerometer-measured change (baseline to 12 months) in average daily step count and time in 10 min bouts of moderate to vigorous PA (MVPA), and EQ-5D-5L quality-adjusted life-years (QALY). Methods: Resource use costs (£2013/2014) from a National Health Service perspective, presented as incremental cost-effectiveness ratios for each outcome over a 1-year and lifetime horizon, with cost-effectiveness acceptability curves and willingness to pay per QALY. Deterministic and probabilistic sensitivity analyses evaluate uncertainty. Results: (A) Short-term CEA: At 12 months, incremental cost was £3.61 (£109)/min in ≥10 min MVPA bouts for nurse support compared with control (postal group). At £20 000/QALY, the postal group had a 50% chance of being cost saving compared with control. (B) Long-term CEA: The postal group had more QALYs (+759 QALYs, 95% CI 400 to 1247) and lower costs (−£11 million, 95% CI −12 to −10) than control and nurse groups, resulting in an incremental net monetary benefit of £26 million per 100 000 population. Results were sensitive to reporting serious adverse events, excluding health service use, and including all participant costs. Conclusions: Postal delivery of a pedometer intervention in primary care is cost-effective long term and has a 50% chance of being cost-effective, through resource savings, within 1 year. Further research should ascertain maintenance of the higher levels of PA, and its impact on quality of life and health service use.

• Ekelund, Ulf; Brown, Wendy J; Steene-Johannessen, Jostein; Fagerland, Morten; Owen, Neville & Powell, Kenneth E. [Show all 8 contributors for this article] (2018). Do the associations of sedentary behaviour with cardiovascular disease mortality and cancer mortality differ by physical activity level? A systematic review and harmonised meta-analysis of data from 850 060 participants. British Journal of Sports Medicine. ISSN 0306-3674. 53(14), p. 886–894. doi: 10.1136/bjsports-2017-098963. Full text in Research Archive Show summary

  Objective: To examine whether the associations between sedentary behaviours (ie, daily sitting/TV-viewing time) and mortality from cardiovascular disease (CVD) and cancer differ by different levels of physical activity (PA). Design: Harmonised meta-analysis of prospective cohort studies. Data on exposure variables were harmonised according to a predefined protocol and categorised into four groups for sedentary behaviours and into quartiles of PA (MET-hour/week). Data sources: PubMed, PsycINFO, Embase, Web of Science, Sport Discus and Scopus. Eligibility criteria for selecting studies: Individual level data on both sedentary behaviours and PA and reported effect estimates for CVD or cancer mortality. Results: Nine studies (n=850 060; deaths=25 730) and eight studies (n=777 696; deaths=30 851) provided data on sitting time and CVD and cancer mortality, respectively. Five studies had data on TV-viewing time and CVD (n=458 127; deaths=13 230) and cancer (n=458 091; deaths=16 430) mortality. A dose–response association between sitting time (9%–32% higher risk; p for trend <0.001) and TV time (3%–59% higher risk; p for trend <0.001) with CVD mortality was observed in the ‘inactive’, lowest quartile of PA. Associations were less consistent in the second and third quartiles of PA, and there was no increased risk for CVD mortality with increasing sedentary behaviours in the most active quartile. Associations between sedentary behaviours and cancer mortality were generally weaker; 6%–21% higher risk with longer sitting time observed only in the lowest quartile of PA. Conclusion: PA modifies the associations between sedentary behaviours and CVD and cancer mortality. These findings emphasise the importance of higher volumes of moderate and vigorous activity to reduce, or even eliminate these risks, especially for those who sit a lot in their daily lives.

• Zhou, Bin; Bentham, James; Cesare, Mariachiara Di; Bixby, Honor; Danaei, Goodarz & Hajifathalian, Kaveh [Show all 847 contributors for this article] (2018). Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants. International Journal of Epidemiology. ISSN 0300-5771. 47(3), p. 872–883i. doi: 10.1093/ije/dyy016. Full text in Research Archive Show summary

  Background Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20–29 years to 70–79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results In 2005–16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

• Stavnsbo, Mette; Resaland, Geir Kåre; Anderssen, Sigmund Alfred; Steene-Johannessen, Jostein; Domazet, Sidsel Louise & Skrede, Turid [Show all 11 contributors for this article] (2018). Reference values for cardiometabolic risk scores in children and adolescents: Suggesting a common standard. Atherosclerosis. ISSN 0021-9150. 278, p. 299–306. doi: 10.1016/j.atherosclerosis.2018.10.003. Full text in Research Archive Show summary

  Background and aims: International reference values for cardiometabolic risk variables, to allow for standardization of continuous risk scores in children, are not currently available. The aim of this study was to provide international age- and gender-specific reference values for cardiometabolic risk factors in children and adolescents. Methods: Cohorts of children sampled from different parts of Europe (North, South, Mid and Eastern) and from the United States were pooled. In total, 22,479 observations (48.7% European vs. 51.3% American), 11,234 from girls and 11,245 from boys, aged 6–18 years were included in the study. Linear mixed-model regression analysis was used to analyze the associations between age and each cardiometabolic risk factor. Results: Reference values for 14 of the most commonly used cardiometabolic risk variables in clustered risk scores were calculated and presented by age and gender: systolic blood pressure (SBP), diastolic blood pressure (DBP), waist circumference (WC), body mass index (BMI), sum of 4 skinfolds (sum4skin), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), TC:HDL-C ratio, glucose, insulin, homeostatic model assessment-score (HOMA-score), and cardiorespiratory fitness (CRF). Conclusions: This study suggests a common standard to define cardiometabolic risk in children. Adapting this approach makes single risk factors and clustered cardiometabolic disease risk scores comparable to the reference material itself and comparable to cardiometabolic risk values in studies using the same strategy. This unified approach therefore increases the prospect to estimate and compare prevalence and trends of cardiometabolic risk in children when using continuous cardiometabolic risk scores.

• Furness, Cheryl; Howard, Emma; Limb, Elizabeth; Cook, Derek G.; Kerry, Sally & Wahlich, Charlotte [Show all 15 contributors for this article] (2018). Relating process evaluation measures to complex intervention outcomes: findings from the PACE-UP primary care pedometer-based walking trial. Trials. 19(1). doi: 10.1186/s13063-017-2428-z. Full text in Research Archive Show summary

  Background: The PACE-UP trial demonstrated positive effects of a pedometer-based walking intervention on objective physical activity (PA) outcomes at three and 12 months in 45–75-year-old primary care patients, in postal and nurse-supported trial arms compared with controls. We explored associations between process evaluation measures and change in PA outcomes. Methods: The MRC framework guided process evaluation. Three quantitative measures (nurse session attendance [dose delivered], PA diary completion [fidelity] and pedometer use [fidelity]) were selected as independent variables in multi-level models estimating intervention effectiveness on PA outcomes (changes in step-counts and time in moderate-to-vigorous PA [MVPA] levels in ≥ 10-min bouts). Results: Dose: attending all three nurse sessions compared with 0–2 sessions was associated with an increase in steps/day at three and 12 months of 1197 (95% confidence interval [CI] = 627–1766) and 605 (95% CI = 74–1137), respectively; and MVPA in bouts (min/week) at three and 12 months by 74 (95% CI = 45–103) and 30 (95% CI = 3–57), respectively. Fidelity: postal and nurse groups showed strong positive associations of diary return with steps/day at three months: postal 1458 (95% CI = 854–2061), nurse 873 (95% CI = 190–1555). MVPA in bouts (min/week): postal 64 (95% CI = 33–94), nurse 50 (95% CI = 15–85). At 12 months, only the postal group effects remained statistically significant: steps/day 1114 (95% CI = 538–1689), MVPA 47 (95% CI = 18–75). Regular pedometer use in the postal group only was associated with higher three-month and 12-month steps/day: 1029 (95% CI = 383–1675) and 606 (95% CI = 22–1190), respectively, and with MVPA in bouts at three months: 40 (95% CI = 6–73). Conclusion: Process evaluation measures demonstrated significant associations with PA outcomes at three and 12 months. We cannot infer causality, but the associations between the process measures and PA outcomes suggest that they were important in enabling the trial changes observed and should be considered core components of the PACE-UP nurse and postal interventions. We have shown the MRC framework to be a useful tool for process evaluation of intervention implementation.

• Anderssen, Sigmund Alfred & Ekelund, Ulf (2018). Anbefalinger for fysisk aktivitet. In Torstveit, Monica Klungland; Lohne-Seiler, Hilde; Berntsen, Sveinung & Anderssen, Sigmund Alfred (Ed.), Fysisk aktivitet og helse: Fra begrepsforståelse til implementering av kunnskap. Cappelen Damm Akademisk. ISSN 9788202568313. p. 55–61. Full text in Research Archive
• Dowd, Kieran P.; Szeklicki, Robert; Minetto, Marco Alessandro; Murphy, Marie; Polito, Angela & Ghigo, Ezio [Show all 12 contributors for this article] (2018). A systematic literature review of reviews on techniques for physical activity measurement in adults: a DEDIPAC study. International Journal of Behavioral Nutrition and Physical Activity. 15(1). doi: 10.1186/s12966-017-0636-2. Full text in Research Archive Show summary

  The links between increased participation in Physical Activity (PA) and improvements in health are well established. As this body of evidence has grown, so too has the search for measures of PA with high levels of methodological effectiveness (i.e. validity, reliability and responsiveness to change). The aim of this “review of reviews” was to provide a comprehensive overview of the methodological effectiveness of currently employed measures of PA, to aid researchers in their selection of an appropriate tool. A total of 63 review articles were included in this review, and the original articles cited by these reviews were included in order to extract detailed information on methodological effectiveness. Self-report measures of PA have been most frequently examined for methodological effectiveness, with highly variable findings identified across a broad range of behaviours. The evidence-base for the methodological effectiveness of objective monitors, particularly accelerometers/activity monitors, is increasing, with lower levels of variability observed for validity and reliability when compared to subjective measures. Unfortunately, responsiveness to change across all measures and behaviours remains under-researched, with limited information available. Other criteria beyond methodological effectiveness often influence tool selection, including cost and feasibility. However, researchers must be aware of the methodological effectiveness of any measure selected for use when examining PA. Although no “perfect” tool for the examination of PA in adults exists, it is suggested that researchers aim to incorporate appropriate objective measures, specific to the behaviours of interests, when examining PA in free-living environments.

• Adab, Peymane; Pallan, Miranda J.; Lancashire, Emma R.; Hemming, Karla; Frew, Emma & Barrett, Tim [Show all 22 contributors for this article] (2018). Effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6 and 7 year olds: cluster randomised controlled trial (WAVES study). The BMJ. 360. doi: 10.1136/bmj.k211. Full text in Research Archive Show summary

  Abstract: Objective To assess the effectiveness of a school and family based healthy lifestyle programme (WAVES intervention) compared with usual practice, in preventing childhood obesity. Design: Cluster randomised controlled trial. Setting: UK primary schools from the West Midlands. Participants: 200 schools were randomly selected from all state run primary schools within 35 miles of the study centre (n=980), oversampling those with high minority ethnic populations. These schools were randomly ordered and sequentially invited to participate. 144 eligible schools were approached to achieve the target recruitment of 54 schools. After baseline measurements 1467 year 1 pupils aged 5 and 6 years (control: 28 schools, 778 pupils) were randomised, using a blocked balancing algorithm. 53 schools remained in the trial and data on 1287 (87.7%) and 1169 (79.7%) pupils were available at first follow-up (15 month) and second follow-up (30 month), respectively. Interventions: The 12 month intervention encouraged healthy eating and physical activity, including a daily additional 30 minute school time physical activity opportunity, a six week interactive skill based programme in conjunction with Aston Villa football club, signposting of local family physical activity opportunities through mail-outs every six months, and termly school led family workshops on healthy cooking skills. Main outcome measures: The protocol defined primary outcomes, assessed blind to allocation, were between arm difference in body mass index (BMI) z score at 15 and 30 months. Secondary outcomes were further anthropometric, dietary, physical activity, and psychological measurements, and difference in BMI z score at 39 months in a subset. Results: Data for primary outcome analyses were: baseline, 54 schools: 1392 pupils (732 controls); first follow-up (15 months post-baseline), 53 schools: 1249 pupils (675 controls); second follow-up (30 months post-baseline), 53 schools: 1145 pupils (621 controls). The mean BMI z score was non-significantly lower in the intervention arm compared with the control arm at 15 months (mean difference −0.075 (95% confidence interval −0.183 to 0.033, P=0.18) in the baseline adjusted models. At 30 months the mean difference was −0.027 (−0.137 to 0.083, P=0.63). There was no statistically significant difference between groups for other anthropometric, dietary, physical activity, or psychological measurements (including assessment of harm). Conclusions: The primary analyses suggest that this experiential focused intervention had no statistically significant effect on BMI z score or on preventing childhood obesity. Schools are unlikely to impact on the childhood obesity epidemic by incorporating such interventions without wider support across multiple sectors and environments.

• Nightingale, Claire M.; Rudnicka, Alicja R; Kerry-Barnard, Sarah R.; Donin, Angela S.; Brage, Søren & Westgate, Kate L. [Show all 10 contributors for this article] (2018). The contribution of physical fitness to individual and ethnic differences in risk markers for type 2 diabetes in children: The Child Heart and Health Study in England (CHASE). Pediatric Diabetes. ISSN 1399-543X. 19(4), p. 603–610. doi: 10.1111/pedi.12637. Full text in Research Archive Show summary

  Background: The relationship between physical fitness and risk markers for type 2 diabetes (T2D) in children and the contribution to ethnic differences in these risk markers have been little studied. We examined associations between physical fitness and early risk markers for T2D and cardiovascular disease in 9‐ to 10‐year‐old UK children. Methods: Cross‐sectional study of 1445 9‐ to 10‐year‐old UK children of South Asian, black African‐Caribbean and white European origin. A fasting blood sample was used for measurement of insulin, glucose (from which homeostasis model assessment [HOMA]‐insulin resistance [IR] was derived), glycated hemoglobin (HbA1c), urate, C‐reactive protein (CRP), and lipids. Measurements of blood pressure (BP) and fat mass index (FMI) were made; physical activity was measured by accelerometry. Estimated VO2 max was derived from a submaximal fitness step test. Associations were estimated using multilevel linear regression. Results: Higher VO2 max was associated with lower FMI, insulin, HOMA‐IR, HbA1c, glucose, urate, CRP, triglycerides, LDL‐cholesterol, BP and higher HDL‐cholesterol. Associations were reduced by adjustment for FMI, but those for insulin, HOMA‐IR, glucose, urate, CRP, triglycerides and BP remained statistically significant. Higher levels of insulin and HOMA‐IR in South Asian children were partially explained by lower levels of VO2max compared to white Europeans, accounting for 11% of the difference. Conclusions: Physical fitness is associated with risk markers for T2D and CVD in children, which persist after adjustment for adiposity. Higher levels of IR in South Asians are partially explained by lower physical fitness levels compared to white Europeans. Improving physical fitness may provide scope for reducing risks of T2D.

• Adab, Peymane; Barrett, Timothy; Bhopal, Raj; Cade, Janet E.; Canaway, Alastair & Cheng, Kar Keung [Show all 22 contributors for this article] (2018). The West Midlands ActiVe lifestyle and healthy Eating in School children (WAVES) study: a cluster randomised controlled trial testing the clinical effectiveness and cost-effectiveness of a multifaceted obesity prevention intervention programme targeted at children aged 6-7 years. Health Technology Assessment. ISSN 1366-5278. 22(8), p. 1–644. doi: 10.3310/hta22080. Full text in Research Archive Show summary

  Background: Systematic reviews suggest that school-based interventions can be effective in preventing childhood obesity, but better-designed trials are needed that consider costs, process, equity, potential harms and longer-term outcomes. Objective: To assess the clinical effectiveness and cost-effectiveness of the WAVES (West Midlands ActiVe lifestyle and healthy Eating in School children) study intervention, compared with usual practice, in preventing obesity among primary school children. Design: A cluster randomised controlled trial, split across two groups, which were randomised using a blocked balancing algorithm. Schools/participants could not be blinded to trial arm. Measurement staff were blind to allocation arm as far as possible. Setting: Primary schools, West Midlands, UK. Participants: Schools within a 35-mile radius of the study centre and all year 1 pupils (aged 5–6 years) were eligible. Schools with a higher proportion of pupils from minority ethnic populations were oversampled to enable subgroup analyses. Interventions: The 12-month intervention encouraged healthy eating/physical activity (PA) by (1) helping teachers to provide 30 minutes of additional daily PA, (2) promoting ‘Villa Vitality’ (interactive healthy lifestyles learning, in an inspirational setting), (3) running school-based healthy cooking skills/education workshops for parents and children and (4) highlighting information to families with regard to local PA opportunities. Main outcome measures: The primary outcomes were the difference in body mass index z-scores (BMI-zs) between arms (adjusted for baseline body mass index) at 3 and 18 months post intervention (clinical outcome), and cost per quality-adjusted life-year (QALY) (cost-effectiveness outcome). The secondary outcomes were further anthropometric, dietary, PA and psychological measurements, and the difference in BMI-z between arms at 27 months post intervention in a subset of schools. Results: Two groups of schools were randomised: 27 in 2011 (n = 650 pupils) [group 1 (G1)] and another 27 in 2012 (n = 817 pupils) [group 2 (G2)]. Primary outcome data were available at first follow-up (n = 1249 pupils) and second follow-up (n = 1145 pupils) from 53 schools. The mean difference (MD) in BMI-z between the control and intervention arms was –0.075 [95% confidence interval (CI) –0.183 to 0.033] and –0.027 (95% CI –0.137 to 0.083) at 3 and 18 months post intervention, respectively. The main analyses showed no evidence of between-arm differences for any secondary outcomes. Third follow-up included data on 467 pupils from 27 G1 schools, and showed a statistically significant difference in BMI-z (MD –0.20, 95% CI –0.40 to –0.01). The mean cost of the intervention was £266.35 per consented child (£155.53 per child receiving the intervention). The incremental cost-effectiveness ratio associated with the base case was £46,083 per QALY (best case £26,804 per QALY), suggesting that the intervention was not cost-effective. Limitations: The presence of baseline primary outcome imbalance between the arms, and interschool variation in fidelity of intervention delivery. Conclusions: The primary analyses show no evidence of clinical effectiveness or cost-effectiveness of the WAVES study intervention. A post hoc analysis, driven by findings at third follow-up, suggests a possible intervention effect, which could have been attenuated by baseline imbalances. There was no evidence of an intervention effect on measures of diet or PA and no evidence of harm. Future work: A realist evidence synthesis could provide insights into contextual factors and strategies for future interventions. School-based interventions need to be integrated within a wider societal framework and supported by upstream interventions.

• Skrede, Turid; Aadland, Eivind; Andersen, Lars Bo; Stavnsbo, Mette; Anderssen, Sigmund Alfred & Resaland, Geir Kåre [Show all 7 contributors for this article] (2018). Does cardiorespiratory fitness moderate the prospective association between physical activity and cardiometabolic risk factors in children? International Journal of Obesity. ISSN 0307-0565. 42, p. 1029–1038. doi: 10.1038/s41366-018-0108-z. Full text in Research Archive Show summary

  Background/Objectives: Physical activity (PA) and cardiorespiratory fitness (CRF) are independently associated with reduced cardiometabolic risk in children, and may affect risk through different pathways. This study aims to examine if CRF moderate the prospective association between PA, sedentary time, and cardiometabolic outcomes in 10-year-old children. Subjects/Methods: In total, 718 children of 1129 (drop out n = 7) had valid measures of PA (accelerometry), CRF (the Andersen running test), and a cardiometabolic risk profile measured at baseline and follow-up 7 months later. Cardiometabolic outcomes were systolic blood pressure, waist circumference (WC), total cholesterol, high-density lipoprotein, triglycerides, glucose, and insulin (HOMA-IR). The cardiometabolic risk factors were analysed individually, and as a clustered risk score (z score). A linear mixed model was used to examine the prospective associations between different PA exposures (overall PA, sedentary time, moderate-to-vigorous PA (MVPA), vigorous PA) and cardiometabolic outcomes, including the interaction term PA × CRF in the model to assess moderation by CRF. Results: CRF modified the association for baseline overall PA (P < 0.039) and MVPA (min/day) with clustered cardiometabolic risk at follow-up (P < 0.023). Moreover, CRF modified the association between overall PA and MVPA with HOMA-IR independent of WC (P < 0.022). When stratified by CRF level (median split; high/low), MVPA predicted lower HOMA-IR [MVPA β −0.133 (95% CI: −0.223, −0.043); P = 0.004] and clustered cardiometabolic risk [MVPA β −0.094 (95% CI: −0.169, −0.019); P = 0.014] in children with low CRF, but not among their fitter peers (P > 0.232). There was neither direct association between sedentary time and cardiometabolic risk factors in any analyses, nor moderation by CRF. Conclusion: CRF significantly moderated the prospective association between PA and the clustered cardiometabolic risk, but not for time spent sedentary. The magnitude of association between MVPA and clustered cardiometabolic risk was stronger in children with low CRF, and no associations appeared present in their high-fit peers.

• Skrede, Turid; Steene-Johannessen, Jostein; Anderssen, Sigmund Alfred; Resaland, Geir Kåre & Ekelund, Ulf (2018). The prospective association between objectively measured sedentary time, moderate-to-vigorous physical activity and cardiometabolic risk factors in youth: a systematic review and meta-analysis. Obesity Reviews. ISSN 1467-7881. p. 1–20. doi: 10.1111/obr.12758. Full text in Research Archive Show summary

  Sedentary time and moderate‐to‐vigorous physical activity (MVPA) may be uniquely related to cardiometabolic health. Excessive sedentary time is suggested as an independent cardiometabolic risk factor, while MVPA is favourably associated with cardiometabolic health. This systematic review and meta‐analysis summarizes the evidence on a prospective relationship between objectively measured sedentary time, MVPA and cardiometabolic health indicators in youth. PubMed, Embase, CINAHL, PhyscINFO and SPORTDiscus were systematically searched from January 2000 until April 2018. Studies were included if sedentary time and physical activity were measured objectively and examined associations with body mass index, waist circumference, triglycerides, high‐density lipoprotein, insulin, blood pressure or the clustering of these cardiometabolic risk factors. We identified 30 studies, of which 21 were of high quality. No evidence was found for an association between sedentary time and cardiometabolic outcomes. The association between MVPA and individual cardiometabolic risk factors was inconsistent. The meta‐analysis for prospective studies found a small but significant effect size between MVPA at baseline and clustered cardiometabolic risk at follow‐up (ES –0.014 [95% CI, −0.024 to −0.004]). We conclude that there is no prospective association between sedentary time and cardiometabolic health, while MVPA is beneficially associated with cardiometabolic health in youth.

• Harris, Tess; Kerry, Sally; Victor, Christina; Iliffe, Steve; Ussher, Michael & Fox-Rushby, Julia [Show all 23 contributors for this article] (2018). A pedometer-based walking intervention in 45- to 75-year-olds, with and without practice nurse support: The PACE-UP three-arm cluster RCT. Health Technology Assessment. ISSN 1366-5278. 22(37), p. 1–273. doi: 10.3310/hta22370. Full text in Research Archive
• Zhou, Bin; Bentham, James; Cesare, Mariachiara Di; Bixby, Honor; Danaei, Goodarz & Cowan, Melanie J. [Show all 114 contributors for this article] (2017). Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19·1 million participants. The Lancet. ISSN 0140-6736. 389(10064), p. 37–55. doi: 10.1016/S0140-6736(16)31919-5. Full text in Research Archive Show summary

  Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher. Methods For this analysis, we pooled national, subnational, or community population-based studies that had measured blood pressure in adults aged 18 years and older. We used a Bayesian hierarchical model to estimate trends from 1975 to 2015 in mean systolic and mean diastolic blood pressure, and the prevalence of raised blood pressure for 200 countries. We calculated the contributions of changes in prevalence versus population growth and ageing to the increase in the number of adults with raised blood pressure. Findings We pooled 1479 studies that had measured the blood pressures of 19·1 million adults. Global age-standardised mean systolic blood pressure in 2015 was 127·0 mm Hg (95% credible interval 125·7–128·3) in men and 122·3 mm Hg (121·0–123·6) in women; age-standardised mean diastolic blood pressure was 78·7 mm Hg (77·9–79·5) for men and 76·7 mm Hg (75·9–77·6) for women. Global age-standardised prevalence of raised blood pressure was 24·1% (21·4–27·1) in men and 20·1% (17·8–22·5) in women in 2015. Mean systolic and mean diastolic blood pressure decreased substantially from 1975 to 2015 in high-income western and Asia Pacific countries, moving these countries from having some of the highest worldwide blood pressure in 1975 to the lowest in 2015. Mean blood pressure also decreased in women in central and eastern Europe, Latin America and the Caribbean, and, more recently, central Asia, Middle East, and north Africa, but the estimated trends in these super-regions had larger uncertainty than in high-income super-regions. By contrast, mean blood pressure might have increased in east and southeast Asia, south Asia, Oceania, and sub-Saharan Africa. In 2015, central and eastern Europe, sub-Saharan Africa, and south Asia had the highest blood pressure levels. Prevalence of raised blood pressure decreased in high-income and some middle-income countries; it remained unchanged elsewhere. The number of adults with raised blood pressure increased from 594 million in 1975 to 1·13 billion in 2015, with the increase largely in low-income and middle-income countries. The global increase in the number of adults with raised blood pressure is a net effect of increase due to population growth and ageing, and decrease due to declining age-specific prevalence. Interpretation During the past four decades, the highest worldwide blood pressure levels have shifted from high-income countries to low-income countries in south Asia and sub-Saharan Africa due to opposite trends, while blood pressure has been persistently high in central and eastern Europe.

• Dugas, Lara R.; Kliethermes, Stephanie; Plange-Rhule, Jacob; Tong, Liping; Bovet, Pascal & Forrester, Terrence E. [Show all 15 contributors for this article] (2017). Accelerometer-measured physical activity is not associated with two-year weight change in African-origin adults from five diverse populations. PeerJ. doi: 10.7717/peerj.2902. Full text in Research Archive Show summary

  Background: Increasing population-levels of physical activity (PA) is a controversial strategy for managing the obesity epidemic, given the conflicting evidence for weight loss from PA alone per se. We measured PA and weight change in a three-year prospective cohort study in young adults from five countries (Ghana, South Africa, Jamaica, Seychelles and USA). Methods: A total of 1,944 men and women had baseline data, and at least 1 follow-up examination including measures of anthropometry (weight/BMI), and objective PA (accelerometer, 7-day) following the three-year study period. PA was explored as 1-minute bouts of moderate and vigorous PA (MVPA) as well as daily sedentary time. Results: At baseline; Ghanaian and South African men had the lowest body weights (63.4 ± 9.5, 64.9 ± 11.8 kg, respectively) and men and women from the USA the highest (93.6 ± 25.9, 91.7 ± 23.4 kg, respectively). Prevalence of normal weight ranged from 85% in Ghanaian men to 29% in USA men and 52% in Ghanaian women to 15% in USA women. Over the two-year follow-up period, USA men and Jamaican women experienced the smallest yearly weight change rate (0.1 ± 3.3 kg/yr; −0.03 ± 3.0 kg/yr, respectively), compared to South African men and Ghanaian women greatest yearly change (0.6.0 ± 3.0 kg/yr; 1.22 ± 2.6 kg/yr, respectively). Mean yearly weight gain tended to be larger among normal weight participants at baseline than overweight/obese at baseline. Neither baseline MVPA nor sedentary time were associated with weight gain. Using multiple linear regression, only baseline weight, age and gender were significantly associated with weight gain. Discussion: From our study it is not evident that higher volumes of PA alone are protective against future weight gain, and by deduction our data suggest that other environmental factors such as the food environment may have a more critical role.

• Cureau, Felipe Vogt; Ekelund, Ulf; Bloch, Katia Vergetti & Schaan, Beatriz D. (2017). Does body mass index modify the association between physical activity and screen time with cardiometabolic risk factors in adolescents? Findings from a country-wide survey. International Journal of Obesity. ISSN 0307-0565. 41(4), p. 551–559. doi: 10.1038/ijo.2016.210. Full text in Research Archive Show summary

  BACKGROUND: Moderate and vigorous physical activity (MVPA) and screen time (ST) have been associated with cardiometabolic health in youth. However, previous studies are conflicting whether these associations are independent of each other and it is unknown if they are modified by adiposity. We aimed to examine the independent and joint associations between MVPA and ST with cardiometabolic risk across body mass index (BMI) categories. METHODS: A total of 36 956 Brazilian adolescents (12-17 years) from the Study of Cardiovascular Risks in Adolescents were included. Information on time spent in MVPA and ST were assessed by self-reports. Blood pressure, Homeostasis Model Assessment of Insulin Resistance, triglycerides, high-density lipoprotein-cholesterol and waist circumference were used to calculate a cardiometabolic risk score (sex-age-specific top-risk quintile for each biomarker). Ordered logistic regression was used to examine the associations. RESULTS: In final adjusted models, both higher MVPA (proportional odds ratio (POR)=0.80; 95% confidence interval (CI): 0.67-0.95) and ST (POR=1.23; 95% CI: 1.10-1.37) were independently associated with cardiometabolic risk. After stratification by normal weight vs overweight/obese, the inverse independent association for MVPA remained unchanged, whereas ST was positively associated with cardiometabolic risk only in overweight/obese adolescents (POR=1.62; 95% CI: 1.18-2.22). Participants who met the recommendations for both MVPA and ST had lower odds for cardiometabolic risk, especially if they were overweight/obese (POR=0.46; 95% CI: 0.31-0.68). CONCLUSIONS: MVPA and ST are independently associated with cardiometabolic risk; the association with ST, however, appears modified by BMI. Normal-weight adolescents should be encouraged to increase MVPA, whereas a combination of increasing MVPA and decreasing ST is recommended in those who are overweight or obese.

• Kolle, Elin; Horta, Bernardo L; Wells, Jonathan; Brage, Soren; Barros, Fernando C. & Ekelund, Ulf [Show all 7 contributors for this article] (2017). Does objectively measured physical activity modify the association between early weight gain and fat mass in young adulthood? BMC Public Health. 17(1). doi: 10.1186/s12889-017-4924-1. Full text in Research Archive Show summary

  Background: Substantial evidence suggests that weight gain in early life is associated with increased adiposity and other metabolic disorders later in life. It is, however, unknown whether physical activity (PA) may modify these associations. We aimed to examine whether objectively measured PA at 30 years modified the associations between conditional weight gain in infancy (0–2 y) and childhood (2–4 y) with fat mass index (FMI) and visceral abdominal fat measured at age 30 years. Methods: Prospective birth cohort study in Pelotas, Brazil, including 1874 participants with weight data at birth, two and four years of age, and measures of FMI, visceral abdominal fat and PA at a mean age of 30.2 years. At age 30, time spent (min/day) in moderate-to-vigorous physical activity (MVPA) was measured objectively using a wrist-worn accelerometer worn for four to seven consecutive days.. Multiple linear regression analyses was performed to assess the associations between conditional weight gain and outcome variables at 30 years, adjusting for covariates. We examined whether PA modified the association between conditional weight gain and the outcomes of interest by introducing an interaction term (conditional weight gain × PA) in the models. Results: Conditional weight gain in infancy and childhood were both positively associated with later FMI (infancy weight gain: β = 0.68, 95% CI: 0.48, 0.88; P < 0.001; childhood weight gain: β = 0.91, 95% CI: 0.70, 1.11; P < 0.001). A formal test for interaction suggested that MVPA at 30 years of age modified the association between childhood relative weight gain and later FMI (β = −0.006, 95% CI: -0.011, −0.001; P = 0.029), suggesting stronger associations between weight gain and FMI in those with lower levels of MVPA. Conditional weight gain in childhood was also positively associated with visceral abdominal fat (β = 0.24, 95% CI: 0.15, 0424, P < 0.001). There was no evidence for a modification of the latter association after adjustment for physical activity. Conclusion: Conditional weight gain between 2 and 4 years of age is associated with increased FMI at age 30 years. However, higher levels of MVPA appear to attenuate this detrimental association.

• Nakamura, Priscila M.; Mielke, Grégory; Horta, Bernardo L.; Assunção, Maria Cecília; Gonçalves, Helen D. & Menezes, Ana M.B. [Show all 12 contributors for this article] (2017). Physical Activity Throughout Adolescence and Hba1c in Early Adulthood: Birth Cohort Study. Journal of Physical Activity and Health. ISSN 1543-3080. 14(5), p. 375–381. doi: 10.1123/jpah.2016-0245. Full text in Research Archive Show summary

  Background: Physical inactivity is responsible for 7% of diabetes deaths worldwide, but little is known whether low levels of physical activity (PA) during adolescence increase the risk of diabetes in early adulthood. We evaluated the cross-sectional and longitudinal associations between PA throughout adolescence and HbA1c concentration in early adulthood. Methods: HbA1c was measured by high performance liquid chromatography. PA was assessed by self-report at the ages of 11, 15, and 18 years and by accelerometry at the ages of 13 (subsample) and 18 years. The loss percentages of follow up were 12.5% at 11 years, 14.4% at 15 years, and 18.7% at 18 years. Results: At 18 years, boys showed higher HbA1c than girls. At age 18 years, accelerometrybased PA at 18 years was inversely related to HbA1c levels in boys. Self-reported leisure-time PA at ages 11, 15, and 18 were unrelated to HbA1c in both genders. PA at 13 years of age was unrelated to HbA1c among both genders. In trajectory analysis, PA and accelerometer PA trajectories were not associated with later HbA1c. Conclusions: Objectively measured PA at 18 years was cross-sectionally inversely associated with HbA1c in boys only. No prospective associations were identified.

• Dalene, Knut Eirik; Anderssen, Sigmund Alfred; Andersen, Lars Bo; Steene-Johannessen, Jostein; Ekelund, Ulf & Hansen, Bjørge Hermann [Show all 7 contributors for this article] (2017). Secular and longitudinal physical activity changes in population-based samples of children and adolescents. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 28(1), p. 161–171. doi: 10.1111/sms.12876. Full text in Research Archive Show summary

  The aims of this study were to investigate whether physical activity (PA) and sedentary time (ST) in 9-and 15-year- olds differed between 2005-2006 and 2011-2012 (secular change), and to investigate changes in PA and ST from age 9 to 15 (longitudinal change). In 2005-2006, we invited nationally representative samples of Norwegian 9-( n=1470) and 15-year- olds (n=1348) to participate. In 2011-2012, we invited a new nationally representative sample of 9-year- olds (n=1945), whereas 15-year- olds (n=1759) were invited to participate either based on previous participation in 2005-2006 or from a random sample of schools. We assessed PA and ST objectively using accelerometers. In 2011-2012, both 9-and 15-year- olds spent more time sedentary (≥35.7 min/d, P<.001) and less time in light PA (≥35.2 min/d, P<.001) compared to their peers in 2005-2006. Nine-year- old girls also spent less time in moderate-to- vigorous PA (MVPA) (4.2 min/d, P=.041). In both age groups, the proportion accumulating an average of 60 min/d of MVPA did not differ between the two cohorts. From age 9 to 15, girls and boys decreased their time spent in LPA (≥106.7 min/d, P<.001) and in MVPA (≥20.8 min/d, P<.001). During the same period, ST increased by a mean of >2 h/d (P<.011). We observed an adverse secular change in PA from 2005-2006 to 2011-2012 among 9-and 15-year- olds, and a large decline in PA in the participants followed longitudinally from age 9 to 15 years.

• Færch, Kristine; Witte, Daniel Rinse; Brunner, Eric John; Kivimäki, Mika; Tabak, Adam & Jørgensen, Marit Eika [Show all 8 contributors for this article] (2017). Physical Activity and Improvement of Glycemia in Prediabetes by Different Diagnostic Criteria. Journal of Clinical Endocrinology and Metabolism (JCEM). ISSN 0021-972X. 102(10), p. 3712–3721. doi: 10.1210/jc.2017-00990. Full text in Research Archive Show summary

  Context: The effects of physical activity (PA) on improvement of glycemia may differ between prediabetic individuals defined by oral glucose tolerance test vs glycated hemoglobin (HbA1c). Objective: We studied the association between PA and improvement of glycemia in individuals with prediabetes defined by glucose vs HbA1c criteria. Design, Setting, and Participants: From the Whitehall II study, 957 participants ith prediabetes defined by isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), or both and 457 with prediabetes defined by HbA1c were included. Main Outcome Measures: The associations of PA with concomitant changes n glucose-related outcomes during 5 years of follow-up were analyzed. A recursive partitioning analysis was performed to study heterogeneity in the association between baseline PA and the prob ability of reversion to normoglycemia. Results: After 5 years of follow-up, 405 (42%) individuals with glucose-defined prediabetes reverted to normal glucose tolerance (NGT). A 5-year increase in moderate-to-vigorous-intensity PA was associated with improvements in insulin sensitivity and b-cell function, but PA was not generally associated with reversion to NGT. Only among women $50 years with i-IFG or i-IGT, higher amounts of PA were associated with higher probability of reversion to NGT. InHbA1c-defined prediabetes, only 20 individuals (4.4%) reverted to normoglycemia, and PA was not associated with improvement in glycemic markers. Conclusions: PA may be particularly important for reversion to normoglycemia among older women with i-IFG or i-IGT. Individuals with prediabetes identified by HbA1c have a low probability of reversion to normoglycemia, and their changes in glycemia are not related to PA.

• Dalene, Knut Eirik; Anderssen, Sigmund Alfred; Andersen, Lars Bo; Steene-Johannessen, Jostein; Ekelund, Ulf & Hansen, Bjørge Hermann [Show all 7 contributors for this article] (2017). Cross-sectional and prospective associations between physical activity, body mass index and waist circumference in children and adolescents. Obesity Science & Practice. 3(3), p. 249–257. doi: 10.1002/osp4.114. Full text in Research Archive Show summary

  Objective: To study the cross-sectional and prospective associations between physical activity (PA) of different intensities, body mass index (BMI) and waist circumference (WC) in children and adolescents using isotemporal substitution modelling. Methods: Physical activity (accelerometry), BMI and WC were assessed in 6- (n = 970), 9- (n = 2,423) and 15-year-olds (n = 1,544) in 2005/2006 and 2011/2012. Participants aged 9 years in 2005/2006 were followed prospectively to 2011/12 (age 15). Associations between PA of different intensities (light, moderate and vigorous), BMI and WC were examined using isotemporal substitution models. Results: Substituting 10 min per day of sedentary time with light PA was associated with higher WC (0.17 to 0.29 cm, p ≤ 0.003)) in all age groups. Substituting 10 min per day of sedentary time with moderate PA was associated with lower WC in 6- and 9-year-olds (−0.32 to −0.47 cm, p ≤ 0.013)). Substituting 10 min per day of sedentary time with vigorous PA was associated with lower WC in 9- and 15-year-olds (−1.08 to −1.79 cm, p ≤ 0.015)). Associations were similar with BMI as the outcome. In prospective analyses, substituting sedentary time with light, moderate or vigorous PA at age 9 was not associated with BMI or WC at age 15. Conclusion: Substituting sedentary time with moderate PA appears favourably associated with adiposity in children, whereas vigorous PA may be required in adolescents. Cross-sectional associations were not replicated in prospective analyses.

• Cureau, Felipe Vogt; Bloch, Katia Vergetti; Henz, Aline; Schaan, Camila W.; Klein, Carlos Henrique & Oliveira, Cecília Lacroix de [Show all 19 contributors for this article] (2017). Challenges for conducting blood collection and biochemical analysis in a large multicenter school-based study with adolescents: lessons from ERICA in Brazil. Cadernos de Saúde Pública. ISSN 0102-311X. 33(4), p. 1–12. doi: 10.1590/0102-311X00122816. Full text in Research Archive Show summary

  The Study of Cardiovascular Risk in Adolescents (ERICA) is a pioneering study that aimed to assess the prevalence of cardiovascular risk factors, including metabolic syndrome components in Brazilian adolescents. This study aims to describe the methodological aspects related to blood collection as well as to report pertaining results of the preparation, transport, storage, and exams in ERICA. Exams in ERICA were performed in a single laboratory and blood samples were collected in schools in a standardized manner. Logistics involved air transportation of samples to the reference laboratory with controlled temperature since sample collection. The serum was stored in local biorepositories in four centers to be used in future analyses. During the study, 284,247 exams were performed and rate of participation in exams was 56.2%, thus involving 40,732 adolescents. From the total, 92.6% of the samples reached the reference laboratory maintaining the temperature between 0-10°C. No clinical significant changes in results due to temperature changes were identified. External quality control recorded satisfactory results in 98.7% of the evaluations. Four biorepositories with samples of 7,785 adolescents were created. Thus, we can consider that the logistics adopted in ERICA was fairly successful and description of this as well as the difficulties experienced in Brazil can inform and facilitate the planning of future studies, especially in developing countries.

• Tarp, Jakob; Bugge, A.; Andersen, Lars Bo; Sardinha, Luis B.; Ekelund, Ulf & Brage, Søren [Show all 7 contributors for this article] (2017). Does adiposity mediate the relationship between physical activity and biological risk factors in youth?: a cross-sectional study from the International Children’s Accelerometry Database (ICAD). International Journal of Obesity. ISSN 0307-0565. 42(4), p. 671–678. doi: 10.1038/ijo.2017.241. Full text in Research Archive Show summary

  Background/Objectives: To model the association between accumulating 60 daily minutes of moderate-to-vigorous physical activity and a composite score of biological risk factors into a direct and an indirect effect, using abdominal obesity as the mediator. Subjects/Methods: Cross-sectional data from the International Children’s Accelerometry Database (ICAD) including 6–18-year-old children and adolescents (N=3412) from 4 countries providing at least 3 days of accelerometry-assessed physical activity. A standardized composite risk score was calculated from systolic blood pressure and fasting blood samples of insulin, glucose, triacylglycerol and inverse HDL-cholesterol. Abdominal obesity was assessed by the waist-circumference:height ratio. Two-stage regression analysis, allowing for exposure–mediator interaction, was used for the effect decomposition. Results: Participants achieving 60 daily minutes of moderate-to-vigorous physical activity had a 0.31 (95% CI: −0.39, −0.23) standard deviations lower composite risk score than those achieving less than 60 min. Modelling the associations suggested that 0.24 standard deviations (95% CI: −0.32, −0.16) was attributed to the direct effect and −0.07 (95% CI: −0.11, −0.02) to the indirect effect indicating that 22% of the total effect was mediated by central adiposity. Modelling 30 and 90 min of moderate-to-vigorous physical activity per day resulted in changes in the direct but not the indirect effect. Conclusions: One hour of daily moderate-to-vigorous physical activity was associated with clinically relevant differences in metabolic control compared to engagement in less than this minimally recommended amount. The majority of the difference was explained by the direct effect of physical activity.

• Loo, Christiana M.T. van; Okely, Anthony D.; Batterham, Marijka; Hinkley, Trina; Ekelund, Ulf & Brage, Søren [Show all 11 contributors for this article] (2017). Wrist Acceleration Cut-points for Moderate-to-Vigorous Physical Activity in Youth. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 50(3), p. 609–616. doi: 10.1249/MSS.0000000000001449. Full text in Research Archive Show summary

  Purpose: To examine the validity of wrist acceleration cut-points for classifying moderate (MPA), vigorous (VPA) and moderate-to-vigorous (MVPA) physical activity. Methods: Fifty-seven children (5-12y) completed 15 semi-structured activities. Three sets of wrist cutpoints (>192mg, >250mg, >314mg), previously developed using Euclidian norm minus one (ENMO192+), GENEActiv software (GENEA250+) and Bandpass Filtered followed by Euclidian Norm (BFEN314+), were evaluated against indirect calorimetry. Analyses included classification accuracy, equivalence testing and Bland-Altman procedures. Results: All cut-points classified MPA, VPA and MVPA with substantial accuracy (ENMO192+: κ = 0.72 [95% confidence interval: 0.72 – 0.73], MVPA: area under the receiver operating characteristic curve (ROC-AUC) = 0.85 [0.85 – 0.86]; GENEA250+: κ = 0.75 [0.74 – 0.76], MVPA: ROC-AUC = 0.85 [0.85 – 0.86]; BFEN314+: κ = 0.73 [0.72 – 0.74], MVPA: ROC-AUC = 0.86 [0.86 – 0.87]). BFEN314+ misclassified 19.7% non-MVPA epochs as MPA, whereas ENMO192+ and GENEA250+ misclassified 32.6% and 26.5% of MPA epochs as non-MVPA, respectively. Group estimates of MPA time were equivalent (p<0.01) to indirect calorimetry for the BFEN314+ MPA cut-point (mean bias: -1.5%, limits of agreement [LoA]: -57.5 - 60.6%), while estimates of MVPA time were equivalent (p<0.01) to indirect calorimetry for the ENMO192+ (mean bias: -1.1% [LoA: - 53.7% – 55.9%]) and GENEA250+ (mean bias: 2.2% [LoA: -56.5% – 52.2%]) cut-points. Individual variability (LoAs) was large for MPA (min: BFEN314+, -60.6% – 57.5%; max: GENEA250+, -42.0% – 104.1%), VPA (min: BFEN314+, -238.9% – 54.6%; max: ENMO192+, - 244.5% – 127.4%) and MVPA (min: ENMO192+, -53.7% – 55.0%; max: BFEN314+, -83.9% – 25.3%). Conclusion: Wrist acceleration cut-points misclassified a considerable proportion of non-MVPA and MVPA. Group level estimates of MVPA were acceptable; however, error for individual level prediction was larger.

• García-Hermoso, Antonio; Saavedra, Jose M.; Ramírez-Vélez, Robinson; Ekelund, Ulf & Pozo-Cruz, Borja Del (2017). Reallocating sedentary time to moderate-to-vigorous physical activity but not to light-intensity physical activity is effective to reduce adiposity among youths: a systematic review and meta-analysis. Obesity Reviews. ISSN 1467-7881. 18(9), p. 1088–1095. doi: 10.1111/obr.12552. Full text in Research Archive Show summary

  The aim of the study was to summarize the evidence of the effects of reallocating time spent in sedentary behaviours in different activity intensities on youth's adiposity. Five databases were searched. Studies that reported the effects of replacing sedentary behaviour with light-intensity physical activity (LIPA) and/or moderate-to-vigorous physical activity (MVPA) on at least one adiposity parameter. The estimated regression coefficients (β) and 95% CIs were combined and meta-analysed. Data from 7,351 youths and five studies were analysed. Pooled analysis from cross-sectional studies shows that replacing sedentary time with LIPA showed no significant associations with any adiposity-related outcomes. Replacing sedentary time with MVPA was statistically associated with total body fat percentage (β = −2.512; p = 0.003), but not with body mass index or waist circumference. In subgroup analysis, the greatest magnitude of association was observed from studies where 60 min of sedentary behaviour was reallocated to 60 min of MVPA (β = −4.535; p < 0.001). Our results highlight the importance of promoting MVPA, which may improve body composition phenotypes in young people. This information can be used to develop more effective lifestyle interventions.

• Silva, Inacio C.M. Da; Hino, Adriano Akira; Lopes, Adalberto; Ekelund, Ulf; Brage, Søren & Goncalves, Helen [Show all 9 contributors for this article] (2017). Built environment and physical activity: domain- and activity-specific associations among Brazilian adolescents. BMC Public Health. 17(1). doi: 10.1186/s12889-017-4538-7. Full text in Research Archive Show summary

  Background: Physical activity is likely to be determined as a complex interplay between personal, interpersonal, and environmental factors. Studying the built environment involves expanding the focus from the individual perspective to a public health one. Therefore, the objetive of this study was to examine the association between the built environment and objectively-measured physical activity among youth. Methods: Cross-sectional analysis of data from of a Brazilian birth cohort during adolescence. Physical activity was measured using accelerometers (GENEActiv) and self-report (International Physical Activity Questionnaire, long version). Participants’ home addresses were geocoded and built environment characteristics such as streets’ pattern and quality, and public open spaces attributes for physical activity practice were evaluated in a 500-m circular buffer surrounding their homes. Results: A total of 3379 participants were included. Street lighting (β = 2.2; 95%CI: 0.5; 3.9) was positively associated with objectively-measured moderate-vigorous physical activity (MVPA) and proportion of paved streets and buffer’s average family income were associated with lower MVPA. Living near the beach increased the odds of leisure-time MVPA practice by 3.3 (95%CI: 1.37; 8.02) times. There was a built environment-by-socioeconomic status (SES) interaction for the associations with commuting physical activity; street lighting [Odds ratio (OR) = 1.22; 95%CI: 1.01; 1.47] and presence of cycle lanes (OR = 1.77; 95%CI: 1.05; 2.96) were positively associated with commuting physical activity only among the intermediate SES tertile. Conclusion: Beachfront, street lighting, paved streets and cycle lanes were associated with physical activity patterns. This suggests that infrastructure interventions may influence physical activity levels of Brazilian adolescents.

• Griffin, Tania L; Clarke, Joanne L; Lancashire, Emma R.; Pallan, Miranda J.; Adab, Peymane & Barrett, Tim [Show all 19 contributors for this article] (2017). Process evaluation results of a cluster randomised controlled childhood obesity prevention trial: the WAVES study. BMC Public Health. 17. doi: 10.1186/s12889-017-4690-0. Full text in Research Archive Show summary

  Background: Increasing prevalence of childhood obesity and its related consequences emphasises the importance of developing and evaluating interventions aimed at prevention. The importance of process evaluation in health intervention research is increasingly recognised, assessing implementation and participant response, and how these may relate to intervention success or failure. A comprehensive process evaluation was designed and undertaken for the West Midlands ActiVe lifestyle and healthy Eating in School children (WAVES) study that tested the effectiveness of an obesity prevention programme for children aged 6-7 years, delivered in 24 UK schools. The four intervention components were: additional daily school-time physical activity (PA); cooking workshops for children and parents; Villa Vitality (VV), a 6-week healthy lifestyle promotion programme run by a local football club; and signposting to local PA opportunities. Methods: Data relating to six dimensions (Fidelity, Reach, Recruitment, Quality, Participant Responsiveness, Context) were collected via questionnaires, logbooks, direct observations, focus groups and interviews. Multiple data collection methods allowed for data triangulation and validation of methods, comparing research observations with teacher records. The 6-stage WAVES study model ((i) Data collection, (ii) Collation, (iii) Tabulation, (iv) Score allocation and discussion, (v) Consultation, (vi) Final score allocation) was developed to guide the collection, assimilation and analysis of process evaluation data. Two researchers independently allocated school scores on a 5-point Likert scale for each process evaluation dimension. Researchers then discussed school score allocations and reached a consensus. Schools were ranked by total score, and grouped to reflect low, medium or high intervention implementation. Results: The intervention was predominantly well-implemented and well-received by teachers, parents and children. The PA component was identified as the most challenging, VV the least. Median implementation score across schools was 56/75 (IQR, 51.0 - 60.8). Agreement between teacher logbooks and researcher observations was generally high, the main discrepancies occurred in session duration reporting where in some cases teachers’ estimations tended to be higher than researchers’. Conclusions: The WAVES study model provides a rigorous and replicable approach to undertaking and analysing a multi-component process evaluation. Challenges to implementing school-based obesity prevention interventions have been identified which can be used to inform future trials.

• Aadland, Eivind; Andersen, Lars Bo; Skrede, Turid; Ekelund, Ulf; Anderssen, Sigmund Alfred & Resaland, Geir Kåre (2017). Reproducibility of objectively measured physical activity and sedentary time over two seasons in children; Comparing a day-by-day and a week-by-week approach. PLOS ONE. 12(12). doi: 10.1371/journal.pone.0189304. Full text in Research Archive Show summary

  Introduction Knowledge of reproducibility of accelerometer-determined physical activity (PA) and sedentary time (SED) estimates are a prerequisite to conduct high-quality epidemiological studies. Yet, estimates of reproducibility might differ depending on the approach used to analyze the data. The aim of the present study was to determine the reproducibility of objectively measured PA and SED in children by directly comparing a day-by-day and a week-by-week approach to data collected over two weeks during two different seasons 3–4 months apart. Methods 676 11-year-old children from the Active Smarter Kids study conducted in Sogn og Fjordane county, Norway, performed 7 days of accelerometer monitoring (ActiGraph GT3X+) during January-February and April-May 2015. Reproducibility was calculated using a day-by-day and a week-by-week approach applying mixed effect modelling and the Spearman Brown prophecy formula, and reported using intra-class correlation (ICC), Bland Altman plots and 95% limits of agreement (LoA). Results Applying a week-by-week approach, no variables provided ICC estimates ≥ 0.70 for one week of measurement in any model (ICC = 0.29–0.66 not controlling for season; ICC = 0.49–0.67 when controlling for season). LoA for these models approximated a factor of 1.3–1.7 of the sample PA level standard deviations. Compared to the week-by-week approach, the day-by-day approach resulted in too optimistic reliability estimates (ICC = 0.62–0.77 not controlling for season; ICC = 0.64–0.77 when controlling for season). Conclusions Reliability is lower when analyzed over different seasons and when using a week-by-week approach, than when applying a day-by-day approach and the Spearman Brown prophecy formula to estimate reliability over a short monitoring period. We suggest a day-by-day approach and the Spearman Brown prophecy formula to determine reliability be used with caution.

• Loo, Christiana M.T. van; Okely, Anthony D.; Batterham, Marijka; Hinkley, Trina; Ekelund, Ulf & Brage, Søren [Show all 11 contributors for this article] (2017). Wrist Accelerometer Cut-points for Classifying Sedentary Behavior in Children. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 49(4), p. 813–822. doi: 10.1249/MSS.0000000000001158. Full text in Research Archive Show summary

  Introduction: To examine the validity and accuracy of wrist accelerometers for classifying sedentary behavior (SB) in children. Methods: Fifty-seven children (5-8y and 9-12y) completed a ~170min protocol including 15 semi-structured activities and transitions. Nine ActiGraph (GT3X+) and two GENEActiv wrist cut-points were evaluated. Direct observation was the criterion measure. The accuracy of wrist cut-points was compared to that achieved by the ActiGraph hip cut-point (≤25 counts/15s) and the thigh-mounted activPAL3TM. Analyses included equivalence testing, Bland-Altman procedures and area under the receiver operating curve (ROC-AUC). Results: The most accurate ActiGraph wrist cut-points (Kim, vector magnitude: ≤3958 counts/60s and vertical axis: ≤1756 counts/60s) demonstrated good classification accuracy (ROC-AUC = 0.85-0.86) and accurately estimated SB time in 5-8y (equivalence p=0.02; mean bias: 4.1%, limits of agreement [LoA]: -20.1-28.4%) and 9-12y (equivalence p<0.01; -2.5%, -27.9-22.9%). Mean bias of SB time estimates from Kim were smaller than ActiGraph hip (5-8y: 15.8%, -5.7-37.2%; 9-12y: 17.8%, -3.9-39.5%) and similar to or smaller than activPAL3TM (5-8y: 12.6%, -39.8-14.7%; 9-12y: -1.4%, -13.9-11.0%), although classification accuracy was similar to ActiGraph hip (ROC-AUC = 0.85) but lower than activPAL3TM (ROC-AUC = 0.92-0.97). Mean bias (5-8y: 6.5%, -16.1-29.1%; 9-12y: 10.5%, - 13.6-34.6%) for the most accurate GENEActiv wrist cut-point (Schaefer: ≤0.19g) was smaller than ActiGraph hip, and activPAL3TM in 5-8y, but larger than activPAL3TM in 9-12y. However, SB time estimates from Schaefer were not equivalent to direct observation (equivalence p>0.05) and classification accuracy (ROC-AUC = 0.79-0.80) was lower than for ActiGraph hip and activPAL3TM. Conclusion: The most accurate SB ActiGraph (Kim) and GENEActiv (Schaefer) wrist cut-points can be applied in children with similar confidence as the ActiGraph hip cut-point (≤25 counts/15s), although activPAL3TM was generally more accurate.

• Ekelund, Ulf; Kolle, Elin; Steene-Johannessen, Jostein; Dalene, Knut Eirik; Nilsen, Ada Kristine Ofrim & Anderssen, Sigmund Alfred [Show all 7 contributors for this article] (2017). Objectively measured sedentary time and physical activity and associations with body weight gain: does body weight determine a decline in moderate and vigorous intensity physical activity? International Journal of Obesity. ISSN 0307-0565. 41(12), p. 1769–1774. doi: 10.1038/ijo.2017.186. Full text in Research Archive Show summary

  OBJECTIVES: High levels of physical activity (PA) may prevent the development of obesity. However, the magnitude and direction of the association between PA of various intensities, sedentary time and weight status remain unclear. Thus, we examined whether objectively measured sedentary time and PA independently predict gain in body weight, change in body weight and to examine the possibility of reverse causation. METHODS: We examined the prospective associations between sedentary time, PA and body weight (BW). Baseline measurements were conducted in 2008/2009 and follow-up measurements in 2014/2015 in a random sample of the adult Norwegian population (N = 1710, 45.1% men). Moderate and vigorous intensity PA (MVPA) and sedentary time were measured by accelerometry and BW and height self-reported. We first modelled the associations between baseline sedentary time and PA with BW at follow-up. We then modelled the reverse associations (BW as the exposure) and sedentary time and PA (as outcomes) in separate models. All models were adjusted for age, sex, baseline value of the outcome, socio-economic status, alcohol consumption, smoking, monitor wear time and follow-up time. RESULTS: Body mass index (BMI) increased by 0.2 units (P = 0.003) between baseline and follow-up, and 46.5% of participants were either overweight (36.4%) or obese (10.1%) at baseline increasing to 49.6% (11.7% obese) at follow-up. Baseline sedentary time, MVPA and vigorous PA were not associated with BW at follow-up after adjustment for covariates. In contrast, baseline BW was inversely associated with MVPA (β = − 0.11; 95% confidence interval (CI); − 0.21, − 0.009) and VPA (β = − 0.035; 95% CI; − 0.059, − 0.011) in adjusted models. These associations were unchanged when BW was substituted by BMI. CONCLUSIONS: Baseline BW seems to determine a decrease in MVPA in healthy adult Norwegian men and women, more so than the reverse.

• Júdice, Pedro B.; Silva, Analiza Mónica Onica; Berria, Juliane; Petroski, Edio L.; Ekelund, Ulf & Sardinha, Luís B. (2017). Sedentary patterns, physical activity and health-related physical fitness in youth: A cross-sectional study. International Journal of Behavioral Nutrition and Physical Activity. 14(25). doi: 10.1186/s12966-017-0481-3. Full text in Research Archive Show summary

  Background: Strong evidence indicates that moderate-vigorous physical activity (MVPA) is positively associated with fitness in youth, independent of total sedentary-time. Sedentary-time appears negatively associated with fitness only when it replaces MVPA. However, whether different sedentary-patterns affect health-related fitness is unknown. Methods: The associations between MVPA and sedentary-patterns with physical fitness were examined in 2698 youths (1262 boys) aged 13.4 ± 2.28 years. Sedentary-time (counts · minute−1 < 100) and PA were objectively measured by accelerometry. Each break (≥100 counts · min−1 < 2295) in sedentary-time and the frequency of daily bouts in non-prolonged (<30 min) and prolonged (≥30 min) sedentary-time were determined. The FITNESSGRAM® test battery was used to assess fitness. A standardized fitness composite-score (z-score) was calculated by summing the individual z-scores of the five tests adjusted to age and sex. Results: Positive associations between MVPA and fitness were observed in both boys (β = 0.013, 95% CI: 0.005; 0.021) and girls (β = 0.014, 95% CI: 0.006; 0.022), independent of sedentary-patterns. Modest associations were found for the breaks in sedentary-time with fitness (β = 0.026, 95% CI: 0.009; 0.042), independent of total sedentary-time and MVPA in boys. In girls, non-prolonged sedentary bouts were positively associated with fitness (β = 0.014, 95% CI: 0.003; 0.024), independent of total sedentary-time and MVPA. Conclusions: These results reinforce that, independent of the time and patterns of sedentary behavior, MVPA is consistently associated with fitness in youth. Modest and inconsistent associations were found for sedentary behaviors. Breaking-up sedentary-time in boys and non-prolonged sedentary bouts in girls were positively associated with fitness, independent of total sedentary-time and MVPA. In order to enhance youth’s fitness, public health recommendations should primarily target MVPA, still, suggestion to reduce and break-up sedentary-time may also be considered.

• Harris, Tess; Kerry, Sally M.; Limb, Elizabeth S.; Victor, Christina R.; Iliffe, Steve & Ussher, Michael [Show all 18 contributors for this article] (2017). Effect of a Primary Care Walking Intervention with and without Nurse Support on Physical Activity Levels in 45- to 75-Year-Olds: The Pedometer And Consultation Evaluation (PACE-UP) Cluster Randomised Clinical Trial. PLoS Medicine. ISSN 1549-1277. 14(1). doi: 10.1371/journal.pmed.1002210. Full text in Research Archive Show summary

  Background: Pedometers can increase walking and moderate-to-vigorous physical activity (MVPA) levels, but their effectiveness with or without support has not been rigorously evaluated. We assessed the effectiveness of a pedometer-based walking intervention in predominantly inactive adults, delivered by post or through primary care nurse-supported physical activity (PA) consultations. Methods and Findings: A parallel three-arm cluster randomised trial was randomised by household, with 12-mo follow-up, in seven London, United Kingdom, primary care practices. Eleven thousand fifteen randomly selected patients aged 45–75 y without PA contraindications were invited. Five hundred forty-eight self-reporting achieving PA guidelines were excluded. One thousand twenty-three people from 922 households were randomised between 2012–2013 to one of the following groups: usual care (n = 338); postal pedometer intervention (n = 339); and nurse-supported pedometer intervention (n = 346). Of these, 956 participants (93%) provided outcome data (usual care n = 323, postal n = 312, nurse-supported n = 321). Both intervention groups received pedometers, 12-wk walking programmes, and PA diaries. The nurse group was offered three PA consultations. Primary and main secondary outcomes were changes from baseline to 12 mo in average daily step-counts and time in MVPA (in ≥10-min bouts), respectively, measured objectively by accelerometry. Only statisticians were masked to group. Analysis was by intention-to-treat. Average baseline daily step-count was 7,479 (standard deviation [s.d.] 2,671), and average time in MVPA bouts was 94 (s.d. 102) min/wk. At 12 mo, mean steps/d, with s.d. in parentheses, were as follows: control 7,246 (2,671); postal 8,010 (2,922); and nurse support 8,131 (3,228). PA increased in both intervention groups compared with the control group; additional steps/d were 642 for postal (95% CI 329–955) and 677 for nurse support (95% CI 365–989); additional MVPA in bouts (min/wk) were 33 for postal (95% CI 17–49) and 35 for nurse support (95% CI 19–51). There were no significant differences between the two interventions at 12 mo. The 10% (1,023/10,467) recruitment rate was a study limitation. Conclusions: A primary care pedometer-based walking intervention in predominantly inactive 45- to 75-y-olds increased step-counts by about one-tenth and time in MVPA in bouts by about one-third. Nurse and postal delivery achieved similar 12-mo PA outcomes. A primary care pedometer intervention delivered by post or with minimal support could help address the public health physical inactivity challenge.

• Ramires, Virgílio Viana; Wehrmeister, Fernando César; Böhm, Andrea Wendt; Galliano, Leony; Ekelund, Ulf & Brage, Soren [Show all 7 contributors for this article] (2017). Physical activity levels objectively measured among older adults: A population-based study in a Southern city of Brazil. International Journal of Behavioral Nutrition and Physical Activity. 14(13). doi: 10.1186/s12966-017-0465-3. Full text in Research Archive Show summary

  Background: Low levels of physical activity are currently observed in all age groups around the world. Among older adults physical activity is even lower, potentially influencing quality of life, incidence of diseases and premature mortality. The aim of this study was to describe objectively measured physical activity levels among older adults residents in a Southern city of Brazil. Methods: A population-based study was carried out including people aged 60+ years living in the urban area of Pelotas. Face-to-face interviews, anthropometric measures and triaxial accelerometry (non-dominant wrist) were used to collect sociodemographic, anthropometric and physical activity, respectively. For descriptive purposes, overall physical activity was expressed as daily averages of acceleration. Time spent in light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) using different bout criteria (non-bouted, and in 1-, 5- and 10-min bouts) were calculated. Crude and adjusted analyses were performed using simple linear regression to examine the association between physical activity and exposure variables. Results: Overall, 971 individuals provided valid accelerometry data. Women spent on average more time on LPA (136.2 vs. 127.6 min per day). Men and women respectively accumulated, in average, 64.5 and 56.7 min per day of non-bouted MVPA, while these daily averages were 14.9 and 9.46 min using 5-min, and 8.1 and 4.5 min using 10-min bout MVPA. In adjusted analyses, men aged 80 years or more spent in average 45 min less LPA per day when compared to men 60-69 years and, among women, this difference was 65 min. Considering time in 5-min MVPA bouts, the youngest age group and those with a better self-perceived health accumulated more MVPA. Specifically among men, socioeconomic status was inversely associated with 5-min bout MVPA. Conclusion: The present study showed low levels of physical activity among Brazilian older adults, even lower in more advanced ages, and a different pattern for physical activity intensity between men and women.

• Loo, Christiana M.T. van; Okely, Anthony D.; Batterham, Marijka; Hinkley, Trina; Ekelund, Ulf & Brage, Søren [Show all 11 contributors for this article] (2017). Validation of the SenseWear Mini activity monitor in 5−12-year-old children. Journal of Science and Medicine in Sport. ISSN 1440-2440. 20(1), p. 55–59. doi: 10.1016/j.jsams.2016.04.010. Full text in Research Archive Show summary

  Objectives: This study aimed to validate SenseWear Mini software algorithm versions 2.2 (SW2.2) and 5.2 (SW5.2) for estimating energy expenditure (EE) in children. Design: Laboratory-based validation study. Methods: 57 children aged 5−12 y completed a protocol involving 15 semi-structured sedentary (SED), light-intensity (LPA), and moderate- to vigorous-intensity (MVPA) physical activities. EE was estimated using portable indirect calorimetry (IC). The accuracy of EE estimates (kcal·min−1) from SW2.2 and SW5.2 were examined at the group level and individual level using the mean absolute percentage error (MAPE), Bland-Altman plots and equivalence testing. Results: MAPE values were lower for SW5.2 (30.1 ± 10.7%) than for SW2.2 (44.0 ± 6.2%). Although mean differences for SW5.2 were smaller than for SW2.2 during SED (−0.23 ± 0.22 vs. −0.61 ± 0.20 kcal·min−1), LPA (−0.69 ± 0.76 vs. −1.07 ± 0.46 kcal·min−1) and MVPA (−2.22 ± 1.15 vs. −2.57 ± 1.15 kcal·min−1), limits of agreement did not decrease for the updated algorithms. For all activities, SW2.2 and SW5.2 were not equivalent to IC (p > 0.05). Errors increased with increasing intensity. Conclusion: The current SenseWear Mini algorithms SW5.2 underestimated EE. The overall improved accuracy for SW5.2 was not accompanied with improved accuracy at the individual level and EE estimates were not equivalent to IC.

• Knuth, Alan G.; Silva, Inácio Crochemore M.; Hees, Vincent T. van; Cordeira, Kelly L.; Matijasevich, Alícia & Barros, Aluísio J. D. [Show all 9 contributors for this article] (2017). Objectively-measured physical activity in children is influenced by social indicators rather than biological lifecourse factors: Evidence from a Brazilian cohort. Preventive Medicine. ISSN 0091-7435. 97, p. 40–44. doi: 10.1016/j.ypmed.2016.12.051. Full text in Research Archive Show summary

  The aim of this study was to examine the longitudinal influences of early life social and biological indicators on objectively measured physical activity. All newborns in 2004 in the city of Pelotas, Southern Brazil were enrolled in a birth cohort study. At the age of 6 years, a follow-up visit included objective assessment of overall physical activity (summarized in milli-g, 1 mg = 0.001 g) by tri-axial wrist worn accelerometry. The associations between early life exposures, such as type of delivery, parity, birth weight, preterm delivery, maternal physical activity, socioeconomic position, and overall physical activity were examined. Valid accelerometry data were obtained from 2604 children (78.2% of the eligible individuals). Girls were less active than boys (β = − 8.65 mg; 95% CI − 10.0; − 7.30). Higher socioeconomic position was related to lower activity levels (β = − 9.69 mg. 95% CI − 12.45; − 6.93) and a similar association was found with maternal schooling. No associations were found with birthweight, type of delivery or preterm delivery. This study provides evidence for the role of some social factors in explaining children's physical activity behaviors, and minimizes the influence of some early life biological factors at determining physical activity levels.

• Atkin, Andrew J; Biddle, Stuart JH; Broyles, Stephanie T; Chinapaw, Mai; Ekelund, Ulf & Esliger, Dale W. [Show all 25 contributors for this article] (2017). Harmonising data on the correlates of physical activity and sedentary behaviour in young people: Methods and lessons learnt from the international Children's Accelerometry database (ICAD). International Journal of Behavioral Nutrition and Physical Activity. 14(1). doi: 10.1186/s12966-017-0631-7. Full text in Research Archive Show summary

  Background Large, heterogeneous datasets are required to enhance understanding of the multi-level influences on children’s physical activity and sedentary behaviour. One route to achieving this is through the pooling and co-analysis of data from multiple studies. Where this approach is used, transparency of the methodology for data collation and harmonisation is essential to enable appropriate analysis and interpretation of the derived data. In this paper, we describe the acquisition, management and harmonisation of non-accelerometer data in a project to expand the International Children’s Accelerometry Database (ICAD). Method Following a consultation process, ICAD partners were requested to share accelerometer data and information on selected behavioural, social, environmental and health-related constructs. All data were collated into a single repository for cataloguing and harmonisation. Harmonised variables were derived iteratively, with input from the ICAD investigators and a panel of invited experts. Extensive documentation, describing the source data and harmonisation procedure, was prepared and made available through the ICAD website. Results Work to expand ICAD has increased the number of studies with longitudinal accelerometer data, and expanded the breadth of behavioural, social and environmental characteristics that can be used as exposure variables. A set of core harmonised variables, including parent education, ethnicity, school travel mode/duration and car ownership, were derived for use by the research community. Guidance documents and facilities to enable the creation of new harmonised variables were also devised and made available to ICAD users. An expanded ICAD database was made available in May 2017. Conclusion The project to expand ICAD further demonstrates the feasibility of pooling data on physical activity, sedentary behaviour and potential determinants from multiple studies. Key to this process is the rigorous conduct and reporting of retrospective data harmonisation, which is essential to the appropriate analysis and interpretation of derived data. These documents, made available through the ICAD website, may also serve as a guide to others undertaking similar projects.

• Tremblay, Mark S.; Aubert, Salomé; Barnes, Joel D.; Saunders, Travis J.; Carson, Valerie & Latimer-Cheung, Amy E. [Show all 10 contributors for this article] (2017). Sedentary Behavior Research Network (SBRN) - Terminology Consensus Project process and outcome. International Journal of Behavioral Nutrition and Physical Activity. 14:75, p. 1–17. doi: 10.1186/s12966-017-0525-8. Full text in Research Archive
• Medin, Anine Christine; Hansen, Bjørge Hermann; Astrup, Helene; Ekelund, Ulf & Andersen, Lene Frost (2017). Validation of energy intake from a web-based food recall for children and adolescents. PLOS ONE. 12(6). doi: 10.1371/journal.pone.0178921. Full text in Research Archive Show summary

  The purpose of this study was to validate estimated energy intake from a web-based food recall, designed for children and adolescents. We directly compared energy intake to estimates of total energy expenditure, calculated from accelerometer outputs, combined with data on weight and sex or resting energy expenditure prediction equations. Children (8–9 years) and adolescents (12–14 years) were recruited through schools in Norway in 2013 (N = 253). Results showed that more than one third (36–37%) were identified as under-reporters of energy. In contrast, only 2–4% were defined as over-reporters of energy. The mean energy intake was under-reported with -1.83 MJ/day for the entire study sample. Increased underestimation was observed for overweight and obese participants, the oldest age group (12–14 years), boys, those with parents/legal guardians with low educational level and those living in non-traditional families. In conclusion, energy intake from the web-based food recall is significantly underestimated compared with total energy expenditure, and should be used with caution in young people.

• Bentham, James; Cesare, Mariachiara Di; Bilano, Ver; Bixby, Honor; Zhou, Bin & Stevens, Gretchen A. [Show all 110 contributors for this article] (2017). Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults. The Lancet. ISSN 0140-6736. 390(10113), p. 2627–2642. doi: 10.1016/S0140-6736(17)32129-3. Full text in Research Archive Show summary

  Background Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults. Methods We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5–19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5–19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity). Findings Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (−0·01 kg/m2 per decade; 95% credible interval −0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69–1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64–1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (−0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50–1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4–1·2) in 1975 to 5·6% (4·8–6·5) in 2016 in girls, and from 0·9% (0·5–1·3) in 1975 to 7·8% (6·7–9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0–12·9) in 1975 to 8·4% (6·8–10·1) in 2016 in girls and from 14·8% (10·4–19·5) in 1975 to 12·4% (10·3–14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7–29·6) among girls and 30·7% (23·5–38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44–117) million girls and 117 (70–178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24–89) million girls and 74 (39–125) million boys worldwide were obese. Interpretation The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults.

• Kuzik, Nicholas; Carson, Valerie; Andersen, Lars Bo; Sardinha, Luís B.; Grøntved, Anders & Hansen, Bjørge Hermann [Show all 7 contributors for this article] (2017). Physical Activity and Sedentary Time Associations with Metabolic Health Across Weight Statuses in Children and Adolescents. Obesity. ISSN 1930-7381. 25(10), p. 1762–1769. doi: 10.1002/oby.21952. Full text in Research Archive Show summary

  Objective: The aim of this study was to examine the prevalence of metabolic health across weight statuses and the associations of physical activity and sedentary time within and across metabolic health-weight status groups. Methods: Six studies (n = 4,581) from the International Children's Accelerometry Database were used. Sedentary time, light physical activity, and moderate to vigorous physical activity (MVPA) were accelerometer derived. Individuals were classified with normal weight (NW), overweight, or obesity. Strict and lenient composite definitions of metabolic health were created. Binomial and multinomial logistic regressions controlling for age, sex, study, and accelerometer wear time were conducted. Results: The metabolically unhealthy (MU) prevalence was 26.4% and 45.6% based on two definitions. Across definitions, more sedentary time was associated with higher odds of MU classification compared with metabolically healthy (MH) classification for the NW group. More MVPA was associated with lower odds of MU classification than MH classification for NW and overweight groups. For multinomial logistic regressions, more MVPA was associated with lower odds of MH-obesity classification, as well as MU-NW, -overweight, and -obesity classifications, compared with the MH-NW group. Furthermore, more sedentary time was associated with higher odds of MU-NW classification compared with the MH-NW group. Conclusions: More MVPA was beneficial for metabolic health and weight status, whereas lower sedentary time was beneficial for metabolic health alone, although associations were weak.

• Haapala, Eero A.; Väistö, Juuso; Veijalainen, Aapo; Lintu, Niina; Wiklund, Petri & Westgate, Kate [Show all 10 contributors for this article] (2017). Associations of Objectively Measured Physical Activity and Sedentary Time With Arterial Stiffness in Pre-Pubertal Children. Pediatric Exercise Science. ISSN 0899-8493. 29(3), p. 326–335. doi: 10.1123/pes.2016-0168. Full text in Research Archive Show summary

  Purpose: To investigate the relationships of objectively measured physical activity (PA) and sedentary time (ST) to arterial stiffness in prepubertal children. Method: Altogether 136 children (57 boys, 79 girls) aged 6–8-years participated in the study. Stiffness index (SI) was assessed by pulse contour analysis based on photoplethysmography. ST, light PA, moderate PA, and vigorous PA were assessed using combined acceleration and heart rate monitoring. We investigated the associations of ST (<1.5METs) and time spent in intensity level of PA above 2–7METs in min/d with SI using linear regression analysis. We studied the optimal duration and intensity of PA to identify children being in the highest quarter of SI using Receiver Operating Characteristics curves. Results: Moderate PA, vigorous PA, and cumulative time spent in PA above 3 (β=–0.279, p = .002), 4 (β =–0.341, P<0.001), 5 (β =–0.349, P<0.001), 6 (β =–0.312, P<0.001), and 7 (β =–0.254, p = .005) METs were inversely associated with SI after adjustment for age, sex, and monitor wear time. The cutoffs for identifying children being in the highest quarter of SI <68 min/d for PA exceeding 5 METs and <26 min/d for PA exceeding 6 METs. Conclusion: Lower levels of PA exceeding 3–6 METs were related to higher arterial stiffness in children.

• Hildebrand, Maria; Hansen, Bjørge Hermann; Hees, Vincent T. van & Ekelund, Ulf (2017). Evaluation of raw acceleration sedentary thresholds in children and adults. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 27(12), p. 1814–1823. doi: 10.1111/sms.12795. Full text in Research Archive Show summary

  The aim was to develop sedentary (sitting/lying) thresholdsfrom hip and wrist worn raw tri-axial acceleration datafrom the ActiGraph and GENEActiv, and to examine theagreement between free-living time spent below thesethresholds with sedentary time estimated by the activPAL.Sixty children and adults wore an ActiGraph andGENEActiv on the hip and wrist while performing sixstructured activities, before wearing the monitors, inaddition to an activPAL, for 24 h. Receiver operatingcharacteristic (ROC) curves were used to determinesedentary thresholds based on activities in the laboratory.Agreement between developed sedentary thresholds duringfree-living and activPAL were assessed by Bland-Altmanplots and by calculating sensitivity and specificity. Usinglaboratory data and ROC-curves showed similarclassification accuracy for wrist and hip thresholds(Area under the curve = 0.84–0.92). Greatest sensitivity(97–98%) and specificity (74–78%) were observed forthe wrist thresholds, with no large differences betweenbrands. During free-living, Bland-Altman plots showedlarge mean individual biases and 95% limits of agreementcompared with activPAL, with smallest difference for theActiGraph wrist threshold in children (+30 min, P = 0.3).Sensitivity and specificity for the developedthresholds during free-living were low for both age groupsand for wrist (Sensitivity, 68–88%, Specificity, 46–59%)and hip placements (Sensitivity, 89–97%, Specificity,26–34%). Laboratory derived sedentary thresholdsgenerally overestimate free-living sedentary timecompared with activPAL. Wrist thresholds appear toperform better than hip thresholds for estimating free-living sedentary time in children and adults relative toactivPAL, however, specificity for all the developedthresholds are low.

• Skrede, Turid; Stavnsbo, Mette; Aadland, Eivind; Aadland, Katrine Nyvoll; Anderssen, Sigmund Alfred & Resaland, Geir Kåre [Show all 7 contributors for this article] (2017). Moderate-to-vigorous physical activity, but not sedentary time, predicts changes in cardiometabolic risk factors in 10-y-old children: The Active Smarter Kids Study. American Journal of Clinical Nutrition. ISSN 0002-9165. 105(6), p. 1391–1398. doi: 10.3945/ajcn.116.150540. Full text in Research Archive Show summary

  Background: Cross-sectional data have suggested an inverse relation between physical activity and cardiometabolic risk factors that is independent of sedentary time. However, little is known about which subcomponent of physical activity may predict cardiometabolic risk factors in youths. Objective: We examined the independent prospective associations between objectively measured sedentary time and subcomponents of physical activity with individual and clustered cardiometabolic risk factors in healthy children aged 10 y. Design: We included 700 children (49.1% males; 50.9% females) in which sedentary time and physical activity were measured with the use of accelerometry. Systolic blood pressure, waist circumference (WC), and fasting blood sample (total cholesterol, high-density lipoprotein cholesterol, triglycerides, glucose, fasting insulin) were measured with the use of standard clinical methods and analyzed individually and as a clustered cardiometabolic risk score standardized by age and sex (z score). Exposure and outcome variables were measured at baseline and at follow-up 7 mo later. Results: Sedentary time was not associated with any of the individual cardiometabolic risk factors or clustered cardiometabolic risk in prospective analyses. Moderate physical activity at baseline predicted lower concentrations of triglycerides (P = 0.021) and homeostatic model assessment for insulin resistance (P = 0.027) at follow-up independent of sex, socioeconomic status, Tanner stage, monitor wear time, or WC. Moderate-to-vigorous physical activity (P = 0.043) and vigorous physical activity (P = 0.028) predicted clustered cardiometabolic risk at follow-up, but these associations were attenuated after adjusting for WC. Conclusions: Physical activity, but not sedentary time, is prospectively associated with cardiometabolic risk in healthy children. Public health strategies aimed at improving children’s cardiometabolic profile should strive for increasing physical activity of at least moderate intensity rather than reducing sedentary time. This trial was registered at clinicaltrials.gov as NCT02132494.

• Sardinha, Luís B.; Marques, Adilson; Minderico, Cláudia S. & Ekelund, Ulf (2017). Cross-sectional and prospective impact of reallocating sedentary time to physical activity on children’s body composition. Pediatric Obesity. ISSN 2047-6302. 12(5), p. 373–379. doi: 10.1111/ijpo.12153. Full text in Research Archive Show summary

  Background: The amount of time children spend in sedentary behaviours may have adverse health effects. Objective: To examine the substitution effects of displacing a fixed duration of sedentary time with physical activity (PA) on children’s body composition. Methods: We included 386 children (197 boys). Outcomes were body mass index, waist circumference, total body fat mass and trunk fat mass assessed by dual-energy X-ray absorptiometry. Sedentary time and PA were measured with ac- celerometers. Data were analysed by isotemporal analyses estimating the effect of reallocating 15 and 30 min d 1 of sedentary time into light (light physical activity), and moderate-to-vigorous (MVPA) PA on body composition. Results: Reallocating 15 and 30 min d 1 of sedentary time into MVPA was nega- tively associated with body fatness in cross-sectional analyses. Prospectively, reallocating 30 min of sedentary time into 30 min of MVPA was negatively associ- ated with waist circumference (β = 1.11, p < 0.05), trunk fat mass (β = 0.21, p < 0.05), and total body fat mass (β = 0.48, p < 0.05) at follow-up (20 months). The magnitude of associations was half in magnitude and remained significant (p < 0.05) when reallocating 15 min of sedentary time into MVPA. Reallocating sed- entary time into light physical activity was not related (p > 0.05) with body fatness outcomes. Conclusions: Substituting sedentary time with MVPA using isotemporal analysis is associated with positive effects on body composition.

• Migueles, Jairo H.; Cadenas-Sanchez, Cristina; Ekelund, Ulf; Nyström, Christine Delisle; Mora-Gonzalez, Jose & Löf, Marie [Show all 9 contributors for this article] (2017). Accelerometer data collection and processing criteria to assess physical activity and other outcomes: a systematic review and practical considerations. Sports Medicine. ISSN 0112-1642. 47(9), p. 1821–1845. doi: 10.1007/s40279-017-0716-0. Full text in Research Archive Show summary

  Background: Accelerometers are widely used to measure sedentary time, physical activity, physical activity energy expenditure (PAEE), and sleep-related behaviors, with the ActiGraph being the most frequently used brand by researchers. However, data collection and processing criteria have evolved in a myriad of ways out of the need to answer unique research questions; as a result there is no consensus. Objectives: The purpose of this review was to: (1) compile and classify existing studies assessing sedentary time, physical activity, energy expenditure, or sleep using the ActiGraph GT3X/+ through data collection and processing criteria to improve data comparability and (2) review data collection and processing criteria when using GT3X/+ and provide age-specific practical considerations based on the validation/calibration studies identified. Methods: Two independent researchers conducted the search in PubMed and Web of Science. We included all original studies in which the GT3X/+ was used in laboratory, controlled, or free-living conditions published from 1 January 2010 to the 31 December 2015. Results: The present systematic review provides key information about the following data collection and processing criteria: placement, sampling frequency, filter, epoch length, non-wear-time, what constitutes a valid day and a valid week, cut-points for sedentary time and physical activity intensity classification, and algorithms to estimate PAEE and sleep-related behaviors. The information is organized by age group, since criteria are usually age-specific. Conclusion: This review will help researchers and practitioners to make better decisions before (i.e., device placement and sampling frequency) and after (i.e., data processing criteria) data collection using the GT3X/+ accelerometer, in order to obtain more valid and comparable data.

• Loo, Christiana M.T. van; Okely, Anthony D.; Batterham, Marijka; Hinkley, Tina; Ekelund, Ulf & Brage, Søren [Show all 11 contributors for this article] (2016). Predictive Validity of a Thigh-Worn Accelerometer METs Algorithm in 5- to 12-Year-old Children. Journal of Physical Activity and Health. ISSN 1543-3080. 13(6), p. S78–S83. doi: 10.1123/jpah.2015-0721. Full text in Research Archive Show summary

  Background: To validate the activPAL3 algorithm for predicting metabolic equivalents (TAMETs) and classifying MVPA in 5- to 12-year-old children. Methods: Fifty-seven children (9.2 ± 2.3y, 49.1% boys) completed 14 activities including sedentary behaviors (SB), light (LPA) and moderate-to-vigorous physical activities (MVPA). Indirect calorimetry (IC) was used as the criterion measure. Analyses included equivalence testing, Bland-Altman procedures and area under the receiver operating curve (ROC-AUC). Results: At the group level, TAMETs were significantly equivalent to IC for handheld e-game, writing/coloring, and standing class activity (P < .05). Overall, TAMETs were overestimated for SB (7.9 ± 6.7%) and LPA (1.9 ± 20.2%) and underestimated for MVPA (27.7 ± 26.6%); however, classification accuracy of MVPA was good (ROC-AUC = 0.86). Limits of agreement were wide for all activities, indicating large individual error (SB: –27.6% to 44.7%; LPA: –47.1% to 51.0%; MVPA: –88.8% to 33.9%). Conclusions: TAMETs were accurate for some SB and standing, but were overestimated for overall SB and LPA, and underestimated for MVPA. Accuracy for classifying MVPA was, however, acceptable.

• Cesare, Mariachiara Di; Bentham, James; Stevens, Gretchen A; Zhou, Bin; Danaei, Goodarz & Lu, Yuan [Show all 740 contributors for this article] (2016). Trends in adult body-mass index in 200 countries from 1975 to 2014: A pooled analysis of 1698 population-based measurement studies with 19.2 million participants. The Lancet. ISSN 0140-6736. 387(10026), p. 1377–1396. doi: 10.1016/S0140-6736(16)30054-X. Full text in Research Archive Show summary

  Background Underweight and severe and morbid obesity are associated with highly elevated risks of adverse health outcomes. We estimated trends in mean body-mass index (BMI), which characterises its population distribution, and in the prevalences of a complete set of BMI categories for adults in all countries. Methods We analysed, with use of a consistent protocol, population-based studies that had measured height and weight in adults aged 18 years and older. We applied a Bayesian hierarchical model to these data to estimate trends from 1975 to 2014 in mean BMI and in the prevalences of BMI categories (<18·5 kg/m2 [underweight], 18·5 kg/m2 to <20 kg/m2, 20 kg/m2 to <25 kg/m2, 25 kg/m2 to <30 kg/m2, 30 kg/m2 to <35 kg/m2, 35 kg/m2 to <40 kg/m2, ≥40 kg/m2 [morbid obesity]), by sex in 200 countries and territories, organised in 21 regions. We calculated the posterior probability of meeting the target of halting by 2025 the rise in obesity at its 2010 levels, if post-2000 trends continue. Findings We used 1698 population-based data sources, with more than 19·2 million adult participants (9·9 million men and 9·3 million women) in 186 of 200 countries for which estimates were made. Global age-standardised mean BMI increased from 21·7 kg/m2 (95% credible interval 21·3–22·1) in 1975 to 24·2 kg/m2 (24·0–24·4) in 2014 in men, and from 22·1 kg/m2 (21·7–22·5) in 1975 to 24·4 kg/m2 (24·2–24·6) in 2014 in women. Regional mean BMIs in 2014 for men ranged from 21·4 kg/m2 in central Africa and south Asia to 29·2 kg/m2 (28·6–29·8) in Polynesia and Micronesia; for women the range was from 21·8 kg/m2 (21·4–22·3) in south Asia to 32·2 kg/m2 (31·5–32·8) in Polynesia and Micronesia. Over these four decades, age-standardised global prevalence of underweight decreased from 13·8% (10·5–17·4) to 8·8% (7·4–10·3) in men and from 14·6% (11·6–17·9) to 9·7% (8·3–11·1) in women. South Asia had the highest prevalence of underweight in 2014, 23·4% (17·8–29·2) in men and 24·0% (18·9–29·3) in women. Age-standardised prevalence of obesity increased from 3·2% (2·4–4·1) in 1975 to 10·8% (9·7–12·0) in 2014 in men, and from 6·4% (5·1–7·8) to 14·9% (13·6–16·1) in women. 2·3% (2·0–2·7) of the world's men and 5·0% (4·4–5·6) of women were severely obese (ie, have BMI ≥35 kg/m2). Globally, prevalence of morbid obesity was 0·64% (0·46–0·86) in men and 1·6% (1·3–1·9) in women. Interpretation If post-2000 trends continue, the probability of meeting the global obesity target is virtually zero. Rather, if these trends continue, by 2025, global obesity prevalence will reach 18% in men and surpass 21% in women; severe obesity will surpass 6% in men and 9% in women. Nonetheless, underweight remains prevalent in the world's poorest regions, especially in south Asia.

• Ekelund, Ulf; Steene-Johannessen, Jostein; Brown, Wendy J.; Fagerland, Morten; Owen, Neville & Powell, Kenneth E. [Show all 8 contributors for this article] (2016). Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women. The Lancet. ISSN 0140-6736. 388(10051), p. 1302–1310. doi: 10.1016/S0140-6736(16)30370-1. Full text in Research Archive Show summary

  Background: High amounts of sedentary behaviour have been associated with increased risks of several chronic conditions and mortality. However, it is unclear whether physical activity attenuates or even eliminates the detrimental eff ects of prolonged sitting. We examined the associations of sedentary behaviour and physical activity with all-cause mortality. Methods: We did a systematic review, searching six databases (PubMed, PsycINFO, Embase, Web of Science, Sport Discus, and Scopus) from database inception until October, 2015, for prospective cohort studies that had individual level exposure and outcome data, provided data on both daily sitting or TV-viewing time and physical activity, and reported eff ect estimates for all-cause mortality, cardiovascular disease mortality, or breast, colon, and colorectal cancer mortality. We included data from 16 studies, of which 14 were identifi ed through a systematic review and two were additional unpublished studies where pertinent data were available. All study data were analysed according to a harmonised protocol, which categorised reported daily sitting time and TV-viewing time into four standardised groups each, and physical activity into quartiles (in metabolic equivalent of task [MET]-hours per week). We then combined data across all studies to analyse the association of daily sitting time and physical activity with all-cause mortality, and estimated summary hazard ratios using Cox regression. We repeated these analyses using TV-viewing time instead of daily sitting time. Findings: Of the 16 studies included in the meta-analysis, 13 studies provided data on sitting time and all-cause mortality. These studies included 1 005 791 individuals who were followed up for 2–18·1 years, during which 84 609 (8·4%) died. Compared with the referent group (ie, those sitting <4 h/day and in the most active quartile [>35·5 MET-h per week]), mortality rates during follow-up were 12–59% higher in the two lowest quartiles of physical activity (from HR=1·12, 95% CI 1·08–1·16, for the second lowest quartile of physical activity [<16 MET-h per week] and sitting <4 h/day; to HR=1·59, 1·52–1·66, for the lowest quartile of physical activity [<2·5 MET-h per week] and sitting >8 h/day). Daily sitting time was not associated with increased all-cause mortality in those in the most active quartile of physical activity. Compared with the referent (<4 h of sitting per day and highest quartile of physical activity [>35·5 MET-h per week]), there was no increased risk of mortality during follow-up in those who sat for more than 8 h/day but who also reported >35·5 MET-h per week of activity (HR=1·04; 95% CI 0·99–1·10). By contrast, those who sat the least (<4 h/day) and were in the lowest activity quartile (<2·5 MET-h per week) had a signifi cantly increased risk of dying during follow-up (HR=1·27, 95% CI 1·22–1·31). Six studies had data on TV-viewing time (N=465 450; 43 740 deaths). Watching TV for 3 h or more per day was associated with increased mortality regardless of physical activity, except in the most active quartile, where mortality was signifi cantly increased only in people who watched TV for 5 h/day or more (HR=1·16, 1·05–1·28). Interpretation: High levels of moderate intensity physical activity (ie, about 60–75 min per day) seem to eliminate the increased risk of death associated with high sitting time. However, this high activity level attenuates, but does not eliminate the increased risk associated with high TV-viewing time. These results provide further evidence on the benefits of physical activity, particularly in societies where increasing numbers of people have to sit for long hours for work and may also inform future public health recommendations.

• Steene-Johannessen, Jostein; Anderssen, Sigmund Alfred; Ploeg, Hidde P van der; Hendriksen, Ingrid; Donnelly, Alan & Brage, Søren [Show all 7 contributors for this article] (2016). Are self-report measures able to define individuals as physically active or inactive? Medicine & Science in Sports & Exercise. ISSN 0195-9131. 48(2), p. 235–244. doi: 10.1249/MSS.0000000000000760. Full text in Research Archive Show summary

  Purpose: Assess the agreement between commonly used self-report methods compared with objectively measured physical activity (PA) in defining the prevalence of individuals compliant with PA recommendations. Methods: Time spent in moderate and vigorous PA (MVPA) was measured at two time points in 1713 healthy individuals from 9 European countries using individually-calibrated combined heart-rate and movement sensing. Participants also completed the Recent Physical Activity Questionnaire (RPAQ), the short form of the International Physical Activity Questionnaire (IPAQ) and the short European Prospective Investigation into Cancer and Nutrition Physical Activity Questionnaire (EPIC-PAQ). Individuals were categorized as active (e.g. reporting >=150 min of MVPA per week) or inactive, based on the information derived from the different measures. Sensitivity and specificity analyses and Kappa statistics were performed to evaluate the three PAQs ability to correctly categorize individuals as active or inactive. Results: Prevalence estimates of being sufficiently active varied significantly (p for all <0.001) between self-report measures (IPAQ 84.2 % [95% CI 82.5 to 85.9], RPAQ 87.6% [95% CI 85.9 to 89.1], EPIC-PAQ 39.9% [95% CI 37.5 to 42.1] and objective measure 48.5% [95% CI 41.6 to 50.9]. All self-report methods showed low or moderate sensitivity (IPAQ 20.0 %, RPAQ 18.7% and EPIC-PAQ 69.8%) to correctly classify inactive people and the agreement between objective and self-reported PA was low ([latin kra] =0.07 [95% CI 0.02 to 0.12], 0.12 [95% CI 0.06 to 0.18] and 0.19 [95% CI 0.13 to 0.24] for IPAQ, RPAQ, and EPIC-PAQ, respectively). Conclusion: The modest agreement between self-reported and objectively measured PA suggests that population levels of PA derived from self-report should be interpreted cautiously. Implementation of objective measures in large-scale cohort studies and surveillance systems is recommended.

• Tikanmäki, Marjaana; Tammelin, Tuija H.; Kaseva, Nina; Sipola-Leppänen, Marika; Matinolli, Hanna-Maria & Hakonen, Harto [Show all 11 contributors for this article] (2016). Objectively measured physical activity and sedentary time in young adults born preterm - The ESTER study. Pediatric Research. ISSN 0031-3998. 81(4), p. 550–555. doi: 10.1038/pr.2016.262. Full text in Research Archive Show summary

  Background: Young adults born preterm have higher levels of cardiometabolic risk factors and they report less physical activity than their peers born at term. Physical activity provides important cardiometabolic health benefits. We hypothesized that objectively measured physical activity levels are lower and time spent sedentary is higher among preterm-born individuals compared to controls. Methods: We studied unimpaired participants of the ESTER birth cohort study at age 23.3 years (SD: 1.2): 60 born early preterm (<34 weeks), 108 late preterm (34-36 weeks), and 178 at term (controls). Physical activity and sedentary time were measured by hip-worn accelerometer (ActiGraph®). Results: As compared with controls’ (mean physical activity, 303 counts per minute (cpm; SD 129)), physical activity was similar among adults born early preterm (mean difference=21 cpm, 95%CI -61, 19) or late preterm (5 cpm, -27, 38). Time spent sedentary was also similar. Adjustments for early life confounders or current mediating characteristics did not change the results. Conclusion: In contrast to our hypothesis, we found no difference in objectively measured physical activity or time spent sedentary between adults born preterm and at term. The previously reported differences may be limited to physical activity captured by self-report.

• Cureau, Felipe Vogt; Silva, Thiago Luiz Nogueira da; Bloch, Katia Vergetti; Fujimori, Elizabeth; Belfort, Dilson Rodrigues & Carvalho, Kênia Mara Baiocchi de [Show all 10 contributors for this article] (2016). ERICA: leisure-time physical inactivity in Brazilian adolescents. Revista de Saude Publica. ISSN 0034-8910. 50, p. 1s–11s. doi: 10.1590/S01518-8787.2016050006683. Full text in Research Archive Show summary

  OBJECTIVE: To evaluate the prevalence of leisure-time physical inactivity in Brazilian adolescents and their association with geographical and sociodemographic variables. METHODS: The sample was composed by 74,589 adolescents participating in the Study of Cardiovascular Risks in Adolescents (ERICA). This cross-sectional study of school basis with national scope involved adolescents aged from 12 to 17 years in Brazilian cities with more than 100 thousand inhabitants. The prevalence of leisure-time physical inactivity was categorized according to the volume of weekly practice (< 300; 0 min). The prevalences were estimated for the total sample and by sex. Poisson regression models were used to assess associated factors. RESULTS: The prevalence of leisure-time physical inactivity was 54.3% (95%CI 53.4-55.2), and higher for the female sex (70.7%, 95%CI 69.5-71.9) compared to the male (38.0%, 95%CI 36.7-39.4). More than a quarter of adolescents (26.5%, 95%CI 25.8-27.3) reported not practicing physical activity in the leisure time, a condition more prevalent for girls (39.8%, 95%CI 38.8-40.9) than boys (13.4%, 95%CI 12.4-14.4). For girls, the variables that were associated with physical inactivity were: reside in the Northeast (RP = 1.13, 95%CI 1.08-1.19), Southeast (RP = 1.16, 95%CI 1.11-1.22) and South (RP = 1.12, 95%CI 1.06-1.18); have 16-17 years (RP = 1.06, 95%CI 1.12-1.15); and belong to the lower economic class (RP = 1.33, 95%CI 1.20-1.48). The same factors, except reside in the Southeast and South, were also associated with not practicing physical activity in the leisure time for the same group. In males, as well as the region, being older (p < 0.001) and declaring to be indigenous (RP = 0.37, 95%CI 0.19-0.73) were also associated with not practicing physical activities in the leisure time. CONCLUSIONS: The prevalence of leisure-time physical inactivity in Brazilian adolescents is high. It presents regional variations and is associated with age and low socioeconomic status. Special attention should be given to girls and to those who do not engage in any physical activity during the leisure time, so that they can adopt a more active lifestyle.

• Atkin, Andrew J.; Foley, Louise; Corder, Kirsten; Ekelund, Ulf & Sluijs, Esther M.F. van (2016). Determinants of Three-Year Change in Children’s Objectively Measured Sedentary Time. PLOS ONE. 11(12). doi: 10.1371/journal.pone.0167826. Full text in Research Archive Show summary

  Background: Sedentary behaviours (SB) are highly prevalent in young people and may be adversely associated with physical and mental health. Understanding of the modifiable determinants of SB is necessary to inform the design of behaviour change interventions but much of the existing research is cross-sectional and focussed upon screen-based behaviours. Purpose: To examine the social, psychological and environmental determinants of change in children's objectively measured sedentary time from age 11 to 14 years. Methods: Data are from the second (2008) and third (2011) waves of assessment in the Sport, Physical Activity, and Eating Behaviour: Environmental Determinants in Young People (SPEEDY) study, conducted in the county of Norfolk, United Kingdom. Longitudinal data on accelerometer assessed sedentary time were available for 316 (53.5% female, 11.2±0.3 years at baseline) and 264 children after-school and at the weekend respectively. Information on 14 candidate determinants, including school travel mode and electronic media ownership, was self-reported. Change in the proportion of registered time spent sedentary was used as the outcome variable in cross-classified linear regression models, adjusted for age, sex, body mass index and baseline sedentary time. Simple and multiple models were run and interactions with sex explored. Results: Daily sedentary time increased by 30±40 minutes after-school and at the weekend from baseline to follow-up. Participants who travelled to school by cycle exhibited smaller increases in after-school sedentary time (beta; 95%CI for change in%time spent sedentary: -3.3;-6.7,-0.07). No significant determinants of change in weekend sedentary time were identified. Conclusions: Time spent sedentary increased during the three-year duration of follow-up but few of the variables examined were significantly associated with changes in sedentary time. Children's mode of school travel may influence changes in their sedentary time over this period and should be examined further, alongside broader efforts to identify modifiable determinants of SB during childhood.

• Nightingale, C.M.; Donin, A.S.; Kerry, S.R.; Owen, C.G.; Rudnicka, Alicja R & Brage, Søren [Show all 10 contributors for this article] (2016). Cross-sectional study of ethnic differences in physical fitness among children of South Asian, black African–Caribbean and white European origin: the Child Heart and Health Study in England (CHASE). BMJ Open. 6(6). doi: 10.1136/bmjopen-2016-011131. Full text in Research Archive Show summary

  Objective: Little is known about levels of physical fitness in children from different ethnic groups in the UK. We therefore studied physical fitness in UK children (aged 9–10 years) of South Asian, black African–Caribbean and white European origin. Design: Cross-sectional study. Setting: Primary schools in the UK. Participants: 1625 children (aged 9–10 years) of South Asian, black African–Caribbean and white European origin in the UK studied between 2006 and 2007. Outcome measures: A step test assessed submaximal physical fitness from which estimated VO2 max was derived. Ethnic differences in estimated VO2 max were estimated using multilevel linear regression allowing for clustering at school level and adjusting for age, sex and month as fixed effects. Results: The study response rate was 63%. In adjusted analyses, boys had higher levels of estimated VO2 max than girls (mean difference 3.06 mL O2/min/ kg, 95% CI 2.66 to 3.47, p<0.0001). Levels of estimated VO2 max were lower in South Asians than those in white Europeans (mean difference −0.79 mL O2/min/kg, 95% CI −1.41 to −0.18, p=0.01); levels of estimated VO2 max in black African–Caribbeans were higher than those in white Europeans (mean difference 0.60 mL O2/min/kg, 95% CI 0.02 to 1.17, p=0.04); these patterns were similar in boys and girls. The lower estimated VO2 max in South Asians, compared to white Europeans, was consistent among Indian, Pakistani and Bangladeshi children and was attenuated by 78% after adjustment for objectively measured physical activity (average daily steps). Conclusions: South Asian children have lower levels of physical fitness than white Europeans and black African–Caribbeans in the UK. This ethnic difference in physical fitness is at least partly explained by ethnic differences in physical activity.

• Hecke, Linde Van; Loyen, Anne; Verloigne, Maïté; Ploeg, Hidde P. van der; Lakerveld, Jeroen & Brug, Johannes [Show all 11 contributors for this article] (2016). Variation in population levels of physical activity in European children and adolescents according to cross-European studies: a systematic literature review within DEDIPAC. International Journal of Behavioral Nutrition and Physical Activity. 13(1). doi: 10.1186/s12966-016-0396-4. Full text in Research Archive Show summary

  Background: Regular physical activity is associated with physical, social and mental health benefits, whilst insufficient physical activity is associated with several negative health outcomes (e.g. metabolic problems). Population monitoring of physical activity is important to gain insight into prevalence of compliance to physical activity recommendations, groups at risk and changes in physical activity patterns. This review aims to provide an overview of all existing studies that measure physical activity in youth, in cross-European studies, to describe the variation in population levels of physical activity and to describe and define challenges regarding assessment methods that are used. Methods: A systematic search was performed on six databases (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey), supplemental forward- and backward tracking was done and authors’ and experts’ literature databases were searched to identify relevant articles. Journal articles or reports that reported levels of physical activity in the general population of youth from cross-European studies were included. Data were reviewed, extracted and assessed by two researchers, with disagreements being resolved by a third researcher. The review protocol of this review is published under registration number CRD42014010684 in the PROSPERO database. Results: The search resulted in 9756 identified records of which 30 articles were included in the current review. This review revealed large differences between countries in prevalence of compliance to physical activity recommendations (i.e. 60 min of daily moderate- to vigorous-intensity physical activity (MVPA)) measured subjectively (5–47 %) and accelerometer measured minutes of MVPA (23–200 min). Overall boys and children were more active than girls and adolescents. Different measurement methods (subjective n = 12, objective n = 18) and reported outcome variables (n = 17) were used in the included articles. Different accelerometer intensity thresholds used to define MVPA resulted in substantial differences in MVPA between studies conducted in the same countries when assessed objectively. Conclusions: Reported levels of physical activity and prevalence of compliance to physical activity recommendations in youth showed large variation across European countries. This may reflect true variation in physical activity as well as variation in assessment methods and reported outcome variables. Standardization across Europe, of methods to assess physical activity in youth and reported outcome variables is warranted, preferably moving towards a pan-European surveillance system combining objective and self-report methods.

• Loo, Christiana M.T. van; Okely, Anthony D.; Batterham, Marijka; Hinkley, Trina; Ekelund, Ulf & Brage, Søren [Show all 10 contributors for this article] (2016). Validation of thigh-based accelerometer estimates of postural allocation in 5–12 year-olds. Journal of Science and Medicine in Sport. ISSN 1440-2440. 20(3), p. 273–277. doi: 10.1016/j.jsams.2016.08.008. Full text in Research Archive Show summary

  Objectives: To validate activPAL3TM(AP3) for classifying postural allocation, estimating time spent inpostures and examining the number of breaks in sedentary behaviour (SB) in 5–12 year-olds.Design: Laboratory-based validation study.Methods: Fifty-seven children completed 15 sedentary, light- and moderate-to-vigorous intensity activi-ties. Direct observation (DO) was used as the criterion measure. The accuracy of AP3 was examined usinga confusion matrix, equivalence testing, Bland–Altman procedures and a paired t-test for 5–8y and 9–12y.Results: Sensitivity of AP3 was 86.8%, 82.5% and 85.3% for sitting/lying, standing, and stepping, respec-tively, in 5–8y and 95.3%, 81.5% and 85.1%, respectively, in 9–12y. Time estimates of AP3 were equivalentto DO for sitting/lying in 9–12y and stepping in all ages, but not for sitting/lying in 5–12y and standingin all ages. Underestimation of sitting/lying time was smaller in 9–12y (1.4%, limits of agreement [LoA]:−13.8 to 11.1%) compared to 5–8y (12.6%, LoA: −39.8 to 14.7%). Underestimation for stepping time wassmall (5–8y: 6.5%, LoA: −18.3 to 5.3%; 9–12y: 7.6%, LoA: −16.8 to 1.6%). Considerable overestimation wasfound for standing (5–8y: 36.8%, LoA: −16.3 to 89.8%; 9–12y: 19.3%, LoA: −1.6 to 36.9%). SB breaks weresignificantly overestimated (5–8y: 53.2%, 9–12y: 28.3%, p < 0.001).Conclusions: AP3 showed acceptable accuracy for classifying postures, however estimates of time spentstanding were consistently overestimated and individual error was considerable. Estimates of sit-ting/lying were more accurate for 9–12y. Stepping time was accurately estimated for all ages. SB breakswere significantly overestimated, although the absolute difference was larger in 5–8y. Surveillance appli-cations of AP3 would be acceptable, however, individual level applications might be less accurate.

• Corder, Kirsten; Sharp, Stephen J.; Atkin, Andrew J.; Andersen, Lars Bo; Cardon, Greet & Page, Angie S. [Show all 16 contributors for this article] (2016). Age-related patterns of vigorous-intensity physical activity in youth: The International Children's Accelerometry Database. Preventive Medicine Reports. 4, p. 17–22. doi: 10.1016/j.pmedr.2016.05.006. Full text in Research Archive Show summary

  Physical activity declines during youth but most evidence reports on combined moderate and vigorous-intensity physical activity. We investigated how vigorous-intensity activity varies with age. Cross-sectional data from 24,025 participants (5.0–18.0 y; from 20 studies in 10 countries obtained 2008–2010) providing ≥ 1 day accelerometer data (International Children's Accelerometry Database (ICAD)). Linear regression was used to investigate age-related patterns in vigorous-intensity activity; models included age (exposure), adjustments for monitor wear-time and study. Moderate-intensity activity was examined for comparison. Interactions were used to investigate whether the age/vigorous-activity association differed by sex, weight status, ethnicity, maternal education and region. A 6.9% (95% CI 6.2, 7.5) relative reduction in mean vigorous-intensity activity with every year of age was observed; for moderate activity the relative reduction was 6.0% (5.6%, 6.4%). The age-related decrease in vigorous-intensity activity remained after adjustment for moderate activity. A larger age-related decrease in vigorous activity was observed for girls (− 10.7%) versus boys (− 2.9%), non-white (− 12.9% to − 9.4%) versus white individuals (− 6.1%), lowest maternal education (high school (− 2.0%)) versus college/university (ns) and for overweight/obese (− 6.1%) versus healthy-weight participants (− 8.1%). In addition to larger annual decreases in vigorous-intensity activity, overweight/obese individuals, girls and North Americans had comparatively lower average vigorous-intensity activity at 5.0–5.9 y. Age-related declines in vigorous-intensity activity during youth appear relatively greater than those of moderate activity. However, due to a higher baseline, absolute moderate-intensity activity decreases more than vigorous. Overweight/obese individuals, girls, and North Americans appear especially in need of vigorous-intensity activity promotion due to low levels at 5.0–5.9 y and larger negative annual differences.

• Collings, Paul J.; Wijndaele, Katrien; Corder, Kirsten; Westgate, Kate; Ridgway, Charlotte L. & Sharp, Stephen J. [Show all 12 contributors for this article] (2016). Objectively measured physical activity and longitudinal changes in adolescent body fatness: an observational cohort study. Pediatric Obesity. ISSN 2047-6302. 11(2), p. 107–114. doi: 10.1111/ijpo.12031. Full text in Research Archive Show summary

  Background: The data regarding prospective associations between physical activity (PA) and adiposity in youth are inconsistent. Objective: The objective of this study was to investigate associations between baseline levels of objectively measured PA and changes in adiposity over 2.5 years from mid-to-late adolescence. Methods: This was an observational cohort study in 728 school students (43% boys) from Cambridgeshire, United Kingdom. Fat mass index (FMI, kg m−2) was estimated at baseline (mean ± standard deviation age: 15 ± 0.3 years) and follow-up (17.5 ± 0.3 years) by anthropometry and bioelectrical impedance. Habitual PA was assessed at baseline by ≥3 d combined heart rate and movement sensing. Average daily PA energy expenditure (PAEE) and the time (min d−1) spent in light, moderate and vigorous intensity PA (LPA, MPA and VPA, respectively) was estimated. Multilevel models were used to investigate associations between baseline PA and change in FMI (ΔFMI). Adjustment for baseline age, sex, follow-up duration, area-level socioeconomic status, season of PA assessment, sedentary time, energy intake and sleep duration was made; baseline FMI was also added in a second model. Results: FMI increased significantly over follow-up (0.6 ± 1.2 kg m−2, P < 0.001). Baseline PAEE and LPA positively predicted ΔFMI in overfat participants (P ≤ 0.030), as did VPA in initially normal fat participants (P ≤ 0.044). There were further positive associations between PAEE and ΔFMI in normal fat participants, and between MPA and ΔFMI in both fat groups, when adjusted for baseline FMI (P ≤ 0.024). Conclusions: Baseline PAEE and its subcomponents were positively associated with small and unlikely clinically relevant increases in ΔFMI. These counter-intuitive findings may be explained by behavioural changes during the course of study follow-up.

• Bentham, James; Cesare, Mariachiara Di; Stevens, Gretchen A.; Zhou, Bin; Bixby, Honor & Cowan, Melanie [Show all 794 contributors for this article] (2016). A century of trends in adult human height. eLIFE. 5. doi: 10.7554/elife.13410. Full text in Research Archive
• Sardinha, Luís B.; Marques, Adilson; Minderico, Cláudia S.; Palmeira, António; Martins, Sandra B. & Santos, Diana A. [Show all 7 contributors for this article] (2016). Longitudinal relationship between cardiorespiratory fitness and academic achievement. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 48(5), p. 839–844. doi: 10.1249/MSS.0000000000000830. Full text in Research Archive Show summary

  Purpose: The aim of this study was to examine the prospective associations between cardiorespiratory fitness (CRF) and academic achievement in the youth. Methods: The sample included 1286 fifth-, sixth-, and seventh-grade students, age 11 to 14 yr (Mage = 11.3 T 1.1), from 14 schools followed for 3 yr. Academic achievement was assessed using the students_ marks at baseline and at follow-up 3 yr apart, in Portuguese, mathematics, foreign language (English), and science. CRF was assessed by the Progressive Aerobic Cardiovascular Endurance Run test from the Fitnessgrambattery. Studentswere classified as fit–fit, unfit–fit, fit–unfit, and unfit–unfit according to the Progressive Aerobic Cardiovascular Endurance Run test results at baseline and follow-up. Ordinal regression analyses were performed to examine associations between CRF and academic achievement. Results: Being persistently fit (fit–fit), compared with those classified unfit–unfit, increased the odds of having high levels of academic achievement in Portuguese (odds ratio (OR) = 3.49; 95% CI, 1.97–6.20; P G 0.001) and foreign language (OR = 2.41; 95% CI, 1.39–4.14; P G 0.01) at follow-up. Students that improved their CRF and became fit (unfit–fit) had also higher odds of achieving better marks than those persistently unfit–unfit in Portuguese (OR = 2.52; 95% CI, 1.42–4.45; P G 0.01) and foreign language (OR = 2.13; 95% CI, 1.23–3.67; P G 0.01). Conclusion: Consistently high and improvements in cardiorespiratory fitness are prospectively associated with better academic achievement especially in mother tongue and foreign language.

• Haapala, Eero A.; Väistö, Juuso; Lintu, Niina; Westgate, Kate L.; Ekelund, Ulf & Poikkeus, Anna-Maija [Show all 8 contributors for this article] (2016). Physical activity and sedentary time in relation to academic achievement in children. Journal of Science and Medicine in Sport. ISSN 1440-2440. 20(6), p. 583–589. doi: 10.1016/j.jsams.2016.11.003. Full text in Research Archive Show summary

  Objectives: To investigate the independent and combined associations of objectively measured moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) with reading and arithmetic skills. Design: Cross-sectional/prospective. Methods: Participants were 89 boys and 69 girls aged 6–8 years. MVPA and ST were measured using a combined heart rate and movement sensor and body fat percentage by dual-energy X-ray absorptiometry in Grade 1. Reading fluency, reading comprehension, and arithmetic skills were assessed using standardized tests in Grades 1–3. The data were analyzed using linear regression analyses and analyses of covariance with repeated measures. Results: In boys, MVPA was directly and ST inversely associated with reading fluency in Grades 1–3 and arithmetic skills in Grade 1 (P < 0.05). Higher levels of MVPA were also related to better reading comprehension in Grade 1 (P < 0.05). Most of the associations of MVPA and ST with reading and arithmetic skills attenuated after mutual adjustment for MVPA or ST. Furthermore, boys with a combination of lower levels of MVPA and higher levels of ST had consistently poorer reading fluency (P = 0.002) and reading comprehension (P = 0.027) across Grades 1–3 than other boys. In girls, ST was directly associated with arithmetic skills in Grade 2 (P < 0.05). However, this relationship of ST with arithmetic skills was no longer significant after adjustment for body fat percentage. Conclusions: Lower levels of MVPA and higher levels of ST and particularly their combination were related to poorer reading skills in boys. In girls, higher levels of ST were related to better arithmetic skills.

• Sardinha, Luis B.; Cyrino, Edilson S.; Santos, Leandro dos; Ekelund, Ulf & Santos, Diana (2016). Fitness but not weight status is associated with projected physical independence in older adults. Age. ISSN 0161-9152. 38(3). doi: 10.1007/s11357-016-9911-4. Full text in Research Archive Show summary

  Obesity and fitness have been associated with older adults’ physical independence. We aimed to investigate the independent and combined associations of physical fitness and adiposity, assessed by body mass index (BMI) and waist circumference (WC) with the projected ability for physical independence. A total of 3496 non-institutionalized older adults aged 65 and older (1167 male) were included in the analysis. BMI and WC were assessed and categorized according to established criteria. Physical fitness was evaluated with the Senior Fitness Test and individual test results were expressed as Z-scores. Projected ability for physical independence was assessed with the 12-item composite physical function scale. Logistic regression was used to estimate the odds ratio (OR) for being physically dependent. A total of 30.1 % of participants were classified as at risk for losing physical independence at age 90 years. Combined fitness and fatness analysis demonstrated that unfit older adults had increased odds ratio for being physically dependent in all BMI categories (normal: OR = 9.5, 95 %CI = 6.5–13.8; overweight: OR = 6.0, 95 %CI = 4.3–8.3; obese: OR = 6.7, 95 %CI = 4.6–10.0) and all WC categories (normal: OR = 10.4, 95%CI = 6.5–16.8; middle: OR = 6.2, 95 %CI = 4.1–9.3; upper: OR = 7.0, 95 %CI = 4.8–10.0) compared to fit participants that were of normal weight and fit participants with normal WC, respectively. No increased odds ratio was observed for fit participants that had increased BMI or WC. In conclusion, projected physical independence may be enhanced by a normal weight, a normal WC, or an increased physical fitness. Adiposity measures were not associated with physical independence, whereas fitness is independently related to physical independence. Independent of their weight and WC status, unfit older adults are at increased risk for losing physical independence.

• Dalene, Knut Eirik; Anderssen, Sigmund Alfred; Ekelund, Ulf; Thoren, Anne-Karine Halvorsen; Hansen, Bjørge Hermann & Kolle, Elin (2016). Permanent play facility provision is associated with children's time spent sedentary and in light physical activity during school hours: A cross-sectional study. Preventive Medicine Reports. 4, p. 429–434. doi: 10.1016/j.pmedr.2016.08.011. Full text in Research Archive Show summary

  Objective: To study the associations between: 1) number of permanent outdoor play facilities per pupil and 2) the size of the outdoor play area per pupil with sedentary time and physical activity (PA) during school hours in six-, nine-, and 15-year olds. We conducted a cross-sectional study of nationally representative samples of Norwegian six- (n = 1071), nine- (n = 1421) and 15-year-olds (n = 1106) in 2011 (the Physical Activity Among Norwegian Children Study). The participation rates were 56.4%, 73.1% and 57.8% for six-, nine- and 15-year olds, respectively. We assessed PA objectively for seven consecutive days using accelerometers, the size of a school's outdoor play area (SOPA) using an online map service and the permanent play facility (PPF) provision using a standardized form during school site visits. We successfully measured SOPA and PPF in 99 schools, from which 3040 participants provided valid accelerometer data. We used generalized least-squares random-effects models with robust variance estimation to assess associations. Our results indicate that better provision of permanent play facilities may reduce sedentary time and increase time spent in light PA among six-year-olds. Permanent play facility provision was not associated with sedentary time or PA among nine- and 15-year-olds. Associations found between outdoor play area size, physical activity and sedentary time were negligible. Future research should investigate what types of permanent play facilities may be associated with physical activity in both children and adolescents.

• Resaland, Geir Kåre; Aadland, Eivind; Moe, Vegard Fusche; Aadland, Katrine Nyvoll; Skrede, Turid & Stavnsbo, Mette [Show all 20 contributors for this article] (2016). Effects of physical activity on schoolchildren's academic performance: The Active Smarter Kids (ASK) cluster-randomized controlled trial. Preventive Medicine. ISSN 0091-7435. 91, p. 322–328. doi: 10.1016/j.ypmed.2016.09.005. Full text in Research Archive Show summary

  Objective: To investigate the effect of a seven-month, school-based cluster-randomized controlled trial on academic performance in 10-year-old children. Methods: In total, 1129 fifth-grade children from 57 elementary schools in Sogn og Fjordane County, Norway, were cluster-randomized by school either to the intervention group or to the control group. The children in the 28 intervention schools participated in a physical activity intervention between November 2014 and June 2015 consisting of three components: 1) 90 min/week of physically active educational lessons mainly carried out in the school playground; 2) 5 min/day of physical activity breaks during classroom lessons; 3) 10 min/day physical activity homework. Academic performance in numeracy, reading and English was measured using standardized Norwegian national tests. Physical activity was measured objectively by accelerometry. Results: We found no effect of the intervention on academic performance in primary analyses (standardized difference 0.01–0.06, p > 0.358). Subgroup analyses, however, revealed a favorable intervention effect for those who performed the poorest at baseline (lowest tertile) for numeracy (p = 0.005 for the subgroup ∗ group interaction), compared to controls (standardized difference 0.62, 95% CI 0.19–1.07). Conclusions: This large, rigorously conducted cluster RCT in 10-year-old children supports the notion that there is still inadequate evidence to conclude that increased physical activity in school enhances academic achievement in all children. Still, combining physical activity and learning seems a viable model to stimulate learning in those academically weakest schoolchildren.

• Kantomaa, Marko T.; Tikanmäki, Marjaana; Kankaanpää, Anna; Vääräsmäki, Marja; Sipola-Leppänen, Marika & Ekelund, Ulf [Show all 10 contributors for this article] (2016). Accelerometer-measured physical activity and sedentary time differ according to education level in young adults. PLOS ONE. 11:e0158902(7), p. 1–13. doi: 10.1371/journal.pone.0158902. Full text in Research Archive Show summary

  This study examined the association of education level with objectively measured physical activity and sedentary time in young adults. Data from the Finnish ESTER study (2009– 2011) (n = 538 was used to examine the association between educational attainment and different subcomponents of physical activity and sedentary time measured using hip-worn accelerometers (ActiGraph GT1M) for seven consecutive days. Overall physical activity, moderate-to-vigorous physical activity (MVPA), light-intensity physical activity and sedentary time were calculated separately for weekdays and weekend days. A latent profile analysis was conducted to identify the different profiles of sedentary time and the subcomponents of physical activity. The educational differences in accelerometer-measured physical activity and sedentary time varied according to the subcomponents of physical activity, and between weekdays and weekend days. A high education level was associated with high MVPA during weekdays and weekend days in both sexes, high sedentary time during weekdays in both sexes, and a low amount of light-intensity physical activity during weekdays in males and during weekdays and weekend days in females. The results indicate different challenges related to unhealthy behaviours in young adults with low and high education: low education is associated with a lack of MVPA, whereas high education is associated with a lack of light-intensity physical activity and high sedentary time especially during weekdays.

• Marques, Adilson; Ekelund, Ulf & Sardinha, Luis B. (2016). Associations between organized sports participation and objectively measured physical activity, sedentary time and weight status in youth. Journal of Science and Medicine in Sport. ISSN 1440-2440. 19(2), p. 154–157. doi: 10.1016/j.jsams.2015.02.007. Full text in Research Archive Show summary

  Objectives: The purpose of this study was to examine whether participation in organized sports is related to achieving physical activity recommendations, body mass index (BMI), objectively measured PA intensity and time spent sedentary. Design: Cross-sectional study. Methods: The sample comprised 973 children and adolescents (427 boys, 546 girls) aged 10-18 years (Mage=14.1±2.4). Organized sport was self-reported. Physical activity and time spent in moderate and vigorous intensity PA (MVPA) and sedentary time was assessed with accelerometers. Results: More boys (51.3%) than girls (28.3%) reported to be involved in organized sports participation (p<0.001). Those who were engaged in organized sports were more likely to achieve physical activity guidelines (OR=1.64, 95% CI: 1.14-2.35, p<0.01), spent more time in MPA (OR=1.01, 95% CI: 1.01-1.02, p<0.01), VPA (OR=1.09, 95% CI: 1.05-1.13, p<0.001), and MVPA (OR=1.01, 95% CI: 1.01-1.02, p<0.001) than those who did not participate in organized sports. No associations between organised sport participation and time spent sedentary or BMI was observed. Conclusions: Engagement in organized sports is related to higher levels of objectively measured MPA, VPA and achieving the recommended levels of MVPA in youth; however participation in sports appears unrelated to time spent sedentary and BMI. Our results suggest that promoting organised sport may increase physical activity of at least moderate intensity in young people.

• Loyen, Anne; Hecke, Linde Van; Verloigne, Maïté; Hendriksen, Ingrid; Lakerveld, Jeroen & Steene-Johannessen, Jostein [Show all 14 contributors for this article] (2016). Variation in population levels of physical activity in European adults according to cross-European studies: a systematic literature review within DEDIPAC. International Journal of Behavioral Nutrition and Physical Activity. 13:72, p. 1–18. doi: 10.1186/s12966-016-0398-2. Full text in Research Archive Show summary

  Background: Physical inactivity is a well-known public health risk that should be monitored at the population level. Physical activity levels are often surveyed across Europe. This systematic literature review aims to provide an overview of all existing cross-European studies that assess physical activity in European adults, describe the variation in population levels according to these studies, and discuss the impact of the assessment methods. Methods: Six literature databases (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey) were searched, supplemented with backward- and forward tracking and searching authors’ and experts’ literature databases. Articles were included if they reported on observational studies measuring total physical activity and/or physical activity in leisure time in the general population in two or more European countries. Each record was reviewed, extracted and assessed by two independent researchers and disagreements were resolved by a third researcher. The review protocol of this review is registered in the PROSPERO database under registration number CRD42014010334. Results: Of the 9,756 unique identified articles, twenty-five were included in this review, reporting on sixteen different studies, including 2 to 35 countries and 321 to 274,740 participants. All but two of the studies used questionnaires to assess physical activity, with the majority of studies using the IPAQ-short questionnaire. The remaining studies used accelerometers. The percentage of participants who either were or were not meeting the physical activity recommendations was the most commonly reported outcome variable, with the percentage of participants meeting the recommendations ranging from 7 % to 96 % across studies and countries. Conclusions: The included studies showed substantial variation in the assessment methods, reported outcome variables and, consequently, the presented physical activity levels. Because of this, absolute population levels of physical activity in European adults are currently unknown. However, when ranking countries, Ireland, Italy, Malta, Portugal, and Spain generally appear to be among the less active countries. Objective data of adults across Europe is currently limited. These findings highlight the need for standardisation of the measurement methods, as well as cross-European monitoring of physical activity levels.

• Sluijs, Esther M.F. van; Sharp, Stephen J.; Ambrosini, Gina L.; Cassidy, Aedin; Griffin, Simon J. & Ekelund, Ulf (2016). The independent prospective associations of activity intensity and dietary energy density with adiposity in young adolescents. British Journal of Nutrition. ISSN 0007-1145. 115(5), p. 921–929. doi: 10.1017/S0007114515005097. Full text in Research Archive Show summary

  There is limited evidence on the prospective association of time spent in activity intensity (sedentary (SED), moderate (MPA) or vigorous (VPA) physical activity) and dietary intake with adiposity indicators in young people. This study aimed to assess associations between (1) baseline objectively measured activity intensity, dietary energy density (DED) and 4-year change in adiposity and (2) 4-year change in activity intensity/DED and adiposity at follow-up. We conducted cohort analyses including 367 participants (10 years at baseline, 14 years at follow-up) with valid data for objectively measured activity (Actigraph), DED (4-d food diary), anthropometry (waist circumference (WC), %body fat (%BF), fat mass index (FMI), weight status) and covariates. Linear and logistic regression models were fit, including adjustment for DED and moderate-to-vigorous physical activity. Results showed that baseline DED was associated with change in WC (β for 1kJ/g difference: 0·71; 95% CI 0·26, 1·17), particularly in boys (1·26; 95% CI 0·41, 2·16 v. girls: 0·26; 95% CI −0·34, 0·87), but not with %BF, FMI or weight status. In contrast, baseline SED, MPA or VPA were not associated with any of the outcomes. Change in DED was negatively associated with FMI (β for 1kJ/g increase: −0·86; 95% CI −1·59, −0·12) and %BF (−0·86; 95% CI −1·25, −0·11) but not WC (−0·27; 95% CI −1·02, 0·48). Change in SED, MPA and VPA did not predict adiposity at follow-up. In conclusion, activity intensity was not prospectively associated with adiposity, whereas the directions of associations with DED were inconsistent. To inform public health efforts, future studies should continue to analyse longitudinal data to further understand the independent role of different energy-balance behaviours in changes in adiposity in early adolescence.

• Sherar, Lauren B.; Griffin, Tom P.; Ekelund, Ulf; Cooper, Ashley R.; Esliger, Dale W. & Sluijs, Esther M.F. van [Show all 19 contributors for this article] (2016). Association between maternal education and objectively measured physical activity and sedentary time in adolescents. Journal of Epidemiology and Community Health. ISSN 0143-005X. 70(6), p. 541–548. doi: 10.1136/jech-2015-205763. Full text in Research Archive Show summary

  Background: Investigating socioeconomic variation in physical activity (PA) and sedentary time is important as it may represent a pathway by which socioeconomic position (SEP) leads to ill health. Findings on the association between children's SEP and objectively assessed PA and/or sedentary time are mixed, and few studies have included international samples. Objective: Examine the associations between maternal education and adolescent's objectively assessed PA and sedentary time. Methods: This is an observational study of 12 770 adolescents (10–18 years) pooled from 10 studies from Europe, Australia, Brazil and the USA. Original PA data were collected between 1997 and 2009. The associations between maternal education and accelerometer variables were examined using robust multivariable regression, adjusted for a priori confounders (ie, body mass index, monitor wear time, season, age and sex) and regression coefficients combined across studies using random effects meta-analyses. Analyses were conducted in March 2014. Results: Adolescents of university educated mothers spent more time sedentary (9.5 min/day, p=0.005) and less time in light activity (10 min/day, p<0.001) compared with adolescents of high school educated mothers. Pooled analysis across two studies from Brazil and Portugal (analysed separately because of the different coding of maternal education) showed that children of higher educated mothers (tertiary vs primary/secondary) spent less time in moderate to vigorous PA (MVPA) (6.6 min/day, p=0.001) and in light PA (39.2 min/day: p<0.001), and more time sedentary (45.9 min/day, p<0.001). Conclusions: Across a number of international samples, adolescents of mothers with lower education may not be at a disadvantage in terms of overall objectively measured PA.

• Guo, Vivianyawei; Brage, Søren; Ekelund, Ulf; Griffin, Simon J. & Simmons, Rebecca K. (2016). Objectively measured sedentary time, physical activity and kidney function in people with recently diagnosed Type 2 diabetes: a prospective cohort analysis. Diabetic Medicine. ISSN 0742-3071. 33(9), p. 1222–1229. doi: 10.1111/dme.12886. Full text in Research Archive Show summary

  Aim: To assess the prospective association between objectively measured physical activity and kidney function over 4 years in people with Type 2 diabetes. Methods: Individuals (120 women and 206 men) participating in the ADDITION-Plus trial underwent assessment of sedentary time (SED-time), time spent in moderate-to-vigorous-intensity physical activity (MVPA) and total physical activity energy expenditure (PAEE) using a combined heart rate and movement sensor, and kidney function [estimated glomerular filtration rate (eGFR), serum creatinine and urine albumin-to-creatinine ratio (ACR)] at baseline and after 4 years of follow-up. Multivariate regression was used to quantify the association between change in SED-time, MVPA and PAEE and kidney measures at four-year follow-up, adjusting for change in current smoking status, waist circumference, HbA1c, systolic blood pressure, triglycerides and medication usage. Results: Over 4 years, there was a decline in eGFR values from 87.3 to 81.7 ml/min/1.73m2 (P < 0.001); the prevalence of reduced eGFR (eGFR < 60 ml/min/1.73m2) increased from 6.1 to 13.2% (P < 0.001). There were small increases in serum creatinine (median: 81–84 μmol/l, P < 0.001) and urine ACR (median: 0.9–1.0 mg/mmol, P = 0.005). Increases in SED-time were associated with increases in serum creatinine after adjustment for MVPA and cardiovascular risk factors (β = 0.013, 95% CI: 0.001, 0.03). Conversely, increases in PAEE were associated with reductions in serum creatinine (β = –0.001, 95% CI: –0.003, –0.0001). Conclusion: Reducing time spent sedentary and increasing overall physical activity may offer intervention opportunities to improve kidney function among individuals with diabetes. (Trial Registry no. ISRCTN 99175498)

• Matsuzaki, Mika; Sullivan, Ruth; Ekelund, Ulf; Krishna, KV Radha; Kulkarni, Bharati & Collier, Tim [Show all 9 contributors for this article] (2016). Development and evaluation of the Andhra Pradesh Children and Parent Study Physical Activity Questionnaire (APCAPS-PAQ): A cross-sectional study. BMC Public Health. 16:48, p. 1–9. doi: 10.1186/s12889-016-2706-9. Full text in Research Archive Show summary

  Background: There is limited availability of context-specific physical activity questionnaires in low and middle income countries. The aim of this study was to develop and examine the validity of a new Indian physical activity questionnaire, the Andhra Pradesh Children and Parent Study Physical Activity Questionnaire (APCAPS-PAQ). Methods: The current study was conducted with the cohort from the Hyderabad DXA Study (n = 2321), recruited in 2009-2010. Criterion validity (n = 245) was examined by comparing the APCAPS-PAQ to a combined heart rate and motion sensor worn for 8 days. Construct validity (n = 2321) was assessed with linear regression, comparing APCAPS-PAQ against BMI, percent body fat, and pulse rate. Results: The APCAPS-PAQ criterion validity was variable depending on the PA intensity groups (ρ = 0.26, 0.07, 0.39; к = 0.14, 0.04, 0.16 for sedentary, light, moderate/vigorous physical activity (MVPA) respectively). Sedentary and light intensity activities from the questionnaire were underestimated when compared to the criterion data while MVPA in APCAPS-PAQ was overestimated. Higher time spent in sedentary activity in APCAPS-PAQ was associated with higher BMI and percent body fat, suggesting construct validity. Conclusions: The APCAPS-PAQ validity is comparable to other physical activity questionnaires. This tool is able to assess sedentary behavior, moderate/vigorous activity and physical activity energy expenditure on a group level with reasonable validity. This new questionnaire may be used for ranking individuals according to their sedentary time and physical activity in southern India.

• Brooke, Hannah L.; Atkin, Andrew J.; Corder, Kirsten; Ekelund, Ulf & Sluijs, Esther M.F. van (2016). Changes in time-segment specific physical activity between ages 10 and 14 years: A longitudinal observational study. Journal of Science and Medicine in Sport. ISSN 1440-2440. 19(1), p. 29–34. doi: 10.1016/j.jsams.2014.10.003. Full text in Research Archive Show summary

  Objectives: Describe (1) time-segment specific changes in physical activity (PA) into adolescence, (2) differences in change in PA between specific time-segments (weekdays–weekends, in-school–out-of-school, out-of-school–weekends, lesson-time–lunch-time), and (3) associations of change in time-segment specific with overall PA. Design: Longitudinal observational study (4-year follow-up). Methods: Children from the SPEEDY study (n = 769, 42% boys) had PA measured by accelerometer for at least three days at ages 10.2 ± 0.3, 11.2 ± 0.3 and 14.3 ± 0.3 years. Changes in moderate-to-vigorous PA (ΔMVPA, minutes ≥2000 counts/minute [cpm]) and total PA (ΔTPA, average cpm) during weekdays, weekends, in-school, out-of-school, lesson-times and lunch-times, were tested using three level (age, individual, school) mixed-effects linear regression. Differences in ΔMVPA/ΔTPA between time-segments were tested using time-segment × age interaction terms. Associations of four-year time-segment specific ΔMVPA/ΔTPA with four-year overall ΔMVPA/ΔTPA were tested using two level (time-segment specific ΔMVPA/ΔTPA, school) mixed-effects linear regression. Results: MVPA and TPA declined in all time-segments, except lesson-time MVPA. Annual ΔMVPA and, for boys only, ΔTPA was greater on weekends than weekdays (beta ± SE for interaction term: boys, −3.53 ± 0.83 min, −29.64 ± 7.64 cpm; girls, −2.20 ± 0.64 min) and out-of-school (boys, −4.36 ± 0.79 min, −19.36 ± 8.46 cpm; girls, −2.44 ± 0.63 min). ΔMVPA and ΔTPA during lunch-time was greater than during lesson-time (boys, −0.96 ± 0.20 min, −36.43 ± 6.55 cpm; girls, −0.90 ± 0.13 min, −38.72 ± 4.40 cpm). ΔTPA was greater out-of-school than in-school (boys, −19.89 ± 6.71 cpm; girls, −18.46 ± 6.51 cpm). For all time-segments, four-year ΔMVPA/ΔTPA was positively associated with four-year overall ΔMVPA/ΔTPA (all p < 0.042), except for girl's in-school and lunch-time TPA. Conclusions: Interventions focused on PA maintenance could target all time-segments, but weekends and out-of-school may be particularly advantageous due to the relatively large declines observed.

• Verloigne, Maïté; Loyen, Anne; Hecke, Linde Van; Lakerveld, Jeroen; Hendriksen, Ingrid & Bourdheaudhuij, Ilse De [Show all 11 contributors for this article] (2016). Variation in population levels of sedentary time in European children and adolescents according to cross-European studies: A systematic literature review within DEDIPAC. International Journal of Behavioral Nutrition and Physical Activity. 13:69. doi: 10.1186/s12966-016-0395-5. Full text in Research Archive Show summary

  Background: A high amount of sedentary time has been proposed as a risk factor for various health outcomes in adults. While the evidence is less clear in children and adolescents, monitoring sedentary time is important to understand the prevalence rates and how this behaviour varies over time and by place. This systematic literature review aims to provide an overview of existing cross-European studies on sedentary time in children (0-12y) and adolescents (13-18y), to describe the variation in population levels of sedentary time, and to discuss the impact of assessment methods. Methods: Six literature databases were searched (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey), followed by backward- and forward tracking and searching authors’ and experts’ literature databases. Included articles were observational studies reporting on levels of sedentary time in the general population of children and/or adolescents in at least two European countries. Population levels were reported separately for children and adolescents. Data were reviewed, extracted and assessed by two researchers, with disagreements being resolved by a third researcher. The review protocol is published under registration number CRD42014013379 in the PROSPERO database. Results: Forty-two eligible articles were identified, most were cross-sectional (n = 38). The number of included European countries per article ranged from 2 to 36. Levels of sedentary time were observed to be higher in East-European countries compared to the rest of Europe. There was a large variation in assessment methods and reported outcome variables. The majority of articles used a child-specific questionnaire (60 %). Other methods included accelerometers, parental questionnaires or interviews and ecological momentary assessment tools. Television time was reported as outcome variable in 57 % of included articles (ranging from a mean value of 1 h to 2.7 h in children and 1.3 h to 4.4 h in adolescents), total sedentary time in 24 % (ranging from a mean value of 192 min to 552 min in children and from 268 min to 506 min in adolescents). Conclusion: A substantial number of published studies report on levels of sedentary time in children and adolescents across European countries, but there was a large variation in assessment methods. Questionnaires (child specific) were used most often, but they mostly measured specific screen-based activities and did not assess total sedentary time. There is a need for harmonisation and standardisation of objective and subjective methods to assess sedentary time in children and adolescents to enable comparison across countries.

• Loyen, Anne; Verloigne, Maite; Hecke, Linde Van; Hendriksen, Ingrid; Lakerveld, Jeroen & Steene-Johannessen, Jostein [Show all 13 contributors for this article] (2016). Variation in population levels of sedentary time in European adults according to cross-European studies: A systematic literature review within DEDIPAC. International Journal of Behavioral Nutrition and Physical Activity. 13:71. doi: 10.1186/s12966-016-0397-3. Full text in Research Archive Show summary

  Background: Sedentary behaviour is increasingly recognized as a public health risk that needs to be monitored at the population level. Across Europe, there is increasing interest in assessing population levels of sedentary time. This systematic literature review aims to provide an overview of all existing cross-European studies that measure sedentary time in adults, to describe the variation in population levels across these studies and to discuss the impact of assessment methods. Methods: Six literature databases (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey) were searched, supplemented with backward- and forward tracking and searching authors’ and experts’ literature databases. Articles were included if they reported on observational studies measuring any form of sedentary time in the general population in two or more European countries. Each record was reviewed, extracted and assessed by two independent researchers, and disagreements were resolved by a third researcher. The review protocol of this review is registered in the PROSPERO database under registration number CRD42014010335. Results: Of the 9,756 unique articles that were identified in the search, twelve articles were eligible for inclusion in this review, reporting on six individual studies and three Eurobarometer surveys. These studies represented 2 to 29 countries, and 321 to 65,790 participants. Eleven studies focused on total sedentary time, while one studied screen time. The majority of studies used questionnaires to assess sedentary time, while two studies used accelerometers. Total sedentary time was reported most frequently and varied from 150 (median) to 620 (mean) minutes per day across studies and countries. Conclusions: One third of European countries were not included in any of the studies. Objective measures of European adults are currently limited, and most studies used single-item self-reported questions without assessing sedentary behaviour types or domains. Findings varied substantially between studies, meaning that population levels of sedentary time in European adults are currently unknown. In general, people living in northern Europe countries appear to report more sedentary time than southern Europeans. The findings of this review highlight the need for standardisation of the measurement methods and the added value of cross-European surveillance of sedentary behaviour.

• Särnblad, Stefan; Magnuson, A.; Ekelund, Ulf & Åman, Jan (2016). Body fat measurement in adolescent girls with type 1 diabetes: a comparison of skinfold equations against dual-energy X-ray absorptiometry. Acta Paediatrica. ISSN 0803-5253. 105(10), p. 1211–1215. doi: 10.1111/apa.13366. Full text in Research Archive Show summary

  Aim: Skinfold measurement is an inexpensive and widely used technique for assessing the percentage of body fat (%BF). This study assessed the accuracy of prediction equations for %BF based on skinfold measurements compared to dual-energy X-ray absorptiometry (DXA) in girls with type 1 diabetes and healthy age-matched controls. Methods: We included 49 healthy girls and 44 girls with diabetes aged 12–19 years old, comparing the predicted %BF based on skinfold measurements and the %BF values obtained by a Lunar DPX-L scanner. The agreement between the methods was assessed using an Bland–Altman plot. Results: The skinfold measurements were significantly higher in girls with diabetes (p = 0.003) despite a nonsignificant difference in total %BF (p = 0.1). A significant association between bias and %BF was found for all tested equations in the Bland–Altman plots. Regression analysis showed that the association between skinfold measurements and %BF measured by DXA differed significantly (p = 0.039) between the girls with diabetes and the healthy controls. Conclusion: The accuracy of skinfold thickness equations for assessment of %BF in adolescent girls with diabetes is poor in comparison with DXA measurements as criterion. Our findings highlight the need for the development of new prediction equations for girls with type 1 diabetes.

• Sardinha, Luís B.; Santos, Diana A.; Silva, Analiza M.; Grøntved, Anders; Andersen, Lars Bo & Ekelund, Ulf (2016). A comparison between BMI, waist circumference, and waist-to-height ratio for identifying cardio-metabolic risk in children and adolescents. PLOS ONE. 11(2). doi: 10.1371/journal.pone.0149351. Full text in Research Archive Show summary

  Background: There is controversial evidence on the associations between anthropometric measures with clustering of cardiovascular disease risk factors in pediatric ages. We aimed to examine the associations between body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) with clustered cardiometabolic risk factors and to determine whether these anthropometric variables can be used to discriminate individuals with increased cardiometabolic risk (increased clustered triglycerides, HDL-cholesterol, systolic and diastolic blood pressure, and HOMA-IR). Methods: The study sample of 4255 (2191 girls and 2064 boys) participants (8–17 years) was derived from pooled cross-sectional data comprising five studies. Outcomes included a continuous cardiometabolic risk factor z-score [corresponding to the sum of z-scores for triglycerides, HDL-cholesterol, systolic and diastolic blood pressure (mean arterial pressure), and HOMA-IR] and children with ≥1.0 SD in this score were defined as being at risk for clustering cardiometabolic risk factors.. Exposure variables were BMI, WC, WHtR. Statistics included mixed-effect regression and ROC analysis. Results: All anthropometric variables were associated with clustered risk and the magnitudes of associations were similar for BMI, WC, and WHtR. Models including anthropometric variables were similar in discriminating children and adolescents at increased risk with areas under the ROC curve between 0.70 and 0.74. The sensitivity (boys: 80.5–86.4%; girls: 76.6–82.3%) was markedly higher than specificity (boys: 51.85–59.4%; girls: 60.8%). Conclusions: The magnitude of associations for BMI, WC, and WHtR are similar in relation to clustered cardiometabolic risk factors, and perform better at higher levels of BMI. However, the precision of these anthropometric variables to classify increased risk is low.

• Loyen, Anne; Clarke-Cornwell, Alexandra M.; Anderssen, Sigmund Alfred; Hagströmer, Maria; Sardinha, Luis B. & Sundquist, Kristina [Show all 15 contributors for this article] (2016). Sedentary time and physical activity surveillance through accelerometer pooling in four European countries. Sports Medicine. ISSN 0112-1642. 47(7), p. 1421–1435. doi: 10.1007/s40279-016-0658-y. Full text in Research Archive Show summary

  Objective: The objective of this study was to pool, harmonise and re-analyse national accelerometer data from adults in four European countries in order to describe population levels of sedentary time and physical inactivity. Methods: Five cross-sectional studies were included from England, Portugal, Norway and Sweden. ActiGraph accelerometer count data were centrally processed using the same algorithms. Multivariable logistic regression analyses were conducted to study the associations of sedentary time and physical inactivity with sex, age, weight status and educational level, in both the pooled sample and the separate study samples. Results: Data from 9509 participants were used. On average, participants were sedentary for 530 min/day, and accumulated 36 min/day of moderate to vigorous intensity physical activity. Twenty-three percent accumulated more than 10 h of sedentary time/day, and 72% did not meet the physical activity recommendations. Nine percent of all participants were classified as high sedentary and low active. Participants from Norway showed the highest levels of sedentary time, while participants from England were the least physically active. Age and weight status were positively associated with sedentary time and not meeting the physical activity recommendations. Men and higher-educated people were more likely to be highly sedentary, while women and lower-educated people were more likely to be inactive. Conclusions: We found high levels of sedentary time and physical inactivity in four European countries. Older people and obese people were most likely to display these behaviours and thus deserve special attention in interventions and policy planning. In order to monitor these behaviours, accelerometer-based cross-European surveillance is recommended.

• Marques, Adilson; Minderico, Cláudia S.; Martins, Sandra B.; Palmeira, António; Ekelund, Ulf & Sardinha, Luís B. (2016). Cross-sectional and prospective associations between moderate to vigorous physical activity and sedentary time with adiposity in children. International Journal of Obesity. ISSN 0307-0565. 40(1), p. 28–33. doi: 10.1038/ijo.2015.168. Full text in Research Archive Show summary

  BACKGROUND: Physical activity (PA) and sedentary time (SED) have both been suggested as potential risk factors for adiposity in children. However, there is paucity of data examining the temporal associations between these variables. OBJECTIVE: This study aimed to analyze the cross-sectional and prospective associations between PA, SED and body composition in children. METHODS: A total of 510 children (age at baseline 10.1 ± 0.8, age at follow-up 11.8 ± 0.9) from six Portuguese schools from the Oeiras Municipality participated in this study. PA and SED were measured by accelerometry and trunk fat mass (TFM) and body fat mass (BFM) were measured by dual energy X-ray absorptiometry. Fat mass index (FMI) was calculated as BFM divided by height squared. Several regression models adjusted for age, sex, maturity status, follow-up duration, baseline levels of the outcome variable and SED or moderate to vigorous PA (MVPA) were performed. RESULTS: MVPA (min per day) was cross-sectionally inversely associated with adiposity indexes (FMI, TFM and BFM). Adiposity indexes were inversely associated with time in MVPA. In prospective analyses, MVPA was associated with a lower levels of FMI (β = − 0.37, 95% confidence interval (CI): − 0.49 to − 0.26, Po0.001), TFM (β = − 0.20, 95% CI: − 0.29 to − 0.10, Po0.001) and BFM (β = − 0.37, 95% CI: − 0.49 to − 0.26, Po0.001). When the model was adjusted for age, sex, maturity status and for baseline levels of the outcome variables MVPA remained a significant predictor of lower adiposity indexes (FMI: β = − 0.09, 95% CI: − 0.16 to − 0.01, Po0.05; TFM: β = − 0.08, 95% CI: − 0.15 to − 0.01, Po0.05; BFM: β = − 0.07, 95% CI: − 0.15 to 0.00, Po0.05). Adiposity was not associated with MVPA when modeled as the exposure in prospective analyses. SED was not related with adiposity indexes, except for the relationship with FMI. CONCLUSIONS: In cross-sectional and prospective analyses, MVPA is associated with lower adiposity independent of covariates and SED. Results suggest that promoting MVPA is important for preventing gain in adiposity in healthy children.

• Silva, Inacio C.M. Da; Payne, Valerie L.C.; Hino, Adriano Akira; Varela, Andrea Ramirez; Reis, Rodrigo S. & Ekelund, Ulf [Show all 7 contributors for this article] (2016). Physical activity and safety from crime among adults: A systematic review. Journal of Physical Activity and Health. ISSN 1543-3080. 13(6), p. 663–670. doi: 10.1123/jpah.2015-0156. Full text in Research Archive Show summary

  Background: The aim of this study was to review the evidence to date on the association between physical activity and safety from crime. Methods: Articles with adult populations of 500+ participants investigating the association between physical activity and safety from crime were included. A methodological quality assessment was conducted using an adapted version of the Downs and Black checklist. Results: The literature search identified 15,864 articles. After assessment of titles, abstracts and full-texts, 89 articles were included. Most articles (84.3%) were derived from high-income countries and only 3 prospective articles were identified. Articles presented high methodological quality. In 38 articles (42.7%), at least one statistically significant association in the expected direction was reported (ie, safety from crime was positively associated with physical activity). Nine articles (10.1%) found an association in the unexpected direction and 42 (47.2%) did not find statistically significant associations. The results did not change when we analyzed articles separately by sex, age, type of measurement, or domains of physical activity evaluated. Conclusion: The current evidence, mostly based on cross-sectional studies, suggests a lack of association between physical activity and safety from crime. Prospective studies and natural experiments are needed, particularly in areas with wide crime variability.

• Hildebrand, Maria; Øglund, Guro Pauck; Wells, Jonathan C. & Ekelund, Ulf (2016). Prenatal, birth and early life predictors of sedentary behavior in young people: A systematic review. International Journal of Behavioral Nutrition and Physical Activity. 13:63. doi: 10.1186/s12966-016-0389-3. Full text in Research Archive Show summary

  Background: Our aim was to systematically summarize the evidence on whether prenatal, birth and early life factors up to 6 years of age predict sedentary behavior in young people (≤18 years). Methods: PRISMA guidelines were followed, and searches were conducted in PubMed, SPORTDiscus, EMBASE and Web of Science up to December 1, 2015. We included observational (non-intervention) and longitudinal studies, that reported data on the association between one or more of the potential predictors and objectively or subjectively measured sedentary behavior. Study quality was assessed using a formal checklist and data extraction was performed using standardized forms independently by two researchers. Results: More than 18,000 articles were screened, and 16 studies, examining 10 different predictors, were included. Study quality was variable (0.36-0.95). Two studies suggest that heritability and BMI in children aged 2–6 years were significant predictors of sedentary behavior later in life, while four and seven studies suggest no evidence for an association between gestational age, birth weight and sedentary behavior respectively. There was insufficient evidence whether other prenatal, birth and early life factors act as predictors of later sedentary behavior in young people. Conclusion: The results suggest that heritability and early childhood BMI may predict sedentary behavior in young people. However, small number of studies included and methodological limitations, including subjective and poorly validated sedentary behavior assessment, limits the conclusions.

• Collings, Paul J.; Westgate, Kate L.; Väistö, Juuso; Wijndaele, Katrien; Atkin, Andrew J. & Haapala, Eero A. [Show all 11 contributors for this article] (2016). Cross-Sectional Associations of Objectively-Measured Physical Activity and Sedentary Time with Body Composition and Cardiorespiratory Fitness in Mid-Childhood: The PANIC Study. Sports Medicine. ISSN 0112-1642. 47(4), p. 769–780. doi: 10.1007/s40279-016-0606-x. Full text in Research Archive Show summary

  Background: The minimum intensity of physical activity (PA) that is associated with favourable body composition and cardiorespiratory fitness (CRF) remains unknown. Objective: To investigate cross-sectional associations of PA and sedentary time (ST) with body composition and CRF in mid-childhood. Methods: PA, ST, body composition and CRF were measured in a population-based sample of 410 children (aged 7.6 ± 0.4 years). Combined heart-rate and movement sensing provided estimates of PA energy expenditure (PAEE, kJ/kg/day) and time (min/day) at multiple finegrained metabolic equivalent (MET) levels, which were also collapsed to ST and light PA (LPA), moderate PA (MPA) and vigorous PA (VPA). Fat mass index (FMI, kg/ m2), trunk fat mass index (TFMI, kg/m2) and fat-free mass index (FFMI, kg/m2.5) were derived from dual-energy X-ray absorptiometry. Maximal workload from a cycle ergometer test provided a measure of CRF (W/kg FFM). Linear regression and isotemporal substitution models were used to investigate associations. Results: The cumulative time above 2 METs (221 J/min/ kg) was inversely associated with FMI and TFMI in both sexes (p\0.001) whereas time spent above 3 METs was positively associated with CRF (p B 0.002); CRF increased and adiposity decreased dose-dependently with increasing MET levels. ST was positively associated with FMI and TFMI (p\0.001) but there were inverse associations between all PA categories (including LPA) and adiposity (p B 0.002); the magnitude of these associations depended on the activity being displaced in isotemporal substitution models but were consistently stronger for VPA. PAEE, MPA and to a greater extent VPA, were all positively related to CRF (p B 0.001). Conclusions: PA exceeding 2 METs is associated with lower adiposity in mid-childhood, whereas PA of 3 METs is required to benefit CRF. VPA was most beneficial for fitness and fatness, from a time-for-time perspective, but displacing any lower-for-higher intensity may be an important first-order public health strategy.

• Ekelund, Ulf & Hildebrand, Maria (2016). Measuring physical activity among youth. In Green, Kenneth Stanley & Smith, Andy (Ed.), Routledge Handbook of Youth Sport. Routledge. ISSN 9780415840033. p. 376–391. Full text in Research Archive Show summary

  The Routledge Handbook of Youth Sport is a comprehensive survey of the latest research into young people’s involvement in sport. Drawing on a wide diversity of disciplines, including sociology, psychology, policy studies, coaching, physical education and physiology, the book examines the importance of sport during a key transitional period of our lives, from the later teenage years into the early twenties, and therefore helps us develop a better understanding of the social construction of young people’s lives. The book covers youth sport in all its forms, from competitive game-contests and conventional sport to recreational activities, exercise and lifestyle sport, and at all levels, from elite competition to leisure time activities and school physical education. It explores youth sport across the world, in developing and developed countries, and touches on some of the most significant themes and issues in contemporary sport studies, including physical activity and health, lifelong participation, talent identification and development, and safeguarding and abuse. No other book brings together in one place such a breadth and depth of material on youth sport or the engagement of young people in physical activity. The Routledge Handbook of Youth Sport is therefore important reading for all advanced students, researchers, practitioners and policy-makers with an interest in youth sport, youth culture, sport studies or physical education

• Haapala, Eero A.; Väistö, Juuso; Lintu, Niina; Tompuri, Tuomo; Brage, Søren & Westgate, Kate [Show all 11 contributors for this article] (2016). Adiposity, physical activity and neuromuscular performance in children. Journal of Sports Sciences. ISSN 0264-0414. 34(18), p. 1699–1706. doi: 10.1080/02640414.2015.1134805. Full text in Research Archive Show summary

  We investigated the associations of body fat percentage (BF%), objectively assessed moderate-to-vigorous physical activity (MVPA) and different types of physical activity assessed by a questionnaire with neuromuscular performance. The participants were 404 children aged 6–8 years. BF% was assessed using dualenergy x-ray absorptiometry and physical activity by combined heart rate and movement sensing and a questionnaire. The results of 50-m shuttle run, 15-m sprint run, hand grip strength, standing long jump, situp, modified flamingo balance, box-and-block and sit-and-reach tests were used as measures of neuromuscular performance. Children who had a combination of higher BF% and lower levels of physical activity had the poorest performance in 50-m shuttle run, 15-m sprint run and standing long jump tests. Higher BF% was associated with slower 50-m shuttle run and 15-m sprint times, shorter distance jumped in standing long jump test, fewer sit-ups, more errors in balance test and less cubes moved in box-and-block test. Higher levels of physical activity and particularly MVPA assessed objectively by combined accelerometer and heart rate monitor were related to shorter 50-m shuttle run and 15-msprint times. In conclusion, higher BF% and lower levels of physical activity and particularly the combination of these two factors were associated with worse neuromuscular performance.

• Corder, Kirsten; Sharp, Stephen J.; Atkin, Andrew J.; Griffin, Simon J.; Jones, Andrew P. & Ekelund, Ulf [Show all 7 contributors for this article] (2015). Change in objectively measured physical activity during the transition to adolescence. British Journal of Sports Medicine. ISSN 0306-3674. 49(11), p. 730–736. doi: 10.1136/bjsports-2013-093190. Full text in Research Archive Show summary

  Background: Physical activity (PA) declines during adolescence but change in different PA intensities across population subgroups is rarely explored. We describe change in sedentary (SED) time, light (LPA), moderate (MPA) and vigorous PA (VPA) assessed at three time points over 4 years. Methods: Accelerometer-assessed PA (min) was obtained at baseline (N=2064), 1 and 4 years later among British children (baseline mean±SD 10.2±0.3-year-old; 42.5% male). Change in SED (<100 counts/min (cpm)), LPA (101–1999 cpm), MPA (2000–3999 cpm) and VPA (≥4000 cpm) was studied using three-level (age, individual and school) mixed-effects linear regression including participants with data at ≥2 time points (N=990). Differences in change by sex, home location and weight status were explored with interactions for SED, LPA and moderate and vigorous PA (MVPA). Results: SED increased by 10.6 (95% CI 9.1 to 12.2) min/day/year. MPA and VPA decreased by 1.4 (1.0 to 1.8) and 1.5 (1.1 to 1.8) min/day/year, respectively. VPA decreased more than MPA as a percentage of the baseline value. MVPA declined more steeply among boys (3.9 (3.0 to 4.8)) versus girls (2.0 (1.2 to 2.7) min/day/year) despite lower MVPA among girls at all ages; rural (4.4 (3.5 to 5.2)) versus urban individuals (1.3 (0.4 to 2.3) min/day/year) and on weekends (6.7 (5.2 to 8.1)) versus weekdays (2.8 (1.9 to 3.7) min/day/year). MVPA was consistently lower among overweight/obese individuals (−17.5 (−3.9 to −2.5) min/day/year). Conclusions: PA decreases and is replaced by SED during early adolescence in British youth. Results indicate the urgency of PA promotion among all adolescents but especially girls and in rural areas. Increasing VPA and targeting PA promotion during weekends appear important.

• Atkin, Andrew J.; Corder, Kirsten; Goodyer, Ian M.; Bamber, Diane J.; Ekelund, Ulf & Brage, Soren [Show all 8 contributors for this article] (2015). Perceived family functioning and friendship quality: Cross-sectional associations with physical activity and sedentary behaviours. International Journal of Behavioral Nutrition and Physical Activity. 12(23). doi: 10.1186/s12966-015-0180-x. Full text in Research Archive Show summary

  Background: This study examined the association of adolescent-reported family functioning and friendship quality with objectively-measured moderate to vigorous physical activity (MVPA), sedentary time, and self-reported sedentary behaviours. Methods: Data are from the ROOTS study. MVPA and sedentary time were assessed using combined movement and heart rate sensing. Time spent TV viewing, using the internet, playing video games, doing homework and reading for pleasure was self-reported. Data on objectively-measured and self-reported outcomes for weekdays was available for 738 (age 14.5y, 55.7% female) and 800 (56.3% female) participants, respectively. Adolescents perceived family functioning and friendship quality (Two subscales: ‘Good friendship qualities’, ‘Friendship difficulties’) was assessed by questionnaire. Analyses were conducted using multi-level linear or logistic regression. Results: Adolescents reporting better family functioning accumulated more MVPA on weekdays (beta; 95% confidence interval: 0.57; 0.17,0.98). Higher scores on the good friendship qualities subscale was associated with greater MVPA throughout the week (weekdays: 1.13; 0.62,1.65, weekend: 0.56; 0.09,1.02) and lower sedentary time on weekdays (−10.34; −17.03,-3.66). Boys from better functioning families were less likely to report playing video games at the weekend (OR; 95% confidence interval: 0.73; 0.57,0.93) or reading for pleasure (weekday: 0.73; 0.56,0.96 weekend: 0.75; 0.58,0.96). Boys who attained higher scores on the good friendship qualities scale were less likely to play video games at the weekend (0.61; 0.44,0.86) or report high homework on weekdays (0.54; 0.31,0.94). A higher score for good friendship qualities was associated with lower odds of girls playing video games during the week (0.76; 0.58,1.00) or reading for pleasure at the weekend (0.61; 0.42,0.88). Girls that reported fewer friendship difficulties had lower odds of high TV viewing (0.76; 0.62,0.93) or playing video games (0.71; 0.52,0.97) at the weekend, and lower odds of reading for pleasure (0.63; 0.49,0.81) or reporting high homework on weekdays (0.70; 0.52,0.95). Discussion: Family functioning and friendship quality exhibit a complex pattern of association with physical activity and sedentary behaviour that varies by sex and day of the week. Findings highlight the potential value of targeting interpersonal aspects of the family and friendships as an adjunct to behaviour change interventions.

• Andersen, Lars Bo; Lauersen, Jeppe Bo; Brønd, Jan Christian; Anderssen, Sigmund Alfred; Sardinha, Luís B. & Steene-Johannessen, Jostein [Show all 15 contributors for this article] (2015). A new approach to define and diagnose cardiometabolic disorder in children. Journal of Diabetes Research. ISSN 2314-6745. 2015. doi: 10.1155/2015/539835. Full text in Research Archive
• Harris, Tess; Kerry, Sally M.; Victor, Christina R.; Ekelund, Ulf; Woodcock, Alison & Iliffe, Steve [Show all 15 contributors for this article] (2015). A Primary Care Nurse-Delivered Walking Intervention in Older Adults: PACE (Pedometer Accelerometer Consultation Evaluation)-Lift Cluster Randomised Controlled Trial. PLoS Medicine. ISSN 1549-1277. 12(2). doi: 10.1371/journal.pmed.1001783. Full text in Research Archive
• Andersen, Eivind; Ekelund, Ulf & Anderssen, Sigmund Alfred (2015). Effects of Reducing Sedentary Time on Glucose Metabolism in Pakistani Immigrant Men. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 47(4), p. 775–781. doi: 10.1249/MSS.0000000000000460. Full text in Research Archive Show summary

  Purpose - To examine the association between changes in objectively measured overall physical activity (PA), with changes in fasting and postprandial plasma insulin, C-peptide and glucose concentrations, in type 2 diabetes prone Pakistani immigrant men living in Norway and to examine whether this association is explained by changes in moderate-and-vigorous PA (MVPA) or changes in sedentary time. Methods - The current study is a secondary cohort analysis on data collected from the Physical activity and minority health study, a randomised controlled trial aimed to increase the PA level, and not sedentary time per se, in a group of sedentary Pakistani immigrant men (n=150). For the present analyses the two groups were merged and a cohort analysis performed. Overall PA (counts per min) and its sub-components, sedentary time and MVPA were measured with accelerometry. Outcome variables were measured after a 2-hour standardised glucose tolerance test. Results –Change in overall PA was significantly associated with postprandial log transformed plasma insulin (β=-0.002, 95% CI -0.003 to 0.000, P=0.008), C-peptide (β=-2.7, 95% CI -4.9 to -0.5, P=0.01) and glucose concentration (β=-0.006, 95% CI -0.01 to -0.002, P=0.002). Change in sedentary time was significantly and beneficially associated with changes in postprandial log transformed plasma insulin (β=0.002, 95% CI 0.001 to 0.003, P=0.001), C-peptide (β=3.7, 95% CI 1.5 to 6.0, P=0.001) and glucose concentration (β=0.006, 95% CI 0.002 to 0.1, P=0.002) independent of changes in MVPA, waist circumference and other confounders. Conclusion – Increasing overall PA by reducing sedentary time appears as important as increasing time spent at MVPA in relation to postprandial plasma insulin and glucose levels in diabetes prone immigrant men.

• Silva, Analiza Mónica Onica; Santos, Diana Aguiar; Matias, Catarina Nunes; Judice, Pedro B.; Magalhães, João Paulo P. & Ekelund, Ulf [Show all 7 contributors for this article] (2015). Accuracy of a combined heart rate and motion sensor for assessing energy expenditure in free-living adults during a double-blind crossover caffeine trial using doubly labeled water as the reference method. European Journal of Clinical Nutrition. ISSN 0954-3007. 69(1), p. 20–27. doi: 10.1038/ejcn.2014.51. Full text in Research Archive Show summary

  Background/Objectives: A combined heart rate (HR) and motion sensor (Actiheart) has been proposed as an accurate method for assessing total energy expenditure (TEE) and physical activity energy expenditure (PAEE). However, the extent to which factors such as caffeine may affect the accuracy by which the estimated HR-related PAEE contribution will affect TEE and PAEE estimates is unknown. Therefore, we examined the validity of Actiheart in estimating TEE and PAEE in free-living adults under a caffeine trial compared with doubly labeled water (DLW) as reference criterion. Subjects/Methods: Using a double-blind crossover trial (Clinicaltrials.gov ID: #NCT01477294) with two conditions (4-day each with a 3-day-washout period), randomly ordered as caffeine (5 mg/kg per day) and placebo (malt-dextrine) intake, TEE was measured by DLW in 17 physically active men (20–38 years) who were non-caffeine users. In each condition, resting energy expenditure (REE) was assessed by indirect calorimetry and PAEE was calculated as (TEE−(REE+0.1 TEE)). Simultaneously, PAEE and TEE were estimated by Actiheart using an individual calibration (ACC+HRstep). Results: Under caffeine, ACC+HRstep explained 76 and 64% of TEE and PAEE from DLW, respectively; corresponding results for the placebo condition were 82 and 66%. No mean bias was found between ACC+HRstep and DLW for TEE (caffeine:-468 kJ per day; placebo:-407 kJ per day), although PAEE was slightly underestimated (caffeine:-856 kJ per day; placebo:-1147 kJ per day). Similar limits of agreement were observed in both conditions ranging from −2066 to 3002 and from −3488 to 1776 kJ per day for TEE and PAEE, respectively. Conclusions: Regardless of caffeine intake, the combined HR and motion sensor is valid for estimating free-living energy expenditure in a group of healthy men but is less accurate for an individual assessment.

• Sardinha, Luis B.; Ekelund, Ulf; Santos, Leonardo dos; Cyrino, Edilson S.; Silva, Analiza M. & Santos, Diana (2015). Breaking-up sedentary time is associated with impairment in activities of daily living. Experimental Gerontology. ISSN 0531-5565. 72, p. 57–62. doi: 10.1016/j.exger.2015.09.011. Full text in Research Archive Show summary

  Identifying modifiable behaviors associated with prevention of activities of daily living (ADL) impairments is vital to implement preventive strategies for independent living in elderly. We aimed to examine the associations between objectively measured breaks in sedentary time with ADL impairments and physical independence. Cross-sectional assessments were carried out in 371 participants (131 male) aged 65–103 years from the Portuguese surveillance system of physical activity. Physical activity (PA) and sedentary time (ST) were assessed with accelerometry, and ADL impairments and physical independence with the self-reported 12-item composite physical function scale. Using ROC analyses a cut-off of 7 hourly breaks in sedentary time was identified which maximized the sensitivity and specificity in diagnosing physical dependence. Logistic regression analysis demonstrated that, independently of moderate-to-vigorous PA (MVPA), participants performing ≤ 7 hourly breaks in sedentary time had 2 to 7 fold increased odds for impairment in 10 of the 12 ADL. When stratifying ADL into basic, instrumental and advanced ADL we verified that less than 7 hourly breaks in sedentary time was associated with a 2 to 5 fold increased odds for impairments and physical dependence, independent of MVPA. No associations were observed between meeting PA guidelines and basic, instrumental, and advanced ADL impairment although time in MVPA was lower in participants showing impairments. In conclusion, the frequency of breaks in sedentary time in older ages is independently associated with lower risk for ADL impairments and physical dependence. Our findings support interventions to encourage older adults to increase overall PA by interrupting sedentary time.

• Ekelund, Ulf; Ward, Heather A.; Norat, Teresa; Luan, Jian'an; May, Anne M. & Weiderpass, Elisabete [Show all 48 contributors for this article] (2015). Physical activity and all-cause mortality across levels of overall and abdominal adiposity in European men and women: The European prospective investigation into cancer and nutrition study (EPIC). American Journal of Clinical Nutrition. ISSN 0002-9165. 101(3), p. 613–621. doi: 10.3945/ajcn.114.100065. Full text in Research Archive Show summary

  Background: The higher risk of death resulting from excess adiposity may be attenuated by physical activity (PA). However, the theoretical number of deaths reduced by eliminating physical inactivity compared with overall and abdominal obesity remains unclear. Objective: We examined whether overall and abdominal adiposity modified the association between PA and all-cause mortality and estimated the population attributable fraction (PAF) and the years of life gained for these exposures. Design: This was a cohort study in 334,161 European men and women. The mean follow-up time was 12.4 y, corresponding to 4,154,915 person-years. Height, weight, and waist circumference (WC) were measured in the clinic. PA was assessed with a validated self-report instrument. The combined associations between PA, BMI, and WC with mortality were examined with Cox proportional hazards models, stratified by center and age group, and adjusted for sex, education, smoking, and alcohol intake. Center-specific PAF associated with inactivity, body mass index (BMI; in kg/m2) (>30), and WC (≥102 cm for men, ≥88 cm for women) were calculated and combined in random-effects meta-analysis. Life-tables analyses were used to estimate gains in life expectancy for the exposures. Results: Significant interactions (PA × BMI and PA × WC) were observed, so HRs were estimated within BMI and WC strata. The hazards of all-cause mortality were reduced by 16–30% in moderately inactive individuals compared with those categorized as inactive in different strata of BMI and WC. Avoiding all inactivity would theoretically reduce all-cause mortality by 7.35% (95% CI: 5.88%, 8.83%). Corresponding estimates for avoiding obesity (BMI >30) were 3.66% (95% CI: 2.30%, 5.01%). The estimates for avoiding high WC were similar to those for physical inactivity. Conclusion: The greatest reductions in mortality risk were observed between the 2 lowest activity groups across levels of general and abdominal adiposity, which suggests that efforts to encourage even small increases in activity in inactive individuals may be beneficial to public health.

• Hildebrand, Maria; Kolle, Elin; Hansen, Bjørge Hermann; Collings, Paul J.; Wijndaele, Katrien & Kordas, Katarzyna [Show all 14 contributors for this article] (2015). Association between birth weight and objectively measured sedentary time is mediated by central adiposity: data in 10,793 youth from the International Children’s Accelerometry Database. American Journal of Clinical Nutrition. ISSN 0002-9165. 101(5), p. 983–990. doi: 10.3945/ajcn.114.103648. Full text in Research Archive Show summary

  Background: Birth weight is an early correlate of disease later in life, and animal studies suggest that low birth weight is associated with reduced activity and increased sedentary time. Whether birth weight predicts later sedentary time in humans is uncertain. Objectives: We examined the relation between birth weight and sedentary time in youth and examined whether this association was mediated by central adiposity. Design: We used pooled cross-sectional data from 8 observational studies conducted between 1997 and 2007 that consisted of 10,793 youth (boys: 47%) aged 6–18 y from the International Children’s Accelerometry Database. Birth weight was measured in hospitals or maternally reported, sedentary time was assessed by using accelerometry (<100 counts/min), and abdominal adiposity (waist circumference) was measured according to WHO procedures. A mediation analysis with bootstrapping was used to analyze data. Results: The mean (±SD) time spent sedentary was 370 ± 91 min/d. Birth weight was positively associated with sedentary time (B = 4.04, P = 0.006) and waist circumference (B = 1.59, P < 0.001), whereas waist circumference was positively associated with sedentary time (B = 0.82, P < 0.001). Results of the mediation analysis showed a significant indirect effect of birth weight on sedentary time through waist circumference (B: 1.30; 95% bias-corrected CI: 0.94, 1.72), and when waist circumference was controlled for, the effect of birth weight on sedentary time was attenuated by 32% (B = 2.74, P = 0.06). Conclusion: The association between birth weight and sedentary time appears partially mediated by central adiposity, suggesting that both birth weight and abdominal adiposity may be correlates of sedentary time in youth.

• Collings, Paul J.; Wijndaele, Katrien; Corder, Kirsten; Westgate, Kate; Ridgway, Charlotte L. & Sharp, Stephen J. [Show all 10 contributors for this article] (2015). Magnitude and determinants of change in objectively-measured physical activity, sedentary time and sleep duration from ages 15 to 17.5y in UK adolescents: the ROOTS study. International Journal of Behavioral Nutrition and Physical Activity. 12:61, p. 1–10. doi: 10.1186/s12966-015-0222-4. Full text in Research Archive Show summary

  Background Self-reported physical activity (PA) and sleep duration (SLP) change markedly throughout adolescence. We sought to quantify changes in objectively-measured PA, sedentary time (ST) and SLP through adolescence, and to investigate baseline body composition and baseline activity levels as determinants of change. Methods Individually calibrated combined heart rate and movement sensing was used to estimate PA energy expenditure (PAEE), SLP, daily ST and time in light (LPA), moderate (MPA), vigorous (VPA), and moderate-to-vigorous physical activity (MVPA) in 144 adolescents (50 % boys) of mean age 15.1(±0.3)y at baseline and 17.5(±0.3)y at follow-up. Changes in PA (ΔPA), ST (ΔST) and SLP (ΔSLP) were calculated as follow-up minus baseline values. Waist circumference (WC) was measured at baseline and follow-up, as was fat mass index (FMI) and fat-free mass index (FFMI) by a pooled estimation method including bio-impedance. Comparison of baseline and follow-up activity was made by mixed-model ANOVA. Linear regression adjusted for baseline demographics, total and weekend hours of monitor wear time and the seasons of activity measurements, was used to investigate baseline body composition as determinants of ΔPA, ΔST and ΔSLP. A further model adjusted for baseline of the outcome assessed baseline activity as a predictor of behaviour change, and investigated associations for baseline body composition independent of the baseline level of the outcome. Results From baseline to follow-up levels of MPA and VPA declined (p ≤ 0.039). The annual decline in MVPA was equivalent to -4.5 and -3.0 min/d in boys and girls, respectively. Baseline FMI, FFMI and WC were positively associated with ΔLPA and negatively associated with ΔST in boys when adjusted for baseline of the outcome (p ≤ 0.037 for all). SLP increased from baseline to follow-up (p = 0.004) but ΔSLP was not associated with baseline body composition (p ≥ 0.13). For all variables, higher baseline levels were associated with greater declines over time (p ≤ 0.003). Conclusions Levels of higher-intensity PA decline from mid-to-late adolescence, whereas the duration of sleep increases. Changes in LPA and ST may be associated with baseline body composition, but the baseline level of the outcome is consistently the strongest predictor of changes in adolescent activity.

• Solbraa, Ane; Ekelund, Ulf; Holme, Ingar Morten K; Graff-Iversen, Sidsel; Steene-Johannessen, Jostein & Aadland, Eivind [Show all 7 contributors for this article] (2015). Long-term correlates of objectively measured physical activity and sedentary time in norwegian men and women. Journal of Physical Activity and Health. ISSN 1543-3080. 12(11), p. 1500–1507. doi: 10.1123/jpah.2014-0390. Full text in Research Archive Show summary

  Background: Sex, age, body mass index (BMI), perceived health and health behavior are correlates known to affect physical activity and sedentary time. However, studies have often been cross-sectional, and less is known about long-term correlates. Thus, the aims were to investigate 1) the associations between a set of characteristics (demographic, biological, psychological and behavioral) and objectively measured physical activity and sedentary time at 13 year follow-up, and 2) the association between changes in these characteristics over time and physical activity and sedentary time. Methods: Baseline characteristics were collected in 40-year-olds in 1996, and follow-up data on objectively measured physical activity and sedentary time were obtained in 2009 (n=240). Data were analyzed by multiple linear regressions. Results: Self-reported physical activity (p<0.001) and improved perceived health (p=0.046) were positively associated with moderate-to-vigorous physical activity (MVPA) whereas BMI (p=0.034) and increased BMI (p=0.014) were negatively associated with MVPA at follow-up. Women spent less time being sedentary than men (p=0.019). Education (p<0.001) was positively associated and improved perceived health (p=0.010) was negatively associated with sedentary time at follow-up. Conclusions: MVPA and sedentary time at follow-up were associated with behavioral, biological and demographic correlates. However, the nature of our analyses prevents us from inferring causality.

• Lamb, Maxine J.E.; Westgate, Kate; Brage, Søren; Ekelund, Ulf; Long, Gráinne H. & Griffin, Simon J. [Show all 8 contributors for this article] (2015). Prospective associations between sedentary time, physical activity, fitness and cardiometabolic risk factors in people with type 2 diabetes. Diabetologia. ISSN 0012-186X. 59(1), p. 110–120. doi: 10.1007/s00125-015-3756-8. Full text in Research Archive
• Bowen, Liza; Taylor, Amy E.; Sullivan, Ruth; Ebrahim, Shah; Kinra, Sanjay & Krishna, K.V. Radha [Show all 11 contributors for this article] (2015). Associations between diet, physical activity and body fat distribution: a cross sectional study in an Indian population. BMC Public Health. 15(281). doi: 10.1186/s12889-015-1550-7. Full text in Research Archive Show summary

  Background: Obesity is a growing health problem in India and worldwide, due to changes in lifestyle. This study aimed to explore the independent associations between dietary and physical activity exposure variables and total body fat and distribution in an Indian setting. Methods: Individuals who had participated in the Indian Migration Study (IMS) or the Andhra Pradesh Children And Parents' Study (APCAPS), were invited to participate in the Hyderabad DXA Study. Total and abdominal body fat of study participants was measured using DXA scans. Diet and physical activity (PA) levels were measured using questionnaires. Results: Data on 2208 participants was available for analysis; mean age was 49 yrs in IMS, 21 yrs in APCAPS. Total energy intake was positively associated with total body fat in the APCAPS sample: a 100 kcal higher energy intake was associated with 45 g higher body fat (95% CI 22, 68). In the IMS sample no association was found with total energy intake, but there was a positive association with percent protein intake (1% higher proportion of energy from protein associated with 509 g (95% CI 138,880) higher total body fat). Broadly the same pattern of associations was found with proportion of fat in the abdominal region as the outcome. PA was inversely associated with total body fat in both populations (in APCAPS, one MET-hour higher activity was associated with 46 g (95% CI 12, 81) less body fat; in the IMS it was associated with 145 g less body fat (95% CI 73, 218)). An inverse association was observed between PA and percentage abdominal fat in the IMS but no association was seen in the APCAPS population. Conclusions: In this Indian population, there was an inverse association between PA and body fat. Associations between body fat and dietary variables differed between the younger APCAPS population and older IMS population. Further longitudinal research is needed to elucidate causality and directions of these associations across the life course.

• Collings, Paul J.; Wijndaele, Katrien; Corder, Kirsten; Westgate, Kate; Ridgway, Charlotte L. & Sharp, Stephen J. [Show all 11 contributors for this article] (2015). Prospective associations between sedentary time, sleep duration and adiposity in adolescents. Sleep Medicine. ISSN 1389-9457. 16(6), p. 717–722. doi: 10.1016/j.sleep.2015.02.532. Full text in Research Archive Show summary

  Objective: The objective of this study was to investigate whether objectively measured sedentary time and sleep duration are associated with changes in adiposity from mid- to late adolescence. Methods: Students (n = 504, 42% boys) were recruited from schools in Cambridgeshire, UK. At baseline (mean age 15.0 ± 0.3 years), sedentary time was objectively measured by ≥3 days of combined heart rate and movement sensing. Concurrently, sleep duration was measured by combined sensing in conjunction with self-reported bed times. Fat mass index (FMI; kg/m2) was estimated at baseline and follow-up (17.5 ± 0.3 years) by anthropometry and bioelectrical impedance. FMI change (ΔFMI) was calculated by subtracting the baseline from follow-up values. Linear regression models adjusted for basic demographics, moderate-to-vigorous physical activity (MVPA), and depressive symptoms were used to investigate associations of sedentary time and sleep duration (mutually adjusted for one another) with ΔFMI. Results: FMI increased by 0.5 and 0.6 kg/m2 in boys and girls, respectively, but there was no association between sedentary time and ΔFMI in either gender (p ≥ 0.087), and no association between sleep duration and ΔFMI in girls (p ≥ 0.61). In boys, each additional hour of baseline sleep significantly reduced the ΔFMI by 0.13 kg/m2 (p = 0.049), but there was little evidence for this association after adjusting for MVPA and depressive symptoms (p = 0.15). Conclusions: Sedentary time may not determine changes in adiposity from mid- to late adolescence, nor may sleep duration in girls. However, sleep length may be inversely associated with adiposity gain in boys, depending on whether the relationship is confounded or mediated by MVPA and depression.

• Reichert, Felipe F.; Wells, Jonathan C.; Ekelund, Ulf; Menezes, Ana Maria B; Victora, Cesar G. & Hallal, Pedro C. (2015). Prospective Associations Between Physical Activity Level and Body Composition in Adolescence: 1993 Pelotas (Brazil) Birth Cohort. Journal of Physical Activity and Health. ISSN 1543-3080. 12(6), p. 834–839. doi: 10.1123/jpah.2013-0509. Full text in Research Archive Show summary

  Background: Physical activity may influence both fat and lean body mass. This study investigated the association between physical activity in children between the ages of 11 and 13 years and both fat and lean mass. Methods: A subsample of the 1993 Pelotas (Brazil) Birth Cohort was visited in 2004–2005 and 2006–2007. Physical activity was estimated through standardized questionnaires. Body composition (ie, fat and lean mass) was measured using deuterium dilution. Those with moderate-to-vigorous activity greater than 420 min/wk were classified as active, and physical activity trajectory was defined as being above or below the cutoff at each visit. Results: Four hundred eighty-eight adolescents (51.8% boys) were evaluated. The mean difference in fat mass in boys and girls who reported ≥ 420 min/wk of physical activity in both visits compared with those who were consistently inactive was –4.8 kg (P ≤ .001). There was an inverse association between physical activity and fat mass among boys in both crude and confounder-adjusted analyses, whereas for girls, the association was evident only in the crude analysis. There was no significant association between physical activity and lean mass. Conclusion: Physical activity may contribute to tackling the growing epidemic of adolescent obesity in low- and middle-income countries.

• Goharian, TS; Andersen, Lars Bo; Franks, PW; Wareham, NJ; Brage, S & Veidebaum, T [Show all 10 contributors for this article] (2015). Examining the causal association of fasting glucose with blood pressure in healthy children and adolescents: a Mendelian randomization study employing common genetic variants of fasting glucose. Journal of Human Hypertension. ISSN 0950-9240. 29, p. 179–184. doi: 10.1038/jhh.2014.63. Full text in Research Archive
• Adab, Peymane; Pallan, Miranda J.; Lancashire, Emma R.; Hemming, Karla; Frew, Emma & Griffin, Tania [Show all 18 contributors for this article] (2015). A cluster-randomised controlled trial to assess the effectiveness and cost-effectiveness of a childhood obesity prevention programme delivered through schools, targeting 6-7 year old children: The WAVES study protocol Disease epidemiology - Chronic. BMC Public Health. 15:488. doi: 10.1186/s12889-015-1800-8. Full text in Research Archive
• Assah, Felix; Mbanya, Jean-Claude; Ekelund, Ulf; Wareham, Nicholas & Brage, Søren (2015). J Epidemiol Community Health 2015;69:700-707 doi:10.1136/jech-2014-205154 Other topics Patterns and correlates of objectively measured free-living physical activity in adults in rural and urban Cameroon. Journal of Epidemiology and Community Health. ISSN 0143-005X. 69(7), p. 700–707. doi: 10.1136/jech-2014-205154. Full text in Research Archive
• Wijndaele, Katrien; Westgate, Kate; Stephens, Samantha K.; Blair, Steven N.; Bull, Fiona C. & Chastin, Sebastien F.M. [Show all 19 contributors for this article] (2015). Utilization and Harmonization of Adult Accelerometry Data: Review and Expert Consensus. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 47(10), p. 2129–2139. doi: 10.1249/MSS.0000000000000661. Full text in Research Archive Show summary

  Purpose: This study aimed to describe the scope of accelerometry data collected internationally in adults and to obtain a consensus from measurement experts regarding the optimal strategies to harmonize international accelerometry data. Methods: In March 2014, a comprehensive review was undertaken to identify studies that collected accelerometry data in adults (sample size, n >= 400). In addition, 20 physical activity experts were invited to participate in a two-phase Delphi process to obtain consensus on the following: unique research opportunities available with such data, additional data required to address these opportunities, strategies for enabling comparisons between studies/countries, requirements for implementing/progressing such strategies, and value of a global repository of accelerometry data. Results: The review identified accelerometry data from more than 275,000 adults from 76 studies across 36 countries. Consensus was achieved after two rounds of the Delphi process; 18 experts participated in one or both rounds. The key opportunities highlighted were the ability for cross-country/cross-population comparisons and the analytic options available with the larger heterogeneity and greater statistical power. Basic sociodemographic and anthropometric data were considered a prerequisite for this. Disclosure of monitor specifications and protocols for data collection and processing were deemed essential to enable comparison and data harmonization. There was strong consensus that standardization of data collection, processing, and analytical procedures was needed. To implement these strategies, communication and consensus among researchers, development of an online infrastructure, and methodological comparison work were required. There was consensus that a global accelerometry data repository would be beneficial and worthwhile. Conclusions: This foundational resource can lead to implementation of key priority areas and identification of future directions in physical activity epidemiology, population monitoring, and burden of disease estimates.

• Clarke, Joanne L; Griffin, Tania L; Lancashire, Emma R.; Adab, Peymane; Parry, Jayne & Pallan, Miranda J. [Show all 19 contributors for this article] (2015). Parent and child perceptions of school-based obesity prevention in England: a qualitative study. BMC Public Health. 15. doi: 10.1186/s12889-015-2567-7. Full text in Research Archive Show summary

  Background: Schools are key settings for childhood obesity prevention, and the location for many intervention studies. This qualitative study aims to explore parent and child experiences of the WAVES study obesity prevention intervention, in order to gain understanding of the mechanisms by which the intervention results in behaviour change, and provide context to support interpretation of the main trial results. Methods: Focus groups were held with 30 parents and 62 children (aged 6-7 years) from primary schools in the West Midlands, UK. Data analysis (conducted using NVivo 10) was guided by the Framework Approach. Results: Three over-arching themes were identified: ‘Impact’, ‘Sustainability’ and ‘Responsibilities’, under which sub-themes were determined. Participants were supportive of the school-based intervention. Parental involvement and the influential role of the teacher were seen as key ingredients for success in promoting consistent messages and empowering some parents to make positive behavioural changes at home. Parents recognised that whilst they held the primary responsibility for obesity prevention in their children, they faced a number of barriers to healthier lifestyles, and agreed that schools have an important role to play. Conclusions: This study enabled us to better understand aspects of the WAVES study intervention programme that have the potential to initiate positive behaviour changes in families, and indicated that a combination of pathways influenced such changes. Pathways included: increasing capability through improving knowledge and skills of children and parents; increasing motivation through parental empowerment and role modelling; and the direct provision of opportunities to lead healthier lifestyles. Strategies to sustain behaviour changes, and the school role in supporting these, are important considerations.

• Ahmad, Shaleen; Harris, Tess; Limb, Elizabeth; Kerry, Sally; Victor, Christina & Ekelund, Ulf [Show all 11 contributors for this article] (2015). Evaluation of reliability and validity of the General Practice Physical Activity Questionnaire (GPPAQ) in 60-74 year old primary care patients Service organization, utilization, and delivery of care. BMC Family Practice. 16:113. doi: 10.1186/s12875-015-0324-8. Full text in Research Archive Show summary

  Background: GPPAQ (General Practice Physical Activity Questionnaire) is a self-assessment physical activity questionnaire widely used in primary care. Reliability and validity data in older people are lacking. The study aims were: to assess GPPAQ’s reliability and validity in 60–74 year olds from the PACE-Lift (Pedometer Accelerometer Consultation Evaluation-Lift) physical activity trial; and to assess whether adding brisk walking to the GPPAQ score improves its validity when assessing if physical activity guidelines are being met. Method: Physical activity was assessed objectively by accelerometry and by self-report GPPAQ over one week periods at baseline, and three and twelve months later, in 60–74 year old participants from three United Kingdom general practices enrolled in PACE-Lift. Reliability: GPPAQ scores in controls (n = 148) were compared for repeatability at baseline, 3 and 12 months. Validity: we compared the GPPAQ “active” rating (those not requiring physical activity advice) with those achieving physical activity guidelines using accelerometry, in all baseline subjects (n = 298). Using accelerometry as an objective comparator, GPPAQ sensitivity and specificity were calculated and repeated after adding brisk walking into the GPPAQ score (GPPAQ-WALK). Results: For reliability, GPPAQ showed 56 % (70/126) and 67 % (87/129) of controls scored the same at 3 and 12 months respectively, as they scored at baseline. At baseline 24 % (69/289) achieved physical activity guidelines according to accelerometry, whilst 16 % (47/289) were classified as GPPAQ “active”. GPPAQ had 19 % (13/69) sensitivity and 85 % (186/220) specificity. GPPAQ-WALK had 39 % (27/69) sensitivity and 70 % (155/220) specificity. Conclusions: GPPAQ has reasonable reliability but results from this study measuring validity in older adults indicates poor agreement with objective accelerometry for accurately identifying physical activity levels. Including brisk walking in GPPAQ increased sensitivity, but reduced specificity and did not improve overall screening performance. GPPAQ’s use in National Health Service health checks in primary care in this age group cannot therefore be supported by this validity study comparing to accelerometry.

• Øglund, Guro Pauck; Hildebrand, Maria & Ekelund, Ulf (2015). Are birth weight, early growth, and motor development determinants of physical activity in children and youth? A systematic review and meta-analysis. Pediatric Exercise Science. ISSN 0899-8493. 27(4), p. 441–453. doi: 10.1123/pes.2015-0041. Full text in Research Archive Show summary

  The purpose of this systematic review was to explore whether birth weight, early growth and motor development act as determinants of physical activity in children and youth. Methods: We performed a systematic literature search on the possible early life determinants. A meta-analysis was performed on the association between birthweight and objectively measured physical activity. Results: We identified 9 studies examining birth weight, in which none of the studies with objectively measured physical activity observed an association between birth weight and physical activity. The meta-analysis confirmed this result (b=-3.08, 95% CI -10.20, 4.04). The 3 studies examining early growth and physical activity in youth differ in methodology and the results are inconsistent. Two studies suggest an association between earlier motor development and physical activity and sport participation in youth. This was not confirmed in a third study. Conclusion: Our meta-analysis suggests that birth weight is not an important determinant of physical activity in youth. Available data does not allow firm conclusions whether early growth and motor development act as determinants of physical activity in youth.

• Marques, Adilson; Santos, Rute; Ekelund, Ulf & Sardinha, Luis B. (2015). Association between Physical Activity, Sedentary Time and Healthy Fitness in Youth. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 47(3), p. 575–580. doi: 10.1249/MSS.0000000000000426. Full text in Research Archive
• Esteban-Cornejo, Irene; Hallal, Pedro C.; Mielke, Grégory; Menezes, Ana Maria B; Goncalves, Helen & Wehrmeister, Fernando [Show all 8 contributors for this article] (2015). Physical Activity throughout Adolescence and Cognitive Performance at 18 Years of Age. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 47(12), p. 2552–2557. doi: 10.1249/MSS.0000000000000706. Full text in Research Archive Show summary

  Purpose: This study aimed to examine the prospective associations of physical activity at 11, 15, and 18 yr of age with cognitive performance in young adulthood in a large birth cohort study from Brazil. Methods: Participants were part of a large birth cohort study in Pelotas, Brazil (n = 3235 participants). Physical activity was self-reported at 11, 15, and 18 yr and was also objectively measured at 18 yr. Cognitive performance was assessed using an adapted Brazilian version of the short form of the Wechsler Adult Intelligence Scale at 18 yr. Results: At 11 yr, participants in the middle tertile of self-reported physical activity presented a significantly higher cognitive performance score as compared with the lowest tertile. Physical activity at 15 yr of age was unrelated to cognitive performance at 18 yr. Self-reported physical activity was cross-sectionally positively associated with cognitive performance at 18 yr (P < 0.001). Data from objectively measured physical activity at 18 yr showed that those in the highest moderate-to-vigorous physical activity tertile presented lower cognitive performance scores at 18 yr as compared with those in the lowest tertile (-2.59; 95% confidence interval (CI), -3.41 to -1.48). Analyses on changes in tertiles of physical activity showed that maintaining an intermediate physical activity level from 11 to 18 yr and from 15 to 18 yr was associated with a higher cognitive performance score of 2.31 (95% CI, 0.71–3.91) and 1.84 score (95% CI, 0.25–3.42), respectively. Conclusions: Physical activity throughout adolescence is associated with cognitive performance before adulthood. Adolescents who are active at moderate levels, specifically those who maintain these levels of physical activity, tend to show higher cognitive performance. However, high levels of physical activity might impair cognitive performance.

• Shoham, David A.; Dugas, Lara R.; Bovet, Pascal; Forrester, Terrence; Lambert, Estelle V. & Plange-Rhule, Jacob [Show all 12 contributors for this article] (2015). Association of car ownership and physical activity across the spectrum of human development: Modeling the Epidemiologic Transition Study (METS). BMC Public Health. 14(173). doi: 10.1186/s12889-015-1435-9. Full text in Research Archive
• Golubic, R; Wijndaele, K; Sharp, SJ; Simmons, RK; Griffin, SJ & Wareham, NJ [Show all 8 contributors for this article] (2015). Physical activity, sedentary time and gain in overall and central body fat: 7-year follow-up of the ProActive trial cohort. International Journal of Obesity. ISSN 0307-0565. 39(1), p. 142–148. doi: 10.1038/ijo.2014.66. Full text in Research Archive
• Horta, Bernardo L.; Schaan, Beatriz D.; Bielemann, Renata M; Vianna, Carolina Avila; Gigante, D. Petrucci & Barros, Fernando C. [Show all 8 contributors for this article] (2015). Objectively measured physical activity and sedentary-time are associated with arterial stiffness in Brazilian young adults. Atherosclerosis. ISSN 0021-9150. 243(1), p. 148–154. doi: 10.1016/j.atherosclerosis.2015.09.005. Full text in Research Archive Show summary

  Objective: To examine the associations between objectively measured physical activity and sedentary time with pulse wave velocity (PWV) in Brazilian young adults. Methods: Cross-sectional analysis with participants of the 1982 Pelotas (Brazil) Birth Cohort who were followed-up from birth to 30 years of age. Overall physical activity (PA) assessed as the average acceleration (mg), time spent in moderate-to-vigorous physical activity (MVPA – min/day) and sedentary time (min/day) were calculated from acceleration data. Carotid-femoral PWV (m/s) was assessed using a portable ultrasound. Systolic and diastolic blood pressure (SBP/DBP), waist circumference (WC) and body mass index (BMI) were analyzed as possible mediators. Multiple linear regression and g-computation formula were used in the analyses. Results: Complete data were available for 1241 individuals. PWV was significantly lower in the two highest quartiles of overall PA (0.26 m/s) compared with the lowest quartile. Participants in the highest quartile of sedentary time had 0.39 m/s higher PWV (95%CI: 0.20; 0.57) than those in the lowest quartile. Individuals achieving ≥30 min/day in MVPA had lower PWV (β = −0.35; 95%CI: −0.56; −0.14). Mutually adjusted analyses between MVPA and sedentary time and PWV changed the coefficients, although results from sedentary time remained more consistent. WC captured 44% of the association between MVPA and PWV. DBP explained 46% of the association between acceleration and PWV. Conclusions: Physical activity was inversely related to PWV in young adults, whereas sedentary time was positively associated.

• Brage, Søren; Westgate, Kate; Franks, Paul W.; Stegle, Oliver; Wright, Antony & Ekelund, Ulf [Show all 7 contributors for this article] (2015). Estimation of Free-Living Energy Expenditure by Heart Rate and Movement Sensing: A Doubly-Labelled Water Study. PLOS ONE. 10(9). doi: 10.1371/journal.pone.0137206. Full text in Research Archive Show summary

  Background: Accurate assessment of energy expenditure (EE) is important for the study of energy balance and metabolic disorders. Combined heart rate (HR) and acceleration (ACC) sensing may increase precision of physical activity EE (PAEE) which is the most variable component of total EE (TEE). Objective: To evaluate estimates of EE using ACC and HR data with or without individual calibration against doubly-labelled water (DLW) estimates of EE. Design: 23 women and 23 men (22–55 yrs, 48–104 kg, 8–46%body fat) underwent 45-min resting EE (REE) measurement and completed a 20-min treadmill test, an 8-min step test, and a 3-min walk test for individual calibration. ACC and HR were monitored and TEE measured over 14 days using DLW. Diet-induced thermogenesis (DIT) was calculated from food-frequency questionnaire. PAEE (TEE ÷ REE ÷ DIT) and TEE were compared to estimates from ACC and HR using bias, root mean square error (RMSE), and correlation statistics. Results: Mean(SD) measured PAEE and TEE were 66(25) kJ·day-1·kg-1, and 12(2.6) MJ·day-1, respectively. Estimated PAEE from ACC was 54(15) kJ·day-1·kg-1 (p<0.001), with RMSE 24 kJ·day-1·kg-1 and correlation r = 0.52. PAEE estimated from HR and ACC+HR with treadmill calibration were 67(42) and 69(25) kJ·day-1·kg-1 (bias non-significant), with RMSE 34 and 20 kJ·day-1·kg-1 and correlations r = 0.58 and r = 0.67, respectively. Similar results were obtained with step-calibrated and walk-calibrated models, whereas non-calibrated models were less precise (RMSE: 37 and 24 kJ·day-1·kg-1, r = 0.40 and r = 0.55). TEE models also had high validity, with biases <5%, and correlations r = 0.71 (ACC), r = 0.66–0.76 (HR), and r = 0.76–0.83 (ACC+HR). Conclusions: Both accelerometry and heart rate may be used to estimate EE in adult European men and women, with improved precision if combined and if heart rate is individually calibrated

• Cooper, Ashley R.; Goodman, Anna; Page, Angie S.; Sherar, Lauren B.; Esliger, Dale W. & Sluijs, Esther M.F. van [Show all 22 contributors for this article] (2015). Objectively measured physical activity and sedentary time in youth: the International children’s accelerometry database (ICAD). International Journal of Behavioral Nutrition and Physical Activity. 12:113. doi: 10.1186/s12966-015-0274-5. Full text in Research Archive Show summary

  Background: Physical activity and sedentary behaviour in youth have been reported to vary by sex, age, weight status and country. However, supporting data are often self-reported and/or do not encompass a wide range of ages or geographical locations. This study aimed to describe objectively-measured physical activity and sedentary time patterns in youth. Methods: The International Children’s Accelerometry Database (ICAD) consists of ActiGraph accelerometer data from 20 studies in ten countries, processed using common data reduction procedures. Analyses were conducted on 27,637 participants (2.8–18.4 years) who provided at least three days of valid accelerometer data. Linear regression was used to examine associations between age, sex, weight status, country and physical activity outcomes. Results: Boys were less sedentary and more active than girls at all ages. After 5 years of age there was an average cross-sectional decrease of 4.2 % in total physical activity with each additional year of age, due mainly to lower levels of light-intensity physical activity and greater time spent sedentary. Physical activity did not differ by weight status in the youngest children, but from age seven onwards, overweight/obese participants were less active than their normal weight counterparts. Physical activity varied between samples from different countries, with a 15–20 % difference between the highest and lowest countries at age 9–10 and a 26–28 % difference at age 12–13. Conclusions: Physical activity differed between samples from different countries, but the associations between demographic characteristics and physical activity were consistently observed. Further research is needed to explore environmental and sociocultural explanations for these differences.

• Johansson, Elin; Ekelund, Ulf; Nero, H.; Marcus, C. & Hagströmer, Maria (2015). Calibration and cross-validation of a wrist-worn Actigraph in young preschoolers. Pediatric Obesity. ISSN 2047-6302. 10(1), p. 1–6. doi: 10.1111/j.2047-6310.2013.00213.x. Full text in Research Archive Show summary

  Objective: To calibrate the Actigraph GT3X+ accelerometer for wrist-worn placement in young preschoolers by developing intensity thresholds for sedentary, low- and high-intensity physical activity. Furthermore, to cross-validate the developed thresholds in young preschoolers. Methods: Actigraph GT3X+ was used to measure physical activity during structured activities and free play in 38 children (15–36 months). Activity was video recorded and scored into sedentary, low- and high-intensity physical activity based on Children's Activity Rating Scale (CARS) and combined with accelerometer data using a 5 s epoch. Receiver operating characteristic analysis was used to develop intensity thresholds in 26 randomly selected children. The remaining 12 children were used for cross-validation. Results: Intensity thresholds for sedentary were ≤89 vertical counts (Y) and ≤221 vector magnitude (VM) counts per 5 s and ≥440 Y counts and ≥730 VM counts per 5 s for high-intensity physical activity. Sensitivity and specificity were 60–100% for the developed intensity thresholds. Strong correlations (Spearman rank correlation 0.69–0.91) were found in the cross-validation sample between the developed thresholds for the accelerometer and CARS scoring time in all intensity categories. Conclusion: The developed intensity thresholds appear valid to categorize sedentary behaviour and physical activity intensity categories in children 2 years of age.

• Corder, Kirsten; Atkin, Andrew J.; Bamber, Diane J.; Brage, Søren; Dunn, Valerie J. & Ekelund, Ulf [Show all 9 contributors for this article] (2015). Revising on the run or studying on the sofa: prospective associations between physical activity, sedentary behaviour, and exam results in British adolescents. International Journal of Behavioral Nutrition and Physical Activity. 12(1). doi: 10.1186/s12966-015-0269-2. Full text in Research Archive Show summary

  Background: We investigated prospective associations between physical activity/sedentary behaviour (PA/SED) and General Certificate of Secondary Education (GCSE) results in British adolescents. Methods: Exposures were objective PA/SED and self-reported sedentary behaviours (screen (TV, Internet, Computer Games)/non-screen (homework, reading)) measured in 845 adolescents (14·5y ± 0·5y; 43·6 % male). GCSE results at 16y were obtained from national records. Associations between exposures and academic performance (total exam points) were assessed using multilevel mixed-effects linear regression adjusted for mood, BMI z-score, deprivation, sex, season and school; potential interactions were investigated. Results: PA was not associated with academic performance. One-hour more accelerometer-assessed SED was associated with (β(95 % CI)) 6·9(1·5,12·4) more GCSE points. An extra hour of screen time was associated with 9.3(−14·3,-4·3) fewer points whereas an extra hour of non-screen time (reading/homework) was associated with 23·1(14·6,31·6) more points. Screen time was still associated with poorer scores after adjusting for objective PA/SED and reading/homework. Conclusions: An extra hour/day of screen time at 14·5y is approximately equivalent to two fewer GCSE grades (e.g., from B to D) at 16y. Strategies to achieve the right balance between screen and non-screen time may be important for improving academic performance. Concerns that encouraging more physical activity may result in decreased academic performance seem unfounded.

• Harrison, Flo; Sluijs, Esther M.F. van; Corder, Kirsten; Ekelund, Ulf & Jones, Andy (2015). The changing relationship between rainfall and children's physical activity in spring and summer: A longitudinal study. International Journal of Behavioral Nutrition and Physical Activity. 12(1). doi: 10.1186/s12966-015-0202-8. Full text in Research Archive Show summary

  Background Weather conditions, along with day length, are proposed as the main drivers of the seasonal patterns in children’s physical activity (PA), but little is known about how they affect children at different ages. This study examines the relationship between rainfall and PA in a longitudinal cohort of initially 9–10 year-old children in Norfolk, UK. Methods Participants were 283 children from the SPEEDY study who wore accelerometers ≤7 days on three occasions in the summer of 2007, 2008 and 2011 at ages 9–10, 10–11, and 13-14y. Daily weather data were obtained for two local weather stations. Relationships between rainfall and PA (moderate-to-vigorous-PA (MVPA; ≥2000) vigorous PA (VPA; ≥4000), counts per minute (cpm)) and sedentary time were assessed in multiple-membership multilevel models. PA was assessed over the whole day, and over parts of the school day; commute time (8 am-9 am and 3 pm-4 pm), lunchtime (12noon-2 pm), and after school (4 pm-9 pm). Results: At ages 9–10 and 10-11y, PA declined with increasing rainfall, with an average of 14.0 (SE 2.9) and 11.4 (3.0) minutes less MVPA on the wettest days (≥1.7 mm rain) compared to dry days respectively. There was no significant trend in MVPA across rainfall categories at age 13–14 years. Between ages 9–10 and 13–14, MVPA decline was largest on dry days (-15.2 (2.7) minutes). These patterns were also apparent during school lunchtime and after school, however they were not seen during school commute times. Similar patterns were seen for other PA intensities. Conclusions: Increased rainfall is associated with significant decreases in PA among primary school children, but not secondary school children. PA declines most steeply between the ages of 9–10 and 13–14 on dry days. Interventions to increase activity on wet days may be most relevant at primary schools. Our results also highlight the importance of habitualising behavior to make children more resilient both to bad weather, and potentially age-related decline in activity.

• Janssen, Xanne; Cliff, Dylan; Reilly, John J.; Hinkley, Trina; Jones, Rachel & Batterham, Marijka [Show all 9 contributors for this article] (2015). Evaluation of Actical equations and thresholds to predict physical activity intensity in young children. Journal of Sports Sciences. ISSN 0264-0414. 33(5), p. 498–506. doi: 10.1080/02640414.2014.949826. Full text in Research Archive
• Corder, Kirsten; Sluijs, Esther M.F. van; Ridgway, Charlotte L.; Steele, Rebekah M.; Prynne, Celia J. & Stephen, Alison M. [Show all 10 contributors for this article] (2014). Breakfast consumption and physical activity in adolescents: Daily associations and hourly patterns1-3. American Journal of Clinical Nutrition. ISSN 0002-9165. 99(2), p. 361–368. doi: 10.3945/ajcn.111.027607. Full text in Research Archive Show summary

  Background: The association between breakfast consumption and physical activity (PA) is inconclusive. Objective: We aimed to investigate daily associations and hourly patterns of PA and breakfast consumption in British adolescents. Design: Daily PA [accelerometry-derived moderate and vigorous physical activity (MVPA)] and breakfast consumption (diet diary) were measured simultaneously over 4 d in 860 adolescents (boys: 43.4%; mean ± SD age: 14.5 ± 0.5 y). Associations between MVPA and breakfast consumption were assessed by using a multilevel mixed-effects logistic regression separately by sex and for weekends and weekdays. Hourly patterns of MVPA by breakfast consumption status were displayed graphically, and differences were tested by using ANOVA. Multilevel linear regression was used to investigate differences in log MVPA on days when 570 inconsistent breakfast consumers ate or skipped breakfast. Results: On weekends, boys and girls with higher MVPA were more likely to eat breakfast [OR (95% CI): boys, 1.78 (1.30, 2.45) (P < 0.001); girls, 2.30 (1.66, 3.08) (P < 0.001)] when adjusted for socioeconomic status, percentage of body fat, and total energy intake. Peak hourly MVPA differed for breakfast consumers compared with nonconsumers on weekends (P < 0.001). Inconsistent breakfast consumers did more MVPA on days when they ate breakfast [exponentiated β coefficients (95% CIs): 1.2 (1.0, 1.5) on weekdays and 1.4 (1.1, 1.8) on weekends for boys and 1.6 (1.3, 2.1) on weekends for girls; all P < 0.03]. Conclusions: Eating breakfast was associated with higher MVPA on weekends. The time of peak MVPA differed between breakfast consumers and nonconsumers on weekends. Breakfast consumption at weekends is worth additional investigation to potentially inform PA promotion in adolescents.

• España-Romero, Vanesa; Golubic, Rajna; Martin, Kathryn R.; Hardy, Rebecca; Ekelund, Ulf & Kuh, Diana [Show all 9 contributors for this article] (2014). Comparison of the EPIC Physical Activity Questionnaire with Combined Heart Rate and Movement Sensing in a Nationally Representative Sample of Older British Adults. PLOS ONE. 9(2). doi: 10.1371/journal.pone.0087085. Full text in Research Archive
• Golubic, Rajna; Martin, Kathryn R.; Ekelund, Ulf; Hardy, Rebecca; Kuh, Diana & Wareham, Nicholas [Show all 8 contributors for this article] (2014). Levels of physical activity among a nationally representative sample of people in early old age: results of objective and self-reported assessments. International Journal of Behavioral Nutrition and Physical Activity. 11(1). doi: 10.1186/1479-5868-11-58. Full text in Research Archive
• Griffin, Tania L; Pallan, Miranda J; Clarke, Joanne L; Lancashire, Emma R; Lyon, Anna & Parry, Jane M [Show all 20 contributors for this article] (2014). Process evaluation design in a cluster randomised controlled childhood obesity prevention trial: the WAVES study. International Journal of Behavioral Nutrition and Physical Activity. 11. doi: 10.1186/s12966-014-0112-1. Full text in Research Archive
• Øglund, Guro Pauck; Stensrud, Trine & Ekelund, Ulf (2014). Early life determinants of physical activity and sedentary time: Current knowledge and future research. Norsk Epidemiologi. ISSN 0803-2491. 24(1-2), p. 177–186. doi: 10.5324/nje.v24i1-2.1820. Full text in Research Archive Show summary

  Previous findings of the association between low birth weight and subsequent health outcomes have led to the “developmental origins of health and disease hypothesis”. Furthermore, modifiable and partly modifiable early life factors may also influence behaviors such as physical activity and sedentary behavior. The aim of the present review was to summarize the existing knowledge on early life determinants (birth weight, rapid infant weight gain, motor development and infant temperament) of childhood physical activity and sedentary time, and suggest opportunities for future research based on the Mother and Child Cohort Study (MoBa). Inconsistent results have been observed when relating birth weight to later physical activity, likely explained by differences in methodology when assessing physical activity between studies. There is limited data on whether rapid weight gain in early life predicts later physical activity and few studies have examined the association between birth weight and infant weight gain with subsequent sedentary time. Motor development may be a predictor for childhood physical activity, however methodological limitations preclude firm conclusions. The association between motor development and sedentary time has rarely been examined. Conflicting results have been reported for the association between infant temperament and subsequent physical activity and sedentary time in toddlers. Finally, it is unknown whether physical activity modifies the association between birth weight, postnatal weight gain, and later health outcomes in youth. Additional research in well-characterized birth cohorts can be used to generate new knowledge on possible early life determinants of children’s and youth’s physical activity and sedentary time which may inform evidence-based public health interventions.

• Janssen, Xanne; Cliff, Dylan P.; Reilly, John J.; Hinkley, Trina; Jones, Rachel A. & Batterham, Marijka [Show all 9 contributors for this article] (2014). Validation and calibration of the activPAL™ for estimating METs and physical activity in 4–6 year olds. Journal of Science and Medicine in Sport. ISSN 1440-2440. 17(6), p. 602–606. doi: 10.1016/j.jsams.2013.10.252. Full text in Research Archive
• Arango, Carlos M.; Parra, Diana C.; Gómez, Luis F.; Lema, Lucía; Lobelo, Felipe & Ekelund, Ulf (2014). Screen time, cardiorespiratory fitness and adiposity among school-age children from Monteria, Colombia. Journal of Science and Medicine in Sport. ISSN 1440-2440. 17(5), p. 491–495. doi: 10.1016/j.jsams.2013.09.010. Full text in Research Archive
• Santos, Diana A.; Silva, Analiza M.; Matias, Catarina N.; Magalhães, João P.; Fields, David A. & Minderico, Cláudia S. [Show all 8 contributors for this article] (2014). Validity of a combined heart rate and motion sensor for the measurement of free-living energy expenditure in very active individuals. Journal of Science and Medicine in Sport. ISSN 1440-2440. 17(4), p. 387–393. doi: 10.1016/j.jsams.2013.09.006. Full text in Research Archive
• Shen, Dong; Mao, Weidong; Liu, Tao; Lin, Quingfeng; Lu, Xiangdong & Wang, Qiong [Show all 9 contributors for this article] (2014). Sedentary behavior and incident cancer: a meta-analysis of prospective studies. PLOS ONE. 9:e0105709(8). doi: 10.1371/journal.pone.0105709. Full text in Research Archive
• Bryant, M.; Ashton, L.; Nixon, J.; Jebb, S.; Wright, J. & Roberts, K. [Show all 17 contributors for this article] (2014). Framework of outcome measures recommended for use in the evaluation of childhood obesity treatment interventions: the CoOR framework. Pediatric Obesity. ISSN 2047-6302. 9(6), p. e116–e131. doi: 10.1111/j.2047-6310.2014.220.x. Full text in Research Archive
• Grøntved, Anders; Ried-Larsen, Mathias; Møller, Niels Christian; Kristensen, Peter Lund; Wedderkopp, Niels & Froberg, Karsten [Show all 9 contributors for this article] (2014). Youth screen-time behaviour is associated with cardiovascular risk in young adulthood: the European Youth Heart Study. European Journal of Preventive Cardiology (EJPC). ISSN 2047-4873. 21(1), p. 49–56. doi: 10.1177/2047487312454760. Full text in Research Archive Show summary

  Aims: We prospectively examined the association of TV viewing, computer use, and total screen time in adolescence, and change in these behaviours, with cardiovascular disease (CVD) risk factors in young adulthood. Methods and results: This was a prospective cohort study among Danish men and women (n = 435) followed for up to 12 years. Adiposity, blood pressure (BP), triglycerides, high-density lipoprotein (HDL), glucose, insulin, and self-reported TV viewing and computer use were obtained in adolescence and in young adulthood. A continuous metabolic syndrome z-score was calculated as the sum of standardized values of each risk factor (inverse of HDL). In multivariable-adjusted analyses, TV viewing and total screen time in adolescence were positively associated with adiposity, triglycerides, and metabolic syndrome z-score in young adulthood (p < 0.05). Individuals who increased their TV viewing, computer use, or total screen time with more than 2 hours/day from adolescence to young adulthood had 0.90 (95% CI 0.12 to 1.69), 0.95 (95% CI 0.01 to 1.88), and 1.40 (95% CI 0.28 to 2.51) kg/m2 higher body mass index, respectively, in young adulthood compared with individuals who remained stable or decreased their viewing time. Insulin and metabolic syndrome z-scores were also higher among individuals who increased their TV viewing, computer use, or total screen time more than 2 hours/day compared with individuals who remained stable or decreased their viewing time (p < 0.05). Conclusions: Prolonged TV viewing and total screen time during leisure time in adolescence, and increases in these behaviours, are associated with unfavourable levels of several cardiovascular risk factors in young adulthood.

• Cooper, Andrew J.M.; Brage, Søren; Ekelund, Ulf; Wareham, Nicholas J.; Griffin, Simon J. & Simmons, Rebecca K. (2014). Association between objectively assessed sedentary time and physical activity with metabolic risk factors among people with recently diagnosed type 2 diabetes. Diabetologia. ISSN 0012-186X. 57(1), p. 73–82. doi: 10.1007/s00125-013-3069-8. Full text in Research Archive
• Griffin, Simon J.; Simmons, Rebecca K.; Prevost, A. Toby; Williams, Kate M.; Hardeman, Wendy & Sutton, Stephen [Show all 11 contributors for this article] (2014). Multiple behaviour change intervention and outcomes in recently diagnosed type 2 diabetes: the ADDITION-Plus randomised controlled trial. Diabetologia. ISSN 0012-186X. 57(7), p. 1308–1319. doi: 10.1007/s00125-014-3236-6. Full text in Research Archive
• Wijndaele, Katrien; Orrow, Gillian; Ekelund, Ulf; Sharp, Stephen J.; Brage, Søren & Griffin, Simon J. [Show all 7 contributors for this article] (2014). Increasing objectively measured sedentary time increases clustered cardiometabolic risk: a 6 year analysis of the ProActive study. Diabetologia. ISSN 0012-186X. 57(2), p. 305–312. doi: 10.1007/s00125-013-3102-y. Full text in Research Archive
• Hesketh, Kathryn R.; Goodfellow, Laura; Ekelund, Ulf; McMinn, Alison M.; Godfrey, Keith M. & Inskip, Hazel M. [Show all 9 contributors for this article] (2014). Activity levels in mothers and their preschool children. Pediatrics. ISSN 0031-4005. 133(4), p. e973–e980. doi: 10.1542/peds.2013-3153. Full text in Research Archive
• Hildebrand, Maria; Hees, Vincent T. van; Hansen, Bjørge Hermann & Ekelund, Ulf (2014). Age-Group Comparability of Raw Accelerometer Output from Wrist- and Hip-Worn Monitors. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 46(9), p. 1816–1824. doi: 10.1249/MSS.0000000000000289. Full text in Research Archive Show summary

  Purpose: The study aims were to compare raw triaxial accelerometer output from ActiGraph GT3X+ (AG) and GENEActiv (GA) placed on the hip and the wrist and to develop regression equations for estimating energy expenditure. Methods: Thirty children (7–11 yr) and 30 adults (18–65 yr) completed eight activities (ranging from lying to running) while wearing one AG and one GA on the hip and the wrist. Oxygen consumption (V·O2) was measured with indirect calorimetry. Analysis involved the use of ANOVA to examine the effect of activity, brand, and placement on the acceleration values, intraclass correlation coefficient to evaluate the agreement between the two brands and placements, and linear regression to establish intensity thresholds. Results: A significant difference in acceleration values between the hip and the wrist placement was found (P < 0.001). The output from the wrist placement was, in general, higher compared with that from the hip. There was no main effect of monitor brand in adults (P < 0.12) and children (P < 0.73), and the intraclass correlation coefficient showed a strong agreement (0.96–0.99). However, a three-way interaction and systematic error between the brands was found in children. Acceleration from both brands and placements showed a strong correlation with V·O2. The intensity classification accuracy of the developed thresholds for both brands and placements was, in general, higher for adults compared with that for children and was greater for sedentary/light (93%–97%), and vigorous activities (68%–92%) than that for moderate activities (33%–59%). Conclusions: Accelerometer outputs from AG and GA seem comparable when attached to the same body location in adults, whereas inconsistent differences are apparent between the two brands and placements in children, hence limiting the comparability between brands in this age group.

• Ekelund, Ulf; Hildebrand, Maria & Collings, Paul J. (2014). Physical activity, sedentary time and adiposity during the first two decades of life. Proceedings of the Nutrition Society. ISSN 0029-6651. 73(2), p. 319–329. doi: 10.1017/S0029665114000019. Full text in Research Archive Show summary

  High amounts of time spent sedentary and low levels of physical activity have been implicated in the process of excessive adiposity gains in youth. The aim of this review is to discuss the role of physical activity, sedentary time and behaviour (i.e. television (TV)-viewing) in relation to adiposity during the first two decades of life with a specific focus on whether the association between sedentary time, and behaviour and adiposity is independent of physical activity. We identified nine cohort studies (three prospective) whether sedentary time was associated with adiposity independent of physical activity. Eight of these studies suggested that sedentary time was unrelated to adiposity when physical activity was taken into account. Results from studies (n 8) examining the independent association between TV-viewing and adiposity independent of physical activity were mixed. Those that observed a positive association between TV-viewing and adiposity independent of physical activity discussed that the association may be due to residual confounding. A few additional studies have also challenged the general notion that low levels of physical activity leads to fatness and suggested that higher baseline fatness may be predictive of a decline in physical activity. It appears unlikely that higher levels of sedentary time are associated with or predictive of, higher levels of adiposity when physical activity is controlled for in youth. Specific sedentary behaviours such as TV-viewing may be associated with adiposity independent of physical activity but the results may be explained by residual confounding.

• Dugas, Lara R; Bovet, Pascal; Forrester, Terrence E; Lambert, Estelle V; Plange-Rhule, Jacob & Durazo-Arvizu, Ramon A [Show all 13 contributors for this article] (2014). Comparisons of intensity-duration patterns of physical activity in the US, Jamaica and 3 African countries. BMC Public Health. 14. doi: 10.1186/1471-2458-14-882. Full text in Research Archive
• Luke, Amy; Bovet, Pascal; Plange-Rhule, Jacob; Forrester, Terrence E.; Lambert, Estelle & Schoeller, Dale A. [Show all 13 contributors for this article] (2014). A mixed ecologic-cohort comparison of physical activity &amp; weight among young adults from five populations of African origin. BMC Public Health. 14. doi: 10.1186/1471-2458-14-397. Full text in Research Archive
• Hesketh, Kathryn R.; McMinn, Alison M.; Ekelund, Ulf; Sharp, Stephen J.; Collings, Paul J. & Harvey, Nicholas C. [Show all 10 contributors for this article] (2014). Objectively measured physical activity in four-year-old British children: a cross-sectional analysis of activity patterns segmented across the day. International Journal of Behavioral Nutrition and Physical Activity. 11:1. doi: 10.1186/1479-5868-11-1. Full text in Research Archive
• Adab, Peymane; Pallan, Miranda J; Cade, Janet; Ekelund, Ulf; Barrett, Timothy & Daley, Amanda [Show all 12 contributors for this article] (2014). Preventing childhood obesity, phase II feasibility study focusing on South Asians: BEACHeS. BMJ Open. 4. doi: 10.1136/bmjopen-2013-004579. Full text in Research Archive
• Wientzek, A; Diaz, MJ Tormo; Castano, JMH; Amiano, P; Arriola, L & Overvad, K [Show all 25 contributors for this article] (2014). Cross-sectional associations of objectively measured physical activity, cardiorespiratory fitness and anthropometry in european adults. Obesity. ISSN 1930-7381. 22(5), p. E127–E134. doi: 10.1002/oby.20530. Full text in Research Archive Show summary

  Objective: To quantify the independent associations between objectively measured physical activity (PA), cardiorespiratory fitness (CRF), and anthropometry in European men and women.<p> <p>Methods: 2,056 volunteers from 12 centers across Europe were fitted with a heart rate and movement sensor at 2 visits 4 months apart for a total of 8 days. CRF (ml/kg/min) was estimated from an 8 minute ramped step test. A cross-sectional analysis of the independent associations between objectively measured PA (m/s2 /d), moderate and vigorous physical activity (MVPA) (%time/d), sedentary time (%time/d), CRF, and anthropometry using sex stratified multiple linear regression was performed. <p>Results: In mutually adjusted models, CRF, PA, and MVPA were inversely associated with all anthropometric markers in women. In men, CRF, PA, and MVPA were inversely associated with BMI, whereas only CRF was significantly associated with the other anthropometric markers. Sedentary time was positively associated with all anthropometric markers, however, after adjustment for CRF significant in women only. <p>Conclusion: CRF, PA, MVPA, and sedentary time are differently associated with anthropometric markers in men and women. CRF appears to attenuate associations between PA, MVPA, and sedentary time. These observations may have implications for prevention of obesity.

• Collings, Paul J.; Wijndaele, Katrien; Corder, Kirsten; Westgate, Kate; Ridgway, Charlotte L. & Dunn, Valerie [Show all 9 contributors for this article] (2014). Levels and patterns of objectively-measured physical activity volume and intensity distribution in UK adolescents: the ROOTS study. International Journal of Behavioral Nutrition and Physical Activity. 11(1). doi: 10.1186/1479-5868-11-23. Full text in Research Archive
• Rogers, Annabelle; Harris, Tess; Victor, Christina; Woodcock, Alison; Limb, Elizabeth & Kerry, Sally [Show all 13 contributors for this article] (2014). Which older people decline participation in a primary care trial of physical activity and why: insights from a mixed methods approach. BMC Geriatrics. 14. doi: 10.1186/1471-2318-14-46. Full text in Research Archive
• Silva, Inácio CM da; Hees, Vincent T. van; Ramires, Virgílio V; Knuth, Alan G; Bielemann, Renata M & Ekelund, Ulf [Show all 8 contributors for this article] (2014). Physical activity levels in three Brazilian birth cohorts as assessed with raw triaxial wrist accelerometry. International Journal of Epidemiology. ISSN 0300-5771. 43(6), p. 1959–1968. doi: 10.1093/ije/dyu203. Full text in Research Archive
• Orme, Mark; Wijndaele, Katrien; Sharp, Stephen J.; Westgate, Kate; Ekelund, Ulf & Brage, Søren Karl (2014). Combined influence of epoch length, cut-point and bout duration on accelerometry-derived physical activity. International Journal of Behavioral Nutrition and Physical Activity. 11(1). doi: 10.1186/1479-5868-11-34. Full text in Research Archive
• Lakerveld, Jeroen; Ploeg, Hidde P van der; Kroetze, Willemieke; Ahrens, Wolfgang; Allais, Olivier & Andersen, Lene Frost [Show all 35 contributors for this article] (2014). Towards the integration and development of a cross-European research network and infrastructure: the Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub. International Journal of Behavioral Nutrition and Physical Activity. 11, p. 143–143. doi: 10.1186/s12966-014-0143-7. Full text in Research Archive Show summary

  To address major societal challenges and enhance cooperation in research across Europe, the European Commission has initiated and facilitated `joint programming’. Joint programming is a process by which Member States engage in defining, developing and implementing a common strategic research agenda, based on a shared vision of how to address major societal challenges that no Member State is capable of resolving independently. Setting up a Joint Programming Initiative (JPI) should also contribute to avoiding unnecessary overlap and repetition of research, and enable and enhance the development and use of standardised research methods, procedures and data management. The Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub (KH) is the first act of the European JPI `A Healthy Diet for a Healthy Life’. The objective of DEDIPAC is to contribute to improving understanding of the determinants of dietary, physical activity and sedentary behaviours. DEDIPAC KH is a multi-disciplinary consortium of 46 consortia and organisations supported by joint programming grants from 12 countries across Europe. The work is divided into three thematic areas: (I) assessment and harmonisation of methods for future research, surveillance and monitoring, and for evaluation of interventions and policies; (II) determinants of dietary, physical activity and sedentary behaviours across the life course and in vulnerable groups; and (III) evaluation and benchmarking of public health and policy interventions aimed at improving dietary, physical activity and sedentary behaviours. In the first three years, DEDIPAC KH will organise, develop, share and harmonise expertise, methods, measures, data and other infrastructure. This should further European research and improve the broad multi-disciplinary approach needed to study the interactions between multilevel determinants in influencing dietary, physical activity and sedentary behaviours. Insights will be translated into more effective interventions and policies for the promotion of healthier behaviours and more effective monitoring and evaluation of the impacts of such interventions.

• Janssen, Xanne; Cliff, Dylan P.; Reilly, John J.; Hinkley, Trina; Jones, Rachel A. & Batterham, Marijka [Show all 9 contributors for this article] (2014). Validation of activPAL defined sedentary time and breaks in sedentary time in 4- to 6-year-olds. Pediatric Exercise Science. ISSN 0899-8493. 26(1), p. 110–117. doi: 10.1123/pes.2013-0106. Full text in Research Archive Show summary

  This study examined the classification accuracy of the activPAL, including total time spent sedentary and total number of breaks in sedentary behavior (SB) in 4- to 6-year-old children. Forty children aged 4–6 years (5.3 ± 1.0 years) completed a ~150-min laboratory protocol involving sedentary, light, and moderate- to vigorous-intensity activities. Posture was coded as sit/lie, stand, walk, or other using direct observation. Posture was classified using the activPAL software. Classification accuracy was evaluated using sensitivity, specificity and area under the receiver operating characteristic curve (ROC-AUC). Time spent in each posture and total number of breaks in SB were compared using paired sample t-tests. The activPAL showed good classification accuracy for sitting (ROC-AUC = 0.84) and fair classification accuracy for standing and walking (0.76 and 0.73, respectively). Time spent in sit/lie and stand was overestimated by 5.9% (95% CI = 0.6–11.1%) and 14.8% (11.6–17.9%), respec- tively; walking was underestimated by 10.0% (–12.9–7.0%). Total number of breaks in SB were significantly overestimated (55 ± 27 over the course of the protocol; p < .01). The activPAL performed well when classifying postures in young children. However, the activPAL has difficulty classifying other postures, such as kneeling. In addition, when predicting time spent in different postures and total number of breaks in SB the activPAL appeared not to be accurate.

• Harris, Tess; Kerry, Sally; Victor, Christina; Ekelund, Ulf; Woodcock, Alison & Iliffe, Steve [Show all 14 contributors for this article] (2013). Randomised controlled trial of a complex intervention by primary care nurses to increase walking in patients aged 60-74 years: protocol of the PACE-Lift (Pedometer Accelerometer Consultation Evaluation - Lift) trial. BMC Public Health. 13. doi: 10.1186/1471-2458-13-5. Full text in Research Archive Show summary

  Physical activity is essential for older people's physical and mental health and for maintaining independence. Guidelines recommend at least 150 minutes weekly, of at least moderate intensity physical activity, with activity on most days. Older people's most common physical activity is walking, light intensity if strolling, moderate if brisker. Less than 20% of United Kingdom 65-74 year olds report achieving the guidelines, despite most being able to. Effective behaviour change techniques include strategies such as goal setting, self-monitoring, building self-efficacy and relapse prevention. Primary care physical activity consultations allow individual tailoring of advice. Pedometers measure step-counts and accelerometers measure physical activity intensity. This protocol describes an innovative intervention to increase walking in older people, incorporating pedometer and accelerometer feedback within a primary care nurse physical activity consultation, using behaviour change techniques.

• Hallal, Pedro C.; Reichert, Felipe F.; Clark, Valerie L.; Cordeira, Kelly L.; Menezes, Ana M.B. & Eaton, Simon [Show all 8 contributors for this article] (2013). Energy expenditure compared to physical activity measured by accelerometry and self-report in adolescents: a validation study. PLOS ONE. 8(11:e77036). doi: 10.1371/journal.pone.0077036. Full text in Research Archive Show summary

  Background: Physical inactivity is responsible for 5.3 million deaths annually worldwide. To measure physical activity energy expenditure, the doubly labeled water (DLW) method is the gold standard. However, questionnaires and accelerometry are more widely used. We compared physical activity measured by accelerometer and questionnaire against total (TEE) and physical activity energy expenditure (PAEE) estimated by DLW. Methods: TEE, PAEE (TEE minus resting energy expenditure) and body composition were measured using the DLW technique in 25 adolescents (16 girls) aged 13 years living in Pelotas, Brazil. Physical activity was assessed using the Actigraph accelerometer and by self-report. Physical activity data from accelerometry and self-report were tested against energy expenditure data derived from the DLW method. Further, tests were done to assess the ability of moderate-to-vigorous intensity physical activity (MVPA) to predict variability in TEE and to what extent adjustment for fat and fat-free mass predicted the variability in TEE. Results: TEE varied from 1,265 to 4,143 kcal/day. It was positively correlated with physical activity (counts) estimated by accelerometry (rho = 0.57; p = 0.003) and with minutes per week of physical activity by questionnaire (rho = 0.41; p = 0.04). An increase of 10 minutes per day in moderate-to-vigorous intensity physical activity (MVPA) relates to an increase in TEE of 141 kcal/day. PAEE was positively correlated with accelerometry (rho = 0.64; p = 0.007), but not with minutes per week of physical activity estimated by questionnaire (rho = 0.30; p = 0.15). Physical activity by accelerometry explained 31% of the vssariability in TEE. By incorporating fat and fat-free mass in the model, we were able to explain 58% of the variability in TEE. Conclusion: Objectively measured physical activity significantly contributes to the explained variance in both TEE and PAEE in Brazilian youth. Independently, body composition also explains variance in TEE, and should ideally be taken into account when using accelerometry to predict energy expenditure values.

• Hoed, Marcel den; Eijgelsheim, M; Esko, T; Brundel, BJJM; Peal, DS & Evans, DM [Show all 268 contributors for this article] (2013). Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders. Nature Genetics. ISSN 1061-4036. 45(6), p. 621–631. doi: 10.1038/ng.2610. Full text in Research Archive
• Ried-Larsen, Mathias; Grøntved, A.; Froberg, K.; Ekelund, Ulf & Andersen, Lars Bo (2013). Physical activity intensity and subclinical atherosclerosis in Danish adolescents: The European Youth Heart Study. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 23(3), p. e168–e177. doi: 10.1111/sms.12046. Full text in Research Archive Show summary

  The aim was to investigate the associations between physical activity (PA), cardiorespiratory fitness (CRF) and intima media thickness (IMT) or stiffness. This was a population-based cross-sectional study (n = 336) of Danish adolescents [mean age (standard deviation, SD): 15.6 (0.4) years]. PA intensity was assessed objectively (ActiGraph model GT3X) and CRF using a progressive maximal bicycle test. Carotid IMT and arterial stiffness were assessed using B-mode ultrasound. In a multivariate analysis (adjusted for pubertal development and smoking status), CRF was inversely associated with measures of carotid stiffness (standard beta: −0.20 to −0.15, P < 0.05) in boys, but not in girls. No associations were observed between any of PA and IMT. Boys in the least fit quartile had significantly stiffer carotid arteries compared to the most fit quartile (difference between lowest and highest quartile ranging between 0.4 and 0.5 SD, P < 0.05). This difference in arterial stiffness between low and high quartiles was similar for moderate-to-vigorous PA (MVPA). Further adjustment for sedentary time attenuated the difference observed between quartiles MVPA slightly. Adiposity did not attenuate these differences. Our observations suggest that increasing CRF or MVPA in the least active group of the population may be beneficial for vascular health.

• Harris, Tess; Kerry, Sally; Victor, Christina; Shah, Sunil M.; Iliffe, Steve & Ussher, Michael [Show all 19 contributors for this article] (2013). PACE-UP (Pedometer and consultation evaluation - UP) - a pedometer-based walking intervention with and without practice nurse support in primary care patients aged 45-75 years: study protocol for a randomised controlled trial. Trials. 14. doi: 10.1186/1745-6215-14-418. Full text in Research Archive
• Hoed, Marcel den; Brage, Søren; Zhao, Jing Hua; Westgate, Kate; Nessa, Ayrun & Ekelund, Ulf [Show all 9 contributors for this article] (2013). Heritability of objectively assessed daily physical activity and sedentary behavior. American Journal of Clinical Nutrition. ISSN 0002-9165. 98(5), p. 1317–1325. doi: 10.3945/ajcn.113.069849. Full text in Research Archive Show summary

  Background: Twin and family studies that estimated the heritability of daily physical activity have been limited by poor measurement quality and a small sample size. Objective: We examined the heritability of daily physical activity and sedentary behavior assessed objectively by using combined heart rate and movement sensing in a large twin study. Design: Physical activity traits were assessed in daily life for a mean (±SD) 6.7 ± 1.1 d in 1654 twins from 420 monozygotic and 352 dizygotic same-sex twin pairs aged 56.3 ± 10.4 y with body mass index (in kg/m2) of 26.1 ± 4.8. We estimated the average daily movement, physical activity energy expenditure, and time spent in moderate-to-vigorous intensity physical activity and sedentary behavior from heart rate and acceleration data. We used structural equation modeling to examine the contribution of additive genetic, shared environmental, and unique environmental factors to between-individual variation in traits. Results: Additive genetic factors (ie, heritability) explained 47% of the variance in physical activity energy expenditure (95% CI: 23%, 53%) and time spent in moderate-to-vigorous intensity physical activity (95% CI: 29%, 54%), 35% of the variance in acceleration of the trunk (95% CI: 0%, 44%), and 31% of the variance in the time spent in sedentary behavior (95% CI: 9%, 51%). The remaining variance was predominantly explained by unique environmental factors and random error, whereas shared environmental factors played only a marginal role for all traits with a range of 0–15%. Conclusions: The between-individual variation in daily physical activity and sedentary behavior is mainly a result of environmental influences. Nevertheless, genetic factors explain up to one-half of the variance, suggesting that innate biological processes may be driving some of our daily physical activity.

• Knowles, Gemma; Pallan, Miranda; Thomas, G. Neil; Ekelund, Ulf; Cheng, Kar Keung & Barrett, Timothy G [Show all 7 contributors for this article] (2013). Physical Activity and Blood Pressure in Primary School Children : A Longitudinal Study. Hypertension. ISSN 0194-911X. 61(1), p. 70–75. doi: 10.1161/HYPERTENSIONAHA.112.201277. Full text in Research Archive Show summary

  High blood pressure (BP) is becoming increasingly common during childhood. Regular physical activity (PA) reduces BP in adults, but limited studies have reported inconsistent results among children. The aim of this study is to examine, for the first time, the cross-sectional and longitudinal associations between BP and objectively measured PA in young children of predominantly South Asian background. Data from the Birmingham healthy Eating and Active lifestyle for CHildren Study were analyzed. Five hundred seventy-four children, aged 5 to 7 years, underwent a series of measures at baseline and were followed up 2 years later. PA was objectively measured using accelerometry and converted to counts per minute (total PA, cpm), and time spent in moderate-vigorous PA (minutes per day). BP was measured by trained staff using standard protocols. Data were available for 512 children at baseline (mean age 6.5 years, range 5.4–7.8 years), and 427 of these children were followed up. Baseline total PA was inversely associated with diastolic BP at both baseline (adjusted regression coefficient: −0.75 mm Hg [95% CI −1.33 to −0.18] per 20 cpm) and follow-up (−0.74 mm Hg [95% CI −1.40 to −0.08]). All associations remained unchanged after further adjustment for weight status. This study strengthens evidence of a causal association between higher PA and lower BP in children as young as 5, independent of weight status. The results provide support for development of interventions to increase PA in young children.

• Janssen, Xanne; Cliff, Dylan; Okely, Anthony D.; Jones, Rachel A.; Batterham, Marijka & Ekelund, Ulf [Show all 8 contributors for this article] (2013). Practical utility and reliability of whole-room calorimetry in young children. British Journal of Nutrition. ISSN 0007-1145. 109(10), p. 1917–1922. doi: 10.1017/S0007114512003820. Full text in Research Archive Show summary

  The use of whole-room calorimetry (WRC) in young children can increase our understanding of children's energy balance. However, studies using WRC in young children are rare due to concerns about its feasibility. To assess the feasibility of WRC in young children, forty children, aged 4–6 years, were asked to follow a graded activity protocol while in a WRC. In addition, six children participated in two additional resting protocols to examine the effect of diet-induced thermogenesis on resting energy expenditure (REE) measures and the reliability of REE measurement. Refusals to participate and data loss were quantified as measures of practical utility, and REE measured after an overnight fast and after a 90-min fast were compared. In addition, both were compared to predicted BMR values using the Schofield equation. Our results showed that thirty (78·9 %) participants had acceptable data for all intensities of the activity protocol. The REE values measured after a 90-min fast (5·07 (sd 1·04) MJ/d) and an overnight fast (4·73 (sd 0·61) MJ/d) were not significantly different from each other (P = 0·472). However, both REE after an overnight fast and a 90-min fast were significantly higher than predicted BMR (3·96 (sd 0·18) MJ/d) using the Schofield equation (P = 0·024 and 0·042, respectively). We conclude that, with a developmentally sensitive approach, WRC is feasible and can be standardised adequately even in 4- to 6-year-old children. In addition, the effect of a small standardised breakfast, approximately 90 min before REE measurements, is likely to be small.

• Ho, Vanda; Simmons, Rebecca K.; Ridgway, Charlotte L.; Sluijs, Esther M.F. van; Bamber, Diane J. & Goodyer, Ian M. [Show all 9 contributors for this article] (2013). Is wearing a pedometer associated with higher physical activity among adolescents? Preventive Medicine. ISSN 0091-7435. 56(5), p. 273–277. doi: 10.1016/j.ypmed.2013.01.015. Full text in Research Archive Show summary

  Objective: To examine whether wearing a pedometer was associated with higher objectively-measured physical activity (PA) among adolescents independent of other behavior change strategies, and whether this association differed by sex or day of wear. Method: In a parallel-group population-based cohort study, 892 adolescents (43.4% male, mean ± SD age, 14.5 ± 0.5 years) from Eastern England were recruited. PA was measured (in 2005–2006) by accelerometry over four days; a sub-group (n = 345) wore a pedometer coterminously with the accelerometer. Three-level (individual, day of wear and school level) multiple linear regression was used to examine the association between accelerometry (counts/min, cpm) and pedometer wear, stratified by sex and adjusted for weekday/weekend. Results: For the entire cohort, there was a significant decline in cpm over four days (p < 0.01). Girls wearing pedometers had higher mean cpm than those not wearing a pedometer, independent of BMI z-score, socio-economic status, weekday/weekend, and school clustering (β = 5.1; 95% CI: 0.8 to 9.5, p = 0.02). This association was not seen in boys. Conclusion: Pedometer wear was associated with higher PA among adolescent girls, but not boys. Findings may support sex-specific intervention strategies. In addition to pedometer monitoring, additional strategies may be required to promote PA levels, especially among boys.

• Kolle, Elin & Ekelund, Ulf (2013). Is Sitting Time a Strong Predictor of Weight Gain? Current Obesity Reports. 2(1), p. 77–85. doi: 10.1007/s13679-012-0039-2. Full text in Research Archive Show summary

  The current review aimed to examine the evidence on prospective associations between sedentary behavior (i.e., sitting time) and weight gain. Prospective studies published between January 2010 and August 2012 were identified from searches in the Medline databases. In total 13 studies (seven in adolescents and six in adults) examining the prospective association between sedentary behavior and any measure of weight gain met inclusion criteria. In adolescents, mixed evidence was observed for a positive association between sedentary behavior at baseline and weight gain at follow-up. In adults, there was insufficient evidence that sedentary time at baseline was a strong predictor of weight gain at follow-up. The majority of the included studies used self- or parent-reported sedentary time which can be affected by social desirability and recall bias. Marked heterogeneity in study populations, exposure and outcome measures precluded a quantitative meta-analysis. Failure to appropriately adjust the results for baseline measures of the outcome particularly in the studies in children and adolescents may partly explain the observations. Therefore, firm conclusions whether prolonged sitting time predict weight gain in young people and adults is currently not possible. High-quality studies using repeated objective measures of sedentary behavior is warranted to establish a causal association.

• Sluijs, Esther M.F. van; McMinn, Alison M.; Inskip, Hazel M.; Ekelund, Ulf; Godfrey, Keith M. & Harvey, Nicholas C. [Show all 7 contributors for this article] (2013). Correlates of light and moderate-to-vigorous objectively measured physical activity in four-year old children. PLOS ONE. 8(9:74934). doi: 10.1371/journal.pone.0074934. Full text in Research Archive Show summary

  Background: Correlates of physical activity (PA) are hypothesized to be context and behaviour specific, but there is limited evidence of this in young children. The aim of the current study is to investigate associations between personal, social and environmental factors and objectively measured light and moderate-to-vigorous PA (LPA and MVPA, respectively) in four-year-old children. Methods: Cross-sectional data were used from the Southampton Women’s Survey, a UK population-based longitudinal study. Four-year old children (n = 487, 47.0% male) had valid PA data assessed using accelerometry (Actiheart) and exposure data collected with a validated maternal questionnaire (including data on child personality, family demographics, maternal behaviour, rules and restrictions, and perceived local environment). Linear regression modelling was used to analyse associations with LPA and MVPA separately, interactions with sex were explored. Results: LPA minutes were greater in children whose mothers reported more PA (vs. inactive: regression coefficient±standard error: 6.70±2.94 minutes), and without other children in the neighbourhood to play with (−6.33±2.44). MVPA minutes were greater in children with older siblings (vs. none: 5.81±2.80) and those whose mothers used active transport for short trips (vs. inactive: 6.24±2.95). Children accumulated more MVPA in spring (vs. winter: 9.50±4.03) and, in boys only, less MVPA with availability of other children in the neighbourhood (−3.98±1.70). Discussion: Young children’s LPA and MVPA have differing associations with a number of social and environmental variables. Interventions targeting PA promotion in young children outside of formal care settings should consider including intensity specific factors.

• Atkin, Andrew J.; Corder, Kirsten; Ekelund, Ulf; Wijndaele, Katrien; Griffin, Simon J. & Sluijs, Esther M.F. van (2013). Determinants of Change in Children's Sedentary Time. PLOS ONE. 8(6). doi: 10.1371/journal.pone.0067627. Full text in Research Archive Show summary

  Background: Understanding the determinants of sedentary time during childhood contributes to the development of effective intervention programmes. Purpose: To examine family and home-environmental determinants of 1-year change in objectively measured sedentary time after-school and at the weekend. Methods: Participants wore accelerometers at baseline and 1 year later. Longitudinal data for after-school and weekend analyses were available for 854 (41.5%male, mean±SD age 10.2±0.3years) and 718 (41.8%male, age 10.2±0.3years) participants. Information on 26 candidate determinants, including socioeconomic status (SES), availability of electronic media and parental rules for sedentary behaviours was self-reported by children or their parents at baseline. Change in the proportion of registered time spent sedentary was used as the outcome variable in multi-level linear regression models, adjusted for age, sex, body mass index and baseline sedentary time. Simple and multiple models were run and interactions with sex explored. Results: Children from higher socioeconomic status families exhibited greater increases in after-school (beta; 95% CI for change in % time spent sedentary 1.02; 0.37, 1.66) and weekend (1.42; 0.65, 2.18) sedentary time. Smaller increases in after-school sedentary time were observed in children with more siblings (−1.00; −1.69, −0.30), greater availability of electronic media (−0.81; −1.29, −0.33) and, for boys, more frequent family visits to the park (−1.89; −3.28, −0.51) and family participation in sport (−1.28; −2.54, −0.02). Greater maternal weekend screen-time (0.45; 0.08, 0.83) and, in girls, greater parental restriction on playing outside (0.91; 0.08, 1.74) were associated with larger increases in weekend sedentary time. The analytical sample was younger, more likely to be female, had lower BMI and was of higher SES than the original baseline sample. Conclusions: Intervention strategies aimed at reducing parents’ weekend screen-time, increasing family participation in sports or recreation (boys) and promoting freedom to play outside (girls) may contribute towards preventing the age-related increase in sedentary time.

• Brooke, Hannah L.; Corder, Kirsten; Griffin, Simon J.; Ekelund, Ulf & Sluijs, Esther M.F. van (2013). More of the same or a change of scenery: an observational study of variety and frequency of physical activity in British children. BMC Public Health. 13. doi: 10.1186/1471-2458-13-761. Full text in Research Archive Show summary

  Background: Physical activity is important for children’s health, but successful physical activity promotion is challenging. Whether performing many different types of activities (Variety) is associated with higher physical activity independent of the number of activity sessions (Frequency) is unknown, but this information could inform physical activity promotion and public health strategies in children. Methods: In the SPEEDY study we measured moderate-to-vigorous intensity physical activity (MVPA; ≥2000 counts/minute) over 7 days using GT1M Actigraph accelerometers in 1700 children from Norfolk, UK (56% girls, Mean ± SD 10.3 ± 0.3 years-old). Children reported participation in 28 leisure-time activities over the previous 7 days. Sex differences in activity participation were assessed using multilevel logistic regression, clustered by school. Associations of log-transformed MVPA with z-score-Variety (number of different activities/week) and z-score-Frequency (sum of all activity sessions/week) were examined using multilevel linear regression, adjusted for age, sex, parental education and age-standardised BMI. Results: Children’s activity participation often reflected gender stereotypes. Mean ± SD Variety was 10.8 ± 5.0 activities/week, and Frequency was 24.2±15.0 sessions/week. In separate models lnMVPA had similar strength, positive associations with z-score-Variety and z-score-Frequency (Exp β(95% CI); Variety 1.04(1.02-1.06), Frequency 1.04(1.02-1.06)). lnMVPA was not associated with z-score-Variety independent of z-score-Frequency (Variety 1.01(0.98-1.04), Frequency 1.03(1.00-1.06)). Conclusions: Future physical activity interventions and public health strategies could allow for gender specific activity preferences and could target both Variety and Frequency of activities participated in by children.

• Hees, Vincent T. van; Gorzelniak, Lukas; Leon, Emmanuel Carlos Dean; Eder, Martin; Pias, Marcelo & Taherian, Salman [Show all 11 contributors for this article] (2013). Separating Movement and Gravity Components in an Acceleration Signal and Implications for the Assessment of Human Daily Physical Activity. PLOS ONE. 8(4). doi: 10.1371/journal.pone.0061691. Full text in Research Archive Show summary

  Introduction: Human body acceleration is often used as an indicator of daily physical activity in epidemiological research. Raw acceleration signals contain three basic components: movement, gravity, and noise. Separation of these becomes increasingly difficult during rotational movements. We aimed to evaluate five different methods (metrics) of processing acceleration signals on their ability to remove the gravitational component of acceleration during standardised mechanical movements and the implications for human daily physical activity assessment. Methods: An industrial robot rotated accelerometers in the vertical plane. Radius, frequency, and angular range of motion were systematically varied. Three metrics (Euclidian norm minus one [ENMO], Euclidian norm of the high-pass filtered signals [HFEN], and HFEN plus Euclidean norm of low-pass filtered signals minus 1 g [HFEN+]) were derived for each experimental condition and compared against the reference acceleration (forward kinematics) of the robot arm. We then compared metrics derived from human acceleration signals from the wrist and hip in 97 adults (22–65 yr), and wrist in 63 women (20–35 yr) in whom daily activity-related energy expenditure (PAEE) was available. Results: In the robot experiment, HFEN+ had lowest error during (vertical plane) rotations at an oscillating frequency higher than the filter cut-off frequency while for lower frequencies ENMO performed better. In the human experiments, metrics HFEN and ENMO on hip were most discrepant (within- and between-individual explained variance of 0.90 and 0.46, respectively). ENMO, HFEN and HFEN+ explained 34%, 30% and 36% of the variance in daily PAEE, respectively, compared to 26% for a metric which did not attempt to remove the gravitational component (metric EN). Conclusion: In conclusion, none of the metrics as evaluated systematically outperformed all other metrics across a wide range of standardised kinematic conditions. However, choice of metric explains different degrees of variance in daily human physical activity.

• Collings, Paul J.; Brage, Søren; Ridgway, Charlotte L.; Harvey, Nicholas C.; Godfrey, Keith M. & Inskip, Hazel M. [Show all 9 contributors for this article] (2013). Physical activity intensity, sedentary time, and body composition in preschoolers. American Journal of Clinical Nutrition. ISSN 0002-9165. 97(5), p. 1020–1028. doi: 10.3945/ajcn.112.045088. Full text in Research Archive Show summary

  Background: Detailed associations between physical activity (PA) subcomponents, sedentary time, and body composition in preschoolers remain unclear. Objective: We examined the magnitude of associations between objectively measured PA subcomponents and sedentary time with body composition in 4-y-old children. Design: We conducted a cross-sectional study in 398 preschool children recruited from the Southampton Women’s Survey. PA was measured by using accelerometry, and body composition was measured by using dual-energy X-ray absorptiometry. Associations between light physical activity, moderate physical activity (MPA), vigorous physical activity (VPA), and moderate-to-vigorous physical activity (MVPA) intensity; sedentary time; and body composition were analyzed by using repeated-measures linear regression with adjustment for age, sex, birth weight, maternal education, maternal BMI, smoking during pregnancy, and sleep duration. Sedentary time and PA were also mutually adjusted for one another to determine whether they were independently related to adiposity. Results: VPA was the only intensity of PA to exhibit strong inverse associations with both total adiposity [P , 0.001 for percentage of body fat and fat mass index (FMI)] and abdominal adiposity (P = 0.002 for trunk FMI). MVPA was inversely associated with total adiposity (P = 0.018 for percentage of body fat; P = 0.022 for FMI) but only because of the contribution of VPA, because MPA was unrelated to fatness (P $ 0.077). No associations were shown between the time spent sedentary and body composition (P $ 0.11). Conclusions: In preschoolers, the time spent in VPA is strongly and independently associated with lower adiposity. In contrast, the time spent sedentary and in low-to-moderate–intensity PA was unrelated to adiposity. These results indicate that efforts to challenge pediatric obesity may benefit from prioritizing VPA.

• Janssen, Xanne; Cliff, Dylan P.; Reilly, John J.; Hinkley, Trina; Jones, Rachel A. & Batterham, Marijka [Show all 9 contributors for this article] (2013). Predictive validity and classification accuracy of actigraph energy expenditure equations and cut-points in young children. PLOS ONE. 8(11:e79124). doi: 10.1371/journal.pone.0079124. Full text in Research Archive Show summary

  Objectives: Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers. Methods: Forty children aged 4–6 years (5.3±1.0 years) completed a ~150-min room calorimeter protocol involving age-appropriate sedentary, light and moderate-to vigorous-intensity physical activities. Children wore an ActiGraph GT3X on the right mid-axillary line of the hip. Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods. Energy expenditure was predicted using Pate and Puyau equations. Physical activity intensity was classified using Evenson, Sirard, Van Cauwenberghe, Pate, Puyau, and Reilly, ActiGraph cut-points. Results: The Pate equation significantly overestimated VO2 during sedentary behaviors, light physical activities and total VO2 (P<0.001). No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities (P = 0.072). The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities, light-intensity physical activities and total activity energy expenditure (P<0.0125). However, no overestimation of activity energy expenditure during sedentary behavior was found. The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others. Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others. Conclusion: Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers. Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities, respectively, are recommended.

• Corder, Kirsten; Craggs, Christopher; Jones, Andrew P.; Ekelund, Ulf; Griffin, Simon J. & Sluijs, Esther M.F. van (2013). Predictors of change differ for moderate and vigorous intensity physical activity and for weekdays and weekends: a longitudinal analysis. International Journal of Behavioral Nutrition and Physical Activity. 10. doi: 10.1186/1479-5868-10-69. Full text in Research Archive Show summary

  Background Predictors of physical activity (PA) change are rarely investigated separately for different PA intensities and for weekdays/weekends. We investigated whether individual-level predictors of one-year change in objectively-measured physical activity differ for moderate PA (MPA) and vigorous PA (VPA) and for weekends and weekdays. Methods Accelerometer-assessed PA (mins) was obtained at baseline and +1 year (n = 875, 41.5% male, Mean ± SD baseline age: 9.8 ± 0.4 years-old). Potential predictors (n = 38) were assessed at baseline from psychological (e.g. self-efficacy), socio-cultural (e.g. parent support) and environmental domains (e.g. land use). Associations between predictors and change in MPA (2000–3999 counts/minute (cpm)) and VPA (≥4000 cpm) separately for weekdays and weekends were studied using multi-level linear regression. Analyses were adjusted for school clustering, sex and baseline PA. Results Weekend PA declined (MPA decline 4.6 ± 21.8 mins/day; VPA decline: 2.1 ± 20.1 mins/day; both p < 0.001) whereas weekday PA did not significantly change. Higher baseline PA and being a girl were associated with greater PA declines in all four outcomes; remaining predictors differed for MPA and VPA and/or weekdays and weekends. Family logistic support was associated with less of a decline in weekend MPA (CI 95%) 0.15 (0.05, 0.25) and VPA 0.19 (0.09, 0.29), and peer support with less of a decline in weekday MPA 0.18 (0.02, 0.34) and VPA 0.22 (0.06, 0.38). Conclusions Results highlight the relevance of investigating predictors of PA change separately for different PA intensities and for weekdays/weekends. In addition to continued focus on school PA promotion, more effort to target interventions during weekends, such as in the family and community appears important. Encouraging peer support to increase weekday PA and targeting parent support for weekend PA may be health promotion priorities.

• Corder, Kirsten; Atkin, Andrew J.; Ekelund, Ulf & Sluijs, Esther M.F. van (2013). What do adolescents want in order to become more active? BMC Public Health. 13. doi: 10.1186/1471-2458-13-718. Full text in Research Archive Show summary

  Background: Few large studies have examined adolescents’ views about increasing their physical activity (PA) to inform PA promotion. We assessed adolescent preference for activity type, co-participants, timing and location of PA promotion and examined patterns in their views by population subgroup. Methods: Participants (n = 457) (Mean ± SD age: 14.3 ± 0.3 years; 45.2% male) responded to questionnaire items: “What activities would you like to try or do more often?” (yes/no to 6 activity types e.g. team sports) and “I would like to do more PA …” followed by options regarding co-participants, timing and PA location (agree/disagree to 10 items). Anthropometry, demographics, accelerometer- and questionnaire-derived PA were obtained. Logistic regression was used to examine differences in views by subgroup (sex, weight status, objective PA level, parental education (SES)). Results: Most adolescents wanted to increase participation in ≥1 type of PA (94.4%). Gym use (56.7%) and team sports (50.6%) were most popular. Girls were less likely to choose racquet sports (vs. boys OR; 95% CI 0.6;0.4-0.9) but more likely to select dancing (40.3;17.8-91.1). Preference for participation was positively associated with existing participation in a similar activity (all p < 0.02). More adolescents wanted to increase PA with friends (88.8%) than family (63.5%). A leisure centre was most popular for increased participation (81.0%), followed by home (70.0%). Participation during school time was less popular among girls (vs. boys: 0.6;0.4-0.9) and more popular among low SES participants (vs. high: 1.6;1.1-2.4). Overweight/obese adolescents were less likely to choose participation with friends (vs. normal weight 0.5;0.3-0.9). Conclusions: Targeting adolescent PA promotion by subgroup and providing choice of PA type, co-participants, timing and PA location appears promising. Adolescents want to do more types of PA more often; interventions could increase opportunities and support to facilitate this.

• Grøntved, Anders; Ried-Larsen, Mathias; Ekelund, Ulf; Froberg, Karsten; Brage, Søren Karl & Andersen, Lars Bo (2013). Independent and Combined Association of Muscle Strength and Cardiorespiratory Fitness in Youth With Insulin Resistance and -Cell Function in Young Adulthood: The European Youth Heart Study. Diabetes Care. ISSN 0149-5992. 36(9), p. 2575–2581. doi: 10.2337/dc12-2252. Full text in Research Archive Show summary

  OBJECTIVE: To examine the independent and combined association of isometric muscle strength of the abdomen and back and cardiorespiratory fitness (CRF) in youth with indices of glucose metabolism in young adulthood among boys and girls from the European Youth Heart Study. RESEARCH DESIGN AND METHODS: We used data from a population-based prospective cohort study among youth followed up for up to 12 years (n = 317). In youth, maximal voluntary contractions during isometric back extension and abdominal flexion were determined using a strain-gauge dynamometer and CRF was obtained from a maximal cycle ergometer test. Insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) and β-cell function (homeostasis model assessment of β-cell function [HOMA-B]) were estimated from fasting serum insulin and glucose that were obtained in youth and at follow-up in young adulthood. RESULTS: For each 1-SD difference in isometric muscle strength (0.16 N/kg) in youth, fasting insulin, HOMA-IR, and HOMA-B in young adulthood changed by −11.3% (95% CI −17.0 to −5.2), −12.2% (−18.2 to −5.7), and −8.9% (−14.4 to −3.0), respectively, in young adulthood after adjustment for CRF and personal lifestyle and demographic factors. Results for CRF were very similar in magnitude, and the magnitude of associations for both exposures was unchanged with additional adjustment for general or abdominal adiposity in youth. Combined associations of muscle strength and CRF with fasting insulin, HOMA-IR, and HOMA-B were additive, and adolescents in the highest sex-specific tertile for both isometric muscle strength and CRF had the lowest levels of these glucose metabolism outcomes. CONCLUSIONS: Increasing muscle strength and CRF should be targets in youth primordial prevention strategies of insulin resistance and β-cell dysfunction.

• Atkin, Andrew J.; Ekelund, Ulf; Møller, Niels Christian; Froberg, Karsten; Sardinha, Luis B. & Andersen, Lars Bo [Show all 7 contributors for this article] (2013). Sedentary time in children: influence of accelerometer processing on health relations. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 45(6), p. 1097–1104. doi: 10.1249/MSS.0b013e318282190e. Full text in Research Archive Show summary

  Purpose: Accelerometry is increasingly being used to assess sedentary time in epidemiological studies, yet the most appropriate means of processing these data remains uncertain. This cross-sectional study examined the influence of selected accelerometer cut points and nonwear criteria on associations of sedentary time with adiposity and clustered metabolic risk. Methods: Data were from the European Youth Heart Study, which included assessment of sedentary time by accelerometer. Sixteen sedentary time variables were constructed based on combinations of frequently used cut points (100, 500, 800, and 1100 counts per minute) and nonwear criteria (10-, 20-, 60-, and 100-min consecutive zeros). Adiposity was assessed by sum of four skinfold thickness measures. A clustered metabolic risk score was calculated as the mean of standardized metabolic syndrome components, including blood pressure, insulin resistance, and inverted fasting HDL-cholesterol. Analyses were conducted using multilevel cross-sectional time series regression, adjusted for overall physical activity (accelerometer counts per minute). Meta-analysis was used to obtain pooled estimates of the exposure–outcome association over all processing protocols; meta-regression was used to determine the influence of nonwear and cut point protocol on observed associations. Results: Sedentary time follows a power law with cut point (exponent = 0.27) and zero string (exponent = 0.03), and it was positively associated with clustered metabolic risk ([beta] = 0.0051; 95% confidence interval = 0.0018–0.0085). The association was moderated by cut point, with higher cut points typically producing stronger associations. No significant association between sedentary time and adiposity was observed. Conclusions: The choice of accelerometer cut point may moderate the association between sedentary time and clustered metabolic risk, suggesting that direct comparisons of associations between studies using different cut points must be made with caution.

• Rohrmann, Sabine; Steinbrecher, Astrid; Linseisen, Jakob; Hermann, Silke; May, Anne M. & Luan, Jian'an [Show all 48 contributors for this article] (2012). The association of education with long-term weight change in the EPIC-PANACEA cohort. European Journal of Clinical Nutrition. ISSN 0954-3007. 66(8), p. 957–963. doi: 10.1038/ejcn.2012.55. Full text in Research Archive
• Peters, Tricia; Brage, Søren; Westgate, Kate; Franks, Paul W.; Gradmark, Anna & Diaz, Maria Jose Tormo [Show all 42 contributors for this article] (2012). Validity of a short questionnaire to assess physical activity in 10 European countries. European Journal of Epidemiology (EJE). ISSN 0393-2990. 27(1), p. 15–25. doi: 10.1007/s10654-011-9625-y. Full text in Research Archive
• Hallal, Pedro C.; Andersen, Lars Bo; Bull, Fiona; Guthold, Regina; Haskell, William & Ekelund, Ulf (2012). Global physical activity levels: surveillance progress, pitfalls, and prospects. The Lancet. ISSN 0140-6736. 380(9838), p. 247–257. doi: 10.1016/S0140-6736(12)60646-1. Full text in Research Archive Show summary

  To implement effective non-communicable disease prevention programmes, policy makers need data for physical activity levels and trends. In this report, we describe physical activity levels worldwide with data for adults (15 years or older) from 122 countries and for adolescents (13–15-years-old) from 105 countries. Worldwide, 31·1% (95% CI 30·9–31·2) of adults are physically inactive, with proportions ranging from 17·0% (16·8–17·2) in southeast Asia to about 43% in the Americas and the eastern Mediterranean. Inactivity rises with age, is higher in women than in men, and is increased in high-income countries. The proportion of 13–15-year-olds doing fewer than 60 min of physical activity of moderate to vigorous intensity per day is 80·3% (80·1–80·5); boys are more active than are girls. Continued improvement in monitoring of physical activity would help to guide development of policies and programmes to increase activity levels and to reduce the burden of non-communicable diseases.

• Helmerhorst, Henrik J.F.; Brage, Søren; Warren, Janet; Besson, Herve & Ekelund, Ulf (2012). A systematic review of reliability and objective criterion-related validity of physical activity questionnaires. International Journal of Behavioral Nutrition and Physical Activity. 9. doi: 10.1186/1479-5868-9-103. Full text in Research Archive Show summary

  Physical inactivity is one of the four leading risk factors for global mortality. Accurate measurement of physical activity (PA) and in particular by physical activity questionnaires (PAQs) remains a challenge. The aim of this paper is to provide an updated systematic review of the reliability and validity characteristics of existing and more recently developed PAQs and to quantitatively compare the performance between existing and newly developed PAQs.A literature search of electronic databases was performed for studies assessing reliability and validity data of PAQs using an objective criterion measurement of PA between January 1997 and December 2011. Articles meeting the inclusion criteria were screened and data were extracted to provide a systematic overview of measurement properties. Due to differences in reported outcomes and criterion methods a quantitative meta-analysis was not possible.In total, 31 studies testing 34 newly developed PAQs, and 65 studies examining 96 existing PAQs were included. Very few PAQs showed good results on both reliability and validity. Median reliability correlation coefficients were 0.62--0.71 for existing, and 0.74--0.76 for new PAQs. Median validity coefficients ranged from 0.30--0.39 for existing, and from 0.25--0.41 for new PAQs.Although the majority of PAQs appear to have acceptable reliability, the validity is moderate at best. Newly developed PAQs do not appear to perform substantially better than existing PAQs in terms of reliability and validity. Future PAQ studies should include measures of absolute validity and the error structure of the instrument.

• May, Anne M.; Adema, Lotte E.; Romaguera, Dora; Vergnaud, Anne-Claire; Agudo, Antonio & Ekelund, Ulf [Show all 46 contributors for this article] (2012). Determinants of non- response to a second assessment of lifestyle factors and body weight in the EPIC-PANACEA study. BMC Medical Research Methodology. 12. doi: 10.1186/1471-2288-12-148. Full text in Research Archive Show summary

  This paper discusses whether baseline demographic, socio-economic, health variables, length of follow-up and method of contacting the participants predict non-response to the invitation for a second assessment of lifestyle factors and body weight in the European multi-center EPIC-PANACEA study. Over 500.000 participants from several centers in ten European countries recruited between 1992 and 2000 were contacted 2–11 years later to update data on lifestyle and body weight. Length of follow-up as well as the method of approaching differed between the collaborating study centers. Non-responders were compared with responders using multivariate logistic regression analyses. Overall response for the second assessment was high (81.6%). Compared to postal surveys, centers where the participants completed the questionnaire by phone attained a higher response. Response was also high in centers with a short follow-up period. Non-response was higher in participants who were male (odds ratio 1.09 (confidence interval 1.07; 1.11), aged under 40 years (1.96 (1.90; 2.02), living alone (1.40 (1.37; 1.43), less educated (1.35 (1.12; 1.19), of poorer health (1.33 (1.27; 1.39), reporting an unhealthy lifestyle and who had either a low (<18.5 kg/m2, 1.16 (1.09; 1.23)) or a high BMI (>25, 1.08 (1.06; 1.10); especially ≥30 kg/m2, 1.26 (1.23; 1.29)). Cohort studies may enhance cohort maintenance by paying particular attention to the subgroups that are most unlikely to respond and by an active recruitment strategy using telephone interviews.

• May, Anne M.; Romaguera, Dora; Travier, Noémie; Ekelund, Ulf; Bergmann, Manuela M. & Kaaks, Rudolf [Show all 44 contributors for this article] (2012). Combined Impact of Lifestyle Factors on Prospective Change in Body Weight and Waist Circumference in Participants of the EPIC-PANACEA Study. PLOS ONE. 7(11). doi: 10.1371/journal.pone.0050712. Full text in Research Archive Show summary

  The evidence that individual dietary and lifestyle factors influence a person’s weight and waist circumference is well established; however their combined impact is less well documented. Therefore, we investigated the combined effect of physical activity, nutrition and smoking status on prospective gain in body weight and waist circumference. We used data of the prospective EPIC-PANACEA study. Between 1992 and 2000, 325,537 participants (94,445 men and 231,092 women, aged between 25–70) were recruited from nine European countries. Participants were categorised into two groups (positive or negative health behaviours) for each of the following being physically active, adherent to a healthy (Mediterranean not including alcohol) diet, and never-smoking for a total score ranging from zero to three. Anthropometric measures were taken at baseline and were mainly self-reported after a medium follow-up time of 5 years. Mixed-effects linear regression models adjusted for age, educational level, alcohol consumption, baseline body mass index and follow-up time showed that men and women who reported to be physically active, never-smoking and adherent to the Mediterranean diet gained over a 5-year period 537 (95% CI −706, −368) and 200 (−478, −87) gram less weight and 0.95 (−1.27, −0.639) and 0.99 (−1.29, −0.69) cm less waist circumference, respectively, compared to participants with zero healthy behaviours. The combination of positive health behaviours was associated with significantly lower weight and waist circumference gain

• Reichert, Felipe F.; Hallal, Pedro C.; Wells, Jonathan; Horta, Bernardo L.; Ekelund, Ulf & Menezes, Ana MB (2012). Objectively Measured Physical Activity in the 1993 Pelotas (Brazil) Birth Cohort. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 44(12), p. 2369–2375. doi: 10.1249/MSS.0b013e3182687d35. Full text in Research Archive Show summary

  Introduction: Data on physical activity levels of adolescents are mostly derived from self-reported instruments, and the vast majority of studies using objective measures are from high-income countries. The aim of this study was to describe the patterns of objectively measured physical activity in Brazilian adolescents. Methods: In 2004–2005 (mean age of 13.3 yr), a subsample of the 1993 Pelotas (Brazil) Birth Cohort with data on all previous visits was approached. Physical activity was measured using the ActiGraph GT1M accelerometer (ActiGraph Corporation, Pensacola, FL). Demographic and other variables were assessed by self-report. Results: A total of 486 individuals (51% boys) provided valid data on objectively measured physical activity (response rate = 95.1%). The mean registered time of accelerometer data was 1191 min·d-1 (SD = 112). The mean times (in minutes) spent in sedentary, light, moderate, and vigorous activities were 962 (SD = 114), 176 (SD = 46), 36 (SD = 16), and 17 (SD = 10) min·d-1, respectively. More than 30% of the adolescents accumulated >=60 min·d-1 of moderate-to-vigorous physical activity (MVPA). Physical activity intensity (counts per minute) and the prevalence of accumulation >=60 min·d-1 of MVPA were higher among boys and in those who walked or cycled to school. The prevalence of accumulation >60 min·d-1 of MVPA was 125% higher in those from lower economic levels compared with higher economic levels (P < 0.001). Conclusion: A large proportion of Brazilian adolescents of the 1993 Pelotas Birth Cohort do not achieve the current recommendation for health-related physical activity, and active commuting to school may be a target for interventions aimed at increasing physical activity. Physical activity levels are higher in lower socioeconomic groups than that in higher groups.

• Kwon, Soyang; Janz, Kathleen F.; Cooper, Ashley R.; Ekelund, Ulf; Esliger, Dale W. & Griew, Pippa [Show all 11 contributors for this article] (2012). Tracking of accelerometry-measured physical activity during childhood: ICAD pooled analysis. International Journal of Behavioral Nutrition and Physical Activity. 9. doi: 10.1186/1479-5868-9-68. Full text in Research Archive Show summary

  Background: Understanding of physical activity (PA) tracking during childhood is important to predict PA behaviors and design appropriate interventions. We compared tracking of PA according to PA level and type of day (weekday/weekend) in a pool of five children’s cohort studies. Methods: Data from ALSPAC, CLAN, Iowa Bone Development Study, HEAPS, PEACH were extracted from the International Children’s Accelerometry Database (ICAD), resulting in 5,016 participants with age, gender, and accelerometry data at both baseline and follow-up (mean age: 10.3 years at baseline, 12.5 years at follow-up). Daily minutes spent in moderate- and vigorous-intensity PA (MVPA) and vigorous-intensity PA (VPA) was categorized into quintiles. Multinomial logistic regression models were fit to predict follow-up (M)VPA from baseline (M)VPA (reference: 20-<80%tile), age at follow-up, and follow-up duration. Results: For the weekday, VPA tracking for boys with high baseline VPA was higher than boys with low baseline VPA (ORs: 3.9 [95% CI: 3.1, 5.0] vs. 2.1 [95% CI: 1.6, 2.6]). Among girls, high VPA was less stable when compared low VPA (ORs: 1.8 [95% CI: 1.4, 2.2] vs. 2.6 [95% CI: 2.1, 3.2]). The pattern was similar for MVPA among girls (ORs: 1.6 [95% CI: 1.2, 2.0] vs. 2.8 [95% CI: 2.3, 3.6]). Overall, tracking was lower for the weekend. Conclusions: PA tracking was higher on the weekday than the weekend, and among inactive girls than active girls. The PA “routine” of weekdays should be used to help children establish healthy PA patterns. Supports for PA increase and maintenance of girls are needed.

• Sundberg, F.; Forsander, G.; Fasth, A. & Ekelund, Ulf (2012). Children younger than 7 years with type 1 diabetes are less physically active than healthy controls. Acta Paediatrica. ISSN 0803-5253. 101(11), p. 1164–1169. doi: 10.1111/j.1651-2227.2012.02803.x. Full text in Research Archive Show summary

  Aim:  To examine if children younger than 7 years with type 1 diabetes are less physically active and spend more time sedentary than healthy children. Methods:  Using a repeated measures case-control study design, physical activity (PA) was measured by continuous combined accelerometer and heart rate registration for 7 days at two time points during 1 year (autumn and spring). PA data were expressed as time spent sedentary, in moderate and vigorous intensity PA and total PA. Differences between groups and gender were analysed with mixed linear regression models. In this study there were 24 children (12 girls) with type 1 diabetes mellitus and 26 (14 girls) healthy controls, all younger than 7 years at inclusion. Results:  Children with diabetes were less active overall (p = 0.010) and spent 16 min less in moderate-to-vigorous PA (p = 0.006). The difference in sedentary time (21 min less) between groups was not significant (p = 0.21). Overall PA (12.1 counts/min per day, p = 0.004) and time in moderate and vigorous PA (16.0 min/day, p = 0.002) was significantly higher in boys than in girls. A significant effect of age was observed. Conclusion:  Physical activity is significantly reduced in young children with type 1 diabetes.

• Wells, Jonathan; Dumith, Samuel C.; Ekelund, Ulf; Reichert, Felipe F.; Menezes, Ana MB & Victora, Cesar G. [Show all 7 contributors for this article] (2012). Associations of Intrauterine and Postnatal Weight and Length Gains With Adolescent Body Composition: Prospective Birth Cohort Study From Brazil. Journal of Adolescent Health. ISSN 1054-139X. 51(6), p. s58–s64. doi: 10.1016/j.jadohealth.2012.08.013. Full text in Research Archive Show summary

  Purpose: Early growth patterns have been associated with subsequent obesity risk. However, findings from middle-income populations suggest that early infant growth may benefit lean mass and height rather than adiposity. We tested the hypothesis that rapid weight or length gain in different growth periods would be associated with size and body composition in adolescence, in a prospective birth cohort from southern Brazil. Methods: Body composition was assessed in 425 adolescents (52.2% male) at 14 years. Exposures were birth weight z-score and conditional growth in weight or length for the periods 0–6, 6–12 and 12–48 months. Differences in anthropometric and body composition outcomes between tertiles of growth in each period were tested by one-way analysis of variance. Results: Size at birth and conditional weight and length at 6 months were associated with later height. The effect of infant weight gain on lean mass was greater for males than females, and effect on fat mass greater for females than males. By early childhood, rapid weight gain generated relatively similar effects on both tissue masses in both sexes. Rapid length gain had stronger effects on outcomes in males than females at each time point, and benefited lean mass more than adiposity. All effects were substantially attenuated after adjusting for current height. Early weight gain was more important than length gain at influencing body composition outcomes in adolescence. Conclusions: Rapid infant weight and length gains were primarily associated with larger size in adolescence rather than increased adiposity. From one year onwards, associations between rapid weight gain and fat and lean masses remained after adjustment for height.

• Borch, Kristin Benjaminsen; Ekelund, Ulf; Brage, Søren & Lund, Eiliv (2012). Criterion validity of a 10-category scale for ranking physical activity in Norwegian women. International Journal of Behavioral Nutrition and Physical Activity. 9. doi: 10.1186/1479-5868-9-2. Full text in Research Archive Show summary

  Accurate measurement of physical activity (PA) is critical to establish dose-response relationships with various health outcomes. We compared the self-administered PA questionnaire from the Norwegian Women and Cancer Study (NOWAC) with a criterion method in middle-aged Norwegian women. A sample of 177 randomly recruited healthy women attended two clinical visits approximately 4-6 months apart. At each visit, the women completed the NOWAC PA questionnaire (NOPAQ), rating their overall PA level on a 10-category scale (1 being a "very low" and 10 being a "very high" PA level) and performed an 8-minute step-test to estimate aerobic fitness (VO2max). After each visit, the women wore a combined heart rate and movement sensor for 4 consecutive days of free-living. Measures of PA obtained from the combined heart rate and movement sensor, which were used as criterion, included individually calibrated PA energy expenditure (PAEE), acceleration, and hours/day of moderate-to-vigorous intensity PA (MVPA). These were averaged between visits and compared to NOPAQ scores at visit 2. Intra-class correlation coefficients for objective measures from both free-living periods were in the range of 0.65-0.87 (P < 0.001), compared to 0.62 (P < 0.001) for NOPAQ. There was a moderate but significant (P < 0.001) Spearman's rank correlation coefficient in the range of 0.36-0.46 between NOPAQ and objective measures of PA. Linear trends for the association between the NOPAQ rating scale with PAEE, hours/day of MVPA and VO2max (P < 0.001) were also demonstrated. Self-reported PA level measured on a 10-category scale appears valid to rank PA in a female Norwegian population.

• Ekelund, Ulf; Luan, Jian'an; Sherar, Lauren; Esliger, Dale W.; Griew, Pippa & Cooper, Ashley R. (2012). Moderate to Vigorous Physical Activity and Sedentary Time and Cardiometabolic Risk Factors in Children and Adolescents. Journal of the American Medical Association (JAMA). ISSN 0098-7484. 307(7), p. 704–712. doi: 10.1001/jama.2012.156. Full text in Research Archive Show summary

  Context: Sparse data exist on the combined associations between physical activity and sedentary time with cardiometabolic risk factors in healthy children. Objective: To examine the independent and combined associations between objectively measured time in moderate- to vigorous-intensity physical activity (MVPA) and sedentary time with cardiometabolic risk factors. Design, Setting, and Participants: Pooled data from 14 studies between 1998 and 2009 comprising 20 871 children (aged 4-18 years) from the International Children's Accelerometry Database. Time spent in MVPA and sedentary time were measured using accelerometry after reanalyzing raw data. The independent associations between time in MVPA and sedentary time, with outcomes, were examined using meta-analysis. Participants were stratified by tertiles of MVPA and sedentary time. Main Outcome Measures: Waist circumference, systolic blood pressure, fasting triglycerides, high-density lipoprotein cholesterol, and insulin. Results: Times (mean [SD] min/d) accumulated by children in MVPA and being sedentary were 30 (21) and 354 (96), respectively. Time in MVPA was significantly associated with all cardiometabolic outcomes independent of sex, age, monitor wear time, time spent sedentary, and waist circumference (when not the outcome). Sedentary time was not associated with any outcome independent of time in MVPA. In the combined analyses, higher levels of MVPA were associated with better cardiometabolic risk factors across tertiles of sedentary time. The differences in outcomes between higher and lower MVPA were greater with lower sedentary time. Mean differences in waist circumference between the bottom and top tertiles of MVPA were 5.6 cm (95% CI, 4.8-6.4 cm) for high sedentary time and 3.6 cm (95% CI, 2.8-4.3 cm) for low sedentary time. Mean differences in systolic blood pressure for high and low sedentary time were 0.7 mm Hg (95% CI, −0.07 to 1.6) and 2.5 mm Hg (95% CI, 1.7-3.3), and for high-density lipoprotein cholesterol, differences were −2.6 mg/dL (95% CI, −1.4 to −3.9) and −4.5 mg/dL (95% CI, −3.3 to −5.6), respectively. Geometric mean differences for insulin and triglycerides showed similar variation. Those in the top tertile of MVPA accumulated more than 35 minutes per day in this intensity level compared with fewer than 18 minutes per day for those in the bottom tertile. In prospective analyses (N = 6413 at 2.1 years’ follow-up), MVPA and sedentary time were not associated with waist circumference at follow-up, but a higher waist circumference at baseline was associated with higher amounts of sedentary time at follow-up. Conclusion: Higher MVPA time by children and adolescents was associated with better cardiometabolic risk factors regardless of the amount of sedentary time.

• Ridgway, Charlotte L.; Brage, Søren Karl; Anderssen, Sigmund Alfred; Sardinha, Luis B.; Andersen, Lars Bo & Ekelund, Ulf (2011). Do Physical Activity and Aerobic Fitness Moderate the Association Between Birth Weight and Metabolic Risk in Youth? The European Youth Heart Study. Diabetes Care. ISSN 0149-5992. 34(1), p. 187–192. doi: 10.2337/dc10-1178. Full text in Research Archive Show summary

  OBJECTIVE: Lower birth weight has been associated with a greater risk of metabolic diseases. The aim of this study was examine whether physical activity and aerobic fitness may modify associations between birth weigh and metabolic risk. RESEARCH DESIGN AND METHODS: The European Youth Heart Study is a population-based study of 9 and 15 year olds (n = 1,254). Birth weight was maternally reported. Skin fold measures were used to calculate body fat and fat mass index (FMI = fat mass [kilograms]/height2). Insulin was measured using fasting blood samples. Physical activity was measured using a hip-worn accelerometer (MTI Actigraph) for >600 min/day for ≥3 days and is expressed as “average activity” (counts per minute) and time spent in above moderate intensity activity (>2000 cpm). Aerobic fitness was assessed using a maximal cycle ergometry test (watts per kilogram fat-free mass). RESULTS: Higher birth weight was associated with higher FMI (β = 0.49 [95% CI 0.21–0.80]; P = 0.001) and greater waist circumference (0.90 [0.32–1.47]; P < 0.001), adjusted for sex, age-group, sexual maturity, height, and socioeconomic status. Lower birth weight was associated with higher fasting insulin only after further adjustment for adolescent waist circumference and height (−0.059 [−0.107 to −0.011]; P = 0.016). There was no evidence for any modification of the associations after adjustment for physical activity or aerobic fitness. CONCLUSIONS: The present study did not find any evidence that physical activity or aerobic fitness can moderate the associations among higher birth weight and increased fat mass and greater waist circumference or between lower birth weight and insulin resistance in healthy children and adolescents.

• Ridgway, Charlotte L.; Brage, Søren Karl; Sharp, Stephen J.; Corder, Kirsten; Westgate, Kate L. & Sluijs, Esther van [Show all 12 contributors for this article] (2011). Does Birth Weight Influence Physical Activity in Youth? A Combined Analysis of Four Studies Using Objectively Measured Physical Activity. PLOS ONE. 6(1). doi: 10.1371/journal.pone.0016125. Full text in Research Archive
• Mountjoy, Margo; Andersen, Lars Bo; Armstrong, Neil; Biddle, Stuart; Boreham, Colin A.G. & Bedenbeck, Hans-Peter Brandl [Show all 24 contributors for this article] (2011). International Olympic Committee consensus statement on the health and fitness of young people through physical activity and sport. British Journal of Sports Medicine. ISSN 0306-3674. 45(11), p. 839–848. doi: 10.1136/bjsports-2011-090228. Full text in Research Archive
• Ridgway, C.L.; Brage, Søren; Anderssen, Sigmund Alfred; Sardinha, Luis B.; Andersen, Lars Bo & Ekelund, Ulf (2011). Fat-free mass mediates the association between birth weight and aerobic fitness in youth. International Journal of Pediatric Obesity. ISSN 1747-7166. 6(2-2), p. E590–E596. doi: 10.3109/17477166.2010.526225. Full text in Research Archive Show summary

  Objective. To investigate whether birth weight acts as a biological determinant of later aerobic fitness, and whether fat-free mass may mediate this association. Methods. The European Youth Heart Study (EYHS) is a population-based cohort of two age groups (9 and 15 years) from Denmark, Portugal, Estonia and Norway. Children with parentally reported birth weight >1.5 kg were included (n = 2 749). Data were collected on weight, height, and skinfold measures to estimate fat mass and fat-free mass. Aerobic fitness (peak power, watts) was assessed using a maximal, progressive cycle ergometer test. Physical activity was collected in a subset (n = 1 505) using a hip-worn accelerometer and defined as total activity counts/wear time, all children with >600 minutes/day for ≥3 days of wear were included. Results. Lower birth weight was associated with lower aerobic fitness, after adjusting for sex, age group, country, sexual maturity and socio-economic status (ß = 5.4; 95% CI: 3.5, 7.3 W per 1 kg increase in birth weight, p < 0.001). When fat-free mass was introduced as a covariate in the model, the association between birth weight and aerobic fitness was almost completely attenuated (p = 0.7). Birth weight was also significantly associated with fat-free mass (ß = 1.4; 95% CI: 1.1, 1.8, p < 0.001) and fat-free mass was significantly associated with aerobic fitness (ß = 3.6; 95% CI: 3.4, 3.7, p < 0.001). Further adjustment for physical activity did not alter the findings. Conclusion. Birth weight may have long-term influences on fat-free mass and differences in fat-free mass mediate the observed association between birth weight and aerobic fitness.

• Ekelund, Ulf; Besson, Herve; Luan, Jian'an; May, Anne M.; Sharp, Stephen J. & Brage, Søren Karl [Show all 47 contributors for this article] (2011). Physical activity and gain in abdominal adiposity and body weight: prospective cohort study in 288,498 men and women. American Journal of Clinical Nutrition. ISSN 0002-9165. 93(4), p. 826–835. doi: 10.3945/ajcn.110.006593. Full text in Research Archive
• Nilsson, A.; Anderssen, Sigmund A.; Andersen, Lars Bo; Froberg, Karsten; Riddoch, Chris J. & Sardinha, Luis B. [Show all 7 contributors for this article] (2009). Between- and within-day variability in physical activity and inactivity in 9-and 15-year-old European children. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 19(1), p. 10–18. doi: 10.1111/j.1600-0838.2007.00762.x. Full text in Research Archive Show summary

  To examine differences in levels of physical activity (PA), time spent at moderate-to-vigorous intensity PA (MVPA) and time spent sedentary between and within days in children from four European countries, 1954 9 - and 15-year-olds were included. PA was measured during 2 weekdays and 2 weekend days using the manufacturing technology-incorporated (MTI) accelerometer. Average count per minute, time spent sedentary, time spent at MVPA and the proportion of children accumulating >= 60 min of MVPA were calculated. Data were compared between weekdays and weekend days and between school time and leisure-time. Although not entirely consistent across countries, overall PA, time spent sedentary and the proportion of children accumulating >= 60 min of MVPA were higher during weekdays compared with weekend days. Differences in overall PA between school time and leisure-time were highly inconsistent between countries. Few children (4-31%) accumulated >= 60 min of MVPA either during school time or during leisure-time. Differences in activity patterns between weekdays and weekend days are explained by less accumulated time in MVPA during weekend days. Weekend days and leisure-time during weekdays seem appropriate targets when promoting PA in order to increase the proportion of children achieving current recommendations on health-enhancing PA.

• Ekelund, Ulf; Anderssen, Sigmund A.; Andersen, Lars Bo; Riddoch, Chris J.; Sardinha, Luis B. & Luan, Jian'an [Show all 8 contributors for this article] (2009). Prevalence and correlates of the metabolic syndrome in a population-based sample of European youth. American Journal of Clinical Nutrition. ISSN 0002-9165. 89(1), p. 90–96. doi: 10.3945/ajcn.2008.26649. Full text in Research Archive Show summary

  Conclusions: High maternal BMI and low levels of cardiorespiratory fitness and physical activity independently contribute to the MetS and may be targets for future interventions. Relatively small increases in physical activity may significantly reduce the risk of MetS in healthy children. Am J Clin Nutr 2009; 89: 90-6.

• Nilsson, A.; Andersen, Lars Bo; Ommundsen, Yngvar; Froberg, Karsten; Sardinha, Luis B. & Piehl-Aulin, Karin [Show all 7 contributors for this article] (2009). Correlates of objectively assessed physical activity and sedentary time in children: a cross-sectional study (The European Youth Heart Study). BMC Public Health. 9. doi: 10.1186/1471-2458-9-322. Full text in Research Archive Show summary

  Conclusion: Frequency of outdoor play after school is a significant correlate for daily time in MVPA in 9-year-olds, while this correlate is attenuated in favour of participation in sport and exercise in clubs in 15-year-olds. Targeting walking to school or reduced TV viewing time in order to increase time in daily MVPA in children is unlikely to be sufficient. Correlates related to time spent sedentary need further examination.

• Sardinha, Luis B.; Andersen, Lars Bo; Anderssen, Sigmund A.; Quitéro, Ana L.; Ornelas, Rui & Froberg, Karsten [Show all 8 contributors for this article] (2008). Objectively measured time spent sedentary is associated with insulin resistance independent of overall and central body fat in 9-to 10-year-old Portuguese children. Diabetes Care. ISSN 0149-5992. 31(3), p. 569–575. doi: 10.2337/dc07-1286. Full text in Research Archive Show summary

  CONCLUSIONS - Physical activity is associated with insulin resistance independent of total and central fat mass in children. Our results emphasize the importance of decreasing sedentary behavior and increasing time spent in moderate- and vigorous-intensity activity in children, which may have beneficial effects on metabolic risk factors regardless of the degree of adiposity.

• Nilsson, A.; Brage, Søren; Riddoch, Chris J.; Anderssen, Sigmund A.; Sardinha, Luis B. & Wedderkopp, Niels [Show all 8 contributors for this article] (2008). Comparison of equations for predicting energy expenditure from accelerometer counts in children. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 18(5), p. 643–650. doi: 10.1111/j.1600-0838.2007.00694.x. Full text in Research Archive Show summary

  Several prediction equations developed to convert body movement measured by accelerometry into energy expenditure have been published. The aim of this study was to examine the degree of agreement between three different prediction equations, when applied to data on physical activity in a large sample of children. We examined 1321 children (663 boys, 658 girls; mean age 9.6 +/- 0.4 years) from four different countries. Physical activity was measured by the MTI accelerometer. One equation, derived from doubly labeled water (DLW) measurements, was compared with one treadmill-based (TM) and one room calorimeter-based (CAL) equation (mixture of activities). Predicted physical activity energy expenditure (PAEE) was the main outcome variable. In comparison with DLW-predicted PAEE, both laboratory-derived equations significantly (P < 0.001) overestimated PAEE by 17% and 83%, respectively, when based on a 24-h prediction, while the TM equation significantly (P < 0.001) underestimated PAEE by 46%, when based on awake time only. In contrast, the CAL equation agreed better with the DLW equation under the awake time assumption. Predicted PAEE differ substantially between equations, depending on time-frame assumptions, and interpretations of average levels of PAEE in children from available equations should be made with caution. Further development of equations applicable to free-living scenarios is needed.

• Ekelund, Ulf; Anderssen, Sigmund A.; Froberg, Karsten; Sardinha, Luis B.; Andersen, Lars Bo & Brage, Søren (2007). Independent associations of physical activity and cardiorespiratory fitness with metabolic risk factors in children: the European youth heart study. Diabetologia. ISSN 0012-186X. 50(9), p. 1832–1840. Full text in Research Archive Show summary

  Conclusions/interpretation PA and CRF are separately and independently associated with individual and clustered metabolic risk factors in children. The association between CRF and clustered risk is partly mediated or confounded by adiposity, whereas the association between activity and clustered risk is independent of adiposity. Our results suggest that fitness and activity affect metabolic risk through different pathways.

• Andersen, Lars Bo; Harro, Maarike; Sardinha, Luis B.; Froberg, Karsten; Ekelund, Ulf & Brage, Søren [Show all 7 contributors for this article] (2006). Physical activity and clustered cardiovascular risk in children: a cross-sectional study (The European Youth Heart Study). The Lancet. ISSN 0140-6736. 368(9532), p. 299–304. Full text in Research Archive Show summary

  Interpretation Physical activity levels should be higher than the current international guidelines of at least 1 h per day of physical activity of at least moderate intensity to prevent clustering of cardiovascular disease risk factors.

• Andersen, Lars Bo; Anderssen, Sigmund A.; Brage, Søren; Ekelund, Ulf & Froberg, Karsten (2006). Fysisk aktivitet og ophobning af cardiovaskulære risikofaktorer : [en sekundær publikation fra the European Youth Heart Study]. Ugeskrift for Læger. ISSN 0041-5782. 168(47), p. 4101–4103. Full text in Research Archive
• Ekelund, Ulf; Brage, Søren; Froberg, Karsten; Harro, Maarike; Anderssen, Sigmund A. & Sardinha, Luis B. [Show all 8 contributors for this article] (2006). TV viewing and physical activity are independently associated with metabolic risk in children : the European Youth Heart Study. PLoS Medicine. ISSN 1549-1277. 3(12), p. 488–488. Full text in Research Archive
• Riddoch, Chris J.; Edwards, Dawn; Page, Angie S.; Froberg, Karsten; Anderssen, Sigmund A. & Wedderkopp, Niels [Show all 15 contributors for this article] (2005). The European Youth Heart Study : cardiovascular disease risk factors in children : rationale, aims, study design and validation of methods. ?. 2(1), p. 115–129. Full text in Research Archive
• Ekelund, Ulf; Sardinha, Luis B.; Anderssen, Sigmund A.; Harro, Maarike; Francks, Paul W. & Brage, Søren [Show all 10 contributors for this article] (2005). Level of Physical Activity in Children: Relevance of sedentary behaviors. American Journal of Clinical Nutrition. ISSN 0002-9165. 81(6), p. 1449–1449. Full text in Research Archive
• Brage, Søren; Wedderkopp, Niels; Ekelund, Ulf; Francks, Paul W.; Wareham, Nick & Andersen, Lars Bo [Show all 7 contributors for this article] (2004). Features of the metabolic syndrome are associated with objectively measured physical activity and fitness in Danish children : the European Youth Heart Study (EYHS). Diabetes Care. ISSN 0149-5992. 27(9), p. 2141–2148. Full text in Research Archive
• Riddoch, Chris J.; Wedderkopp, Niels; Harro, Maarike; Klasson-Heggebø, Lena; Sardinha, Luis B. & Cooper, Ashley R. [Show all 8 contributors for this article] (2004). Physical activity levels and patterns of 9 and 15 year old European children. ?. 36(1), p. 86–92. Full text in Research Archive
• Brage, Søren; Brage, Niels; Francks, Paul W.; Ekelund, Ulf; Wong, M.Y. & Froberg, Karsten [Show all 7 contributors for this article] (2004). Branched equation modelling of simultaneous accelerometryand heart rate monitoring improves estimate of directly measured physical activity energy ex-penditure. European Journal of Applied Physiology. ISSN 1439-6319. 96, p. 343–351. Full text in Research Archive
• Brage, Søren; Wedderkopp, Niels; Ekelund, Ulf; Francks, Paul W.; Wareham, Nick & Andersen, Lars Bo [Show all 7 contributors for this article] (2004). Objectively measured physical activity correlates with indices of insulin resistance in Danish children : the EuropeanYouth Heart study (EYHS). International Journal of Obesity. ISSN 0307-0565. 28(11), p. 1503–1508. Full text in Research Archive
• Ekelund, Ulf; Sardinha, Luis B.; Anderssen, Sigmund A.; Harro, Maarike; Francks, Paul W. & Brage, Søren [Show all 9 contributors for this article] (2004). Associations between objectively assessed physical activity and indica. American Journal of Clinical Nutrition. ISSN 0002-9165. 80, p. 584–590. Full text in Research Archive
• Ekelund, Ulf; Yngve, Agneta & Sjöström, Michael (2004). Body movement and physical activity energy expenditure in children and adolescents: how to adjust for differences in body size and age. American Journal of Clinical Nutrition. ISSN 0002-9165. 79(5), p. 851–856. Full text in Research Archive
• Poortvliet, Eric; Yngve, Agneta; Ekelund, Ulf; Hurtig-Wennlöf, Anita; Nilsson, Andreas & Hagstromer, Maria [Show all 7 contributors for this article] (2003). The European Youth Heart Survey (EYHS) An international study that addresses the multi-dimensional issues of CVD risk factors. Forum of nutrition. ISSN 1660-0347. p. 254–255. Full text in Research Archive
• Sjöström, Michael; Yngve, Agneta; Poortvliet, Eric; Ekelund, Ulf; Hurtig-Wennlöf, Anita & Nilsson, Andreas [Show all 7 contributors for this article] (2003). Adolescents nutriiton - a multidimensional challenge. Forum of nutrition. ISSN 1660-0347. p. 253–254. Full text in Research Archive
• Craig, Cora L.; Marshall, Allison; Sjöström, Michael; Baumann, Adrian; Booth, Michael L. & Ainsworth, Barbara E. [Show all 11 contributors for this article] (2003). The IPAQ consensus group and the IPAQ Reliability and Validity Study Group, The International Physical activity questionnaire (IPAQ): a comprehensive reliability and validity study in twelve countries. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 35(8), p. 1381–1395. Full text in Research Archive
• Yngve, Agneta; Nilsson, Andreas; Sjöström, Michael & Ekelund, Ulf (2003). Effect of monitor placement and of activity setting on the MTI accelerometer output. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 35(2), p. 320–326. Full text in Research Archive
• Sjöström, Michael; Ekelund, Ulf; Yngve, Agneta; Nilsson, Andreas & Hurtig-Wennlöf, Anita (2002). European Youth Heart Study - Om barnens vardagliga aktivitet och gällande rekommendationer. Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning. ISSN 1103-4629. 11(3), p. 62–67. Full text in Research Archive
• Nilsson, Andreas; Ekelund, Ulf; Yngve, Agneta & Sjöström, Michael (2002). Assessing physical activity among children with activity monitors using different time sampling intervals and placements. Pediatric Exercise Science. ISSN 0899-8493. 14, p. 87–96. Full text in Research Archive
• Ekelund, Ulf; Åman, Jan; Yngve, Agneta; Renman, C; Westerterp, Klaas & Sjöström, Michael (2002). Physical activity but not energy expenditure is reduced in obese adolescents: a case control study. American Journal of Clinical Nutrition. ISSN 0002-9165. 76, p. 935–941. Full text in Research Archive
• Ekelund, Ulf; Yngve, Agneta; Westerterp, Klaas & Sjöström, Michael (2002). Energy expenditure assessed by heart rate and doubly labelled water in young athletes. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 34(8), p. 1360–1366. Full text in Research Archive
• Ekelund, Ulf; Yngve, Agneta & Poortvliet, Eric (2001). Energiförbrukning och fysisk aktivitet bland unga elitidrottare - en tillämpning av kontinuerlig hjärtfrekvensregistrering. Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning. ISSN 1103-4629. 10(2), p. 29–33. Full text in Research Archive
• Sjöström, Michael; Yngve, Agneta & Ekelund, Ulf (2001). Physical activity in the North; similar problems but different approaches. TemaNord. ISSN 0908-6692. p. 55–60. Full text in Research Archive
• Sjöström, Michael; Yngve, Agneta & Ekelund, Ulf (2001). Environmental planning and public health nutrition. TemaNord. ISSN 0908-6692. p. 117–124. Full text in Research Archive
• Yngve, Agneta; Ekelund, Ulf & Sjöström, Michael (2001). Social Marketing in Public Health Nutrition: Also for the Nordic Countries? TemaNord. ISSN 0908-6692. p. 79–87. Full text in Research Archive
• Ekelund, Ulf; Poortvliet, Eric; Yngve, Agneta; Hurtig-Wennlöf, Anita; Nilsson, Andreas & Sjöström, Michael (2001). Heart rate as an indicator of physical activity in adolescents. European Journal of Applied Physiology. ISSN 1439-6319. 85, p. 244–249. Full text in Research Archive
• Ekelund, Ulf; Poortvliet, Eric; Yngve, Agneta; Nilsson, Andreas; Holmberg, Anders & Sjöström, Michael (2001). Physical activity in relation to aerobic fitness and body fat in 14-to 15-year old boys and girls. European Journal of Applied Physiology. ISSN 1439-6319. 85, p. 195–201. Full text in Research Archive
• Sjöström, Michael; Yngve, Agneta; Ekelund, Ulf & Hagstromer, Maria (2001). IPAQ - en rörelse i tiden; Svenskt initiativ snart global standard? Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning. ISSN 1103-4629. 10(2), p. 13–17. Full text in Research Archive
• Ekelund, Ulf; Sjöström, Michael; Yngve, Agneta; Poortvliet, Eric; Nilsson, Andreas & Froberg, Karsten [Show all 8 contributors for this article] (2001). Physical activity assessed by activity monitor and doubly labelled water in children. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 33, p. 275–281. Full text in Research Archive
• Sjöström, Michael; Yngve, Agneta; Warm, Daniel; Ekelund, Ulf; Isaksson, Per & Poortvliet, Eric (2000). European Master's in public health nutrition. Socialmedicinsk Tidskrift (SMT). ISSN 0037-833X. p. 170–178. Full text in Research Archive
• Ekelund, Ulf; Poortvliet, Eric; Yngve, Agneta; Westerterp, Klaas; Froberg, Karsten & Wedderkopp, Niels [Show all 8 contributors for this article] (2000). Total Energy Expenditure as a function of activity countsd, anthropometric variables and sex in 9-year old children. Measurement in Physical Education and Exercise Science. ISSN 1091-367X. 4(4), p. 251–273. Full text in Research Archive
• Sjöström, Michael; Ekelund, Ulf & Yngve, Agneta (2000). How active are our children? Hur aktiva är våra barn och ungdomar? Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning. ISSN 1103-4629. p. 14–18. Full text in Research Archive
• Ekelund, Ulf; Yngve, Agneta; Sjöström, Michael & Westerterp, Klaas (2000). Field evaluation of the Computer Science and Application's Inc Activity Monitor during running and skating training in adolescent athletes. International Journal of Sports Medicine (IJSM). ISSN 0172-4622. 21, p. 1–7. Full text in Research Archive
• Ekelund, Ulf; Sjöström, Michael; Yngve, Agneta & Nilsson, Andreas (2000). Total daily energy expenditure and pattern of physical activity measured by minute-by-minute heart rate monitoring in 14-15 year old Swedish adolescents. European Journal of Clinical Nutrition. ISSN 0954-3007. 54, p. 195–202. Full text in Research Archive
• Sjöström, Michael; Yngve, Agneta; Poortvliet, Eric; Warm, Daniel & Ekelund, Ulf (1999). Diet, physical activity - interactions for health; public health nutition in the European perspective. Public Health Nutrition (PHN). ISSN 1368-9800. p. 453–459. Full text in Research Archive
• Ekelund, Ulf; Yngve, Agneta & Sjöström, Michael (1999). Total daily energy expenditure and patterns of physical activity in adolescents assessed by two different methods. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 9, p. 257–264. Full text in Research Archive

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• Jakobsen, Siw Ellen; Ekelund, Ulf & Aukan, Marthe Isaksen (2025). Fedme handler lite om stillesitting, mener forskere. [Internet]. Forskning.no. Full text in Research Archive Show summary

  Nesten alt handler om hva vi putter i munnen, fastslår en ny studie.

• Cillekens, Bart; Coenen, Pieter; Huysmans, Maaike A.; Holtermann, Andreas; Troiano, Richard P. & Mork, Paul Jarle [Show all 43 contributors for this article] (2025). Corrigendum to “Should workers be physically active after work? Associations of leisure-time physical activity with cardiovascular and all-cause mortality across occupational physical activity levels—An individual participant data meta-analysis” (J Sport Health Sci 14 [2025] 100987) (Journal of Sport and Health Science (2025) 14, (S2095254624001431), (10.1016/j.jshs.2024.100987)). Journal of Sport and Health Science. ISSN 2095-2546. 14. doi: 10.1016/j.jshs.2025.101037. Full text in Research Archive
• Bajunaid, Rania; Niu, Chaoqun; Hambly, Catherine; Liu, Zongfang; Yamada, Yosuke & Aleman-Mateo, Heliodoro [Show all 98 contributors for this article] (2025). Correction to: Predictive equation derived from 6,497 doubly labelled water measurements enables the detection of erroneous self-reported energy intake (Nature Food, (2025), 6, 1, (58-71), 10.1038/s43016-024-01089-5). Nature Food. doi: 10.1038/s43016-025-01175-2. Full text in Research Archive
• Bratland-Sanda, Solfrid & Ekelund, Ulf (2025). Kan du bli i form av å gå på mølle på kontoret? [Internet]. Forskning.no. Full text in Research Archive
• Dalene, Knut Eirik; Lergenmuller, Simon; Hjellvik, Vidar; Stigum, Hein; Meyer, Haakon Eduard & Nystad, Wenche [Show all 13 contributors for this article] (2024). Noncommunicable disease risk factor groups, socioeconomic position and longevity in Norway: a prospective cohort study of 576 299 men and women – the NCDNOR project. Full text in Research Archive
• Dalene, Knut Eirik; Lergenmuller, Simon; Sund, Erik Reidar; Krokstad, Steinar; Hopstock, Laila Arnesdatter & Nystad, Wenche [Show all 13 contributors for this article] (2024). Latent risk factor profiles in the Norwegian adult population over time and their association with premature NCD mortality – the NCDNOR project. Full text in Research Archive
• Gill, Jason M.R.; Chico, Timothy J.; Doherty, Aiden; Dunn, Jessilyn; Ekelund, Ulf & Katzmarzyk, Peter T. [Show all 9 contributors for this article] (2023). Potential impact of wearables on physical activity guidelines and interventions: Opportunities and challenges. British Journal of Sports Medicine. ISSN 0306-3674. doi: 10.1136/bjsports-2023-106822. Full text in Research Archive
• Wang, Eivind; Ekelund, Ulf & Solberg, Trine (2022). Treningsforsker lei trendene - dette er treningen som virkelig fungerer. [Journal]. Nidaros Pluss. Full text in Research Archive
• Jansson, Eva; Wennberg, Patrik; Anderssen, Sigmund Alfred; Ekelund, Ulf; Dohrn, Ing-Mari & Hagströmer, Maria (2022). Sitt mindre – all rörelse räknas. Läkartidningen. ISSN 0023-7205. 119. Full text in Research Archive
• Mañas, Asier; Cruz, Borja del Pozo; Ekelund, Ulf; Reyna, José Losa; Gómez, Irene Rodríguez & Carreño, José Antonio Carnicero [Show all 9 contributors for this article] (2022). Response to McAvoy and Tudor-Locke on their commentary on our manuscript: “Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults: A prospective cohort study”. Journal of Sport and Health Science. ISSN 2095-2546. 11(6), p. 639–640. doi: 10.1016/j.jshs.2022.09.001. Full text in Research Archive
• Wang, Eivind; Ekelund, Ulf & Solberg, Trine (2022). Treningsforsker lei trendene - dette er treningen som virkelig fungerer. [Journal]. Bygdeposten Pluss. Full text in Research Archive
• Wang, Eivind; Ekelund, Ulf & Solberg, Trine (2022). Treningsforsker lei trendene - dette er treningen som virkelig fungerer. [Journal]. Sandefjords Blad Pluss. Full text in Research Archive
• Wang, Eivind; Ekelund, Ulf & Solberg, Trine (2022). Treningsforsker lei trendene – dette er treningen som virkelig fungerer. [Internet]. ifinnmark.no. Full text in Research Archive
• Sagelv, Edvard Hamnvik; Hopstock, Laila Arnesdatter; Morseth, Bente; Hansen, Bjørge Hermann; Steene-Johannessen, Jostein & Anderssen, Sigmund Alfred [Show all 13 contributors for this article] (2022). Physical activity and mortality: Effect modification by sedentary time. An individual participant data analysis of four cohorts with accelerometry measured physical activity. Full text in Research Archive
• Dalene, Knut Eirik; Tarp, Jakob & Ekelund, Ulf (2021). The role of occupational physical activity on longevity – Authors' reply. The Lancet Public Health. ISSN 2468-2667. 6(8), p. E545–E545. doi: 10.1016/S2468-2667(21)00155-9. Full text in Research Archive
• Ding, Ding; Lee, I-Min; Bauman, Adrian; Ekelund, Ulf & Stamatakis, Emmanuel (2021). Dietary risk versus physical inactivity: a forced comparison with policy implications? The Lancet. ISSN 0140-6736. 397(10286), p. 1709–1710. doi: 10.1016/S0140-6736(21)00801-1. Full text in Research Archive
• Stamatakis, Emmanuel; Ding, Ding; Ekelund, Ulf & Bauman, Adrian (2021). Sliding down the risk factor rankings: Reasons for and consequences of the dramatic downgrading of physical activity in the Global Burden of Disease 2019. British Journal of Sports Medicine. ISSN 0306-3674. 55(21), p. 1222–1223. doi: 10.1136/bjsports-2021-104064. Full text in Research Archive
• Ekelund, Ulf (2020). Physical activity and mortality - new data and new paradoxes? Full text in Research Archive
• Ekelund, Ulf; Dalene, Knut Eirik; Tarp, Jakob & Lee, I-Min (2020). Physical activity and mortality: what is the dose response and how big is the effect? British Journal of Sports Medicine. ISSN 0306-3674. 54(19), p. 1125–1126. doi: 10.1136/bjsports-2019-101765. Full text in Research Archive
• DiPietro, Loretta; Al-Ansari, Salih S.; Biddle, Stuart JH; Borodulin, Katja; Bull, Fiona C. & Buman, Matthew P. [Show all 29 contributors for this article] (2020). Advancing the global physical activity agenda: recommendations for future research by the 2020 WHO physical activity and sedentary behavior guidelines development group. International Journal of Behavioral Nutrition and Physical Activity. 17. doi: 10.1186/s12966-020-01042-2. Full text in Research Archive Show summary

  Background: In July, 2019, the World Health Organization (WHO) commenced work to update the 2010 Global Recommendations on Physical Activity for Health and established a Guideline Development Group (GDG) comprising expert public health scientists and practitioners to inform the drafting of the 2020 Guidelines on Physical Activity and Sedentary Behavior. The overall task of the GDG was to review the scientific evidence and provide expert advice to the WHO on the amount of physical activity and sedentary behavior associated with optimal health in children and adolescents, adults, older adults (> 64 years), and also specifically in pregnant and postpartum women and people living with chronic conditions or disabilities. Methods: The GDG reviewed the available evidence specific to each sub-population using systematic protocols and in doing so, identified a number of gaps in the existing literature. These proposed research gaps were discussed and verified by expert consensus among the entire GDG. Results: Evidence gaps across population sub-groups included a lack of information on: 1) the precise shape of the dose-response curve between physical activity and/or sedentary behavior and several of the health outcomes studied; 2) the health benefits of light-intensity physical activity and of breaking up sedentary time with light-intensity activity; 3) differences in the health effects of different types and domains of physical activity (leisure-time; occupational; transportation; household; education) and of sedentary behavior (occupational; screen time; television viewing); and 4) the joint association between physical activity and sedentary time with health outcomes across the life course. In addition, we acknowledge the need to conduct more population-based studies in low- and middle-income countries and in people living with disabilities and/or chronic disease, and to identify how various sociodemographic factors (age, sex, race/ethnicity, socioeconomic status) modify the health effects of physical activity, in order to address global health disparities. Conclusions: Although the 2020 WHO Guidelines for Physical Activity and Sedentary Behavior were informed by the most up-to-date research on the health effects of physical activity and sedentary time, there is still substantial work to be done in advancing the global physical activity agenda.

• Tarp, Jakob; Dalene, Knut Eirik; Hansen, Bjørge Hermann; Steene-Johannessen, Jostein & Ekelund, Ulf (2020). Double counting individuals in meta‐analysis artificially inflates precision. Comment on “Device‐measured light‐intensity physical activity and mortality: A meta‐analysis”. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(6), p. 1083–1084. doi: 10.1111/sms.13693. Full text in Research Archive
• Sagelv, Edvard Hamnvik; Ekelund, Ulf & Bludd, Ellen Kathrine (2020). Er du en aktiv Tromsøværing? [Internet]. Uit.no. Full text in Research Archive
• Sagelv, Edvard Hamnvik; Ekelund, Ulf; Johansson, Jonas; Brage, Søren; Horsch, Alexander & Hopstock, Laila Arnesdatter [Show all 7 contributors for this article] (2019). Comparing a short physical activity questionnaire with accelerometer measures as criterion validity: The Tromsø Study. Full text in Research Archive
• Sagelv, Edvard Hamnvik; Ekelund, Ulf; Johansson, Jonas; Welde, Boye; Grimsgaard, Sameline & Emaus, Nina [Show all 11 contributors for this article] (2019). Measures of adiposity and its association to physical activity: The Tromsø Study. Full text in Research Archive
• Stamatakis, Emmanuel; Koster, Annemarie; Hamer, Mark; Rangul, Vegar; Lee, I-Min & Bauman, Adrian [Show all 25 contributors for this article] (2019). Emerging collaborative research platforms for the next generation of physical activity, sleep and exercise medicine guidelines: the Prospective Physical Activity, Sitting, and Sleep consortium (ProPASS). British Journal of Sports Medicine. ISSN 0306-3674. 54(8), p. 435–437. doi: 10.1136/bjsports-2019-100786. Full text in Research Archive
• Tarp, Jakob; Dalene, Knut Eirik; Steene-Johannessen, Jostein & Ekelund, Ulf (2019). Comment on: "Cardiorespiratory Fitness in Childhood and Adolescence Affects Future Cardiovascular Risk Factors: A Systematic Review of Longitudinal Studies". Sports Medicine. ISSN 0112-1642. 49(1), p. 159–161. doi: 10.1007/s40279-018-01035-z. Full text in Research Archive
• Tarp, Jakob; Child, Abbey; White, Tom; Westgate, Kate; Bugge, Anna & Grøntved, Anders [Show all 21 contributors for this article] (2019). Correction to: Physical activity intensity, bout-duration, and cardiometabolic risk markers in children and adolescents (International Journal of Obesity, (2018), 42, 9, (1639-1650), 10.1038/s41366-018-0152-8). International Journal of Obesity. ISSN 0307-0565. 43(11), p. 2346–2346. doi: 10.1038/s41366-019-0465-2. Full text in Research Archive
• Ekelund, Ulf & Lee, I-Min (2019). Authors' reply to Johnson. BMJ. British Medical Journal. ISSN 0959-8146. 366. doi: 10.1136/bmj.l5715. Full text in Research Archive
• Jones, Paul Remy; Kvalheim, Olav Martin; Resaland, Geir Kåre; Anderssen, Sigmund Alfred & Ekelund, Ulf (2018). Lipoprotein subclasses and their associations with physical activity and sedentary time in Norwegian schoolchildren: The Active Smarter Kids study. Journal of Physical Activity and Health. ISSN 1543-3080. 15(10), p. 109–110. Full text in Research Archive
• Sagelv, Edvard Hamnvik; Ekelund, Ulf; Pedersen, Sigurd; Brage, Søren; Grimsgaard, Sameline & Nordström, Anna [Show all 9 contributors for this article] (2018). Physical Activity levels in Women and Men Measured by Accelerometer. The Tromsø Study. Full text in Research Archive
• Renninger, Marius; Løchen, Maja-Lisa; Ekelund, Ulf; Hopstock, Laila Arnesdatter; Jørgensen, Lone & Mathiesen, Ellisiv B. [Show all 10 contributors for this article] (2018). The independent and joint associations of physical activity and body mass index with myocardial infarction: The Tromsø Study. Full text in Research Archive
• Ekelund, Ulf; Bauman, Adrian & Lee, I-Min (2017). Effects of early physical exercise on later health ? Authors' reply. The Lancet. ISSN 0140-6736. 389(10071), p. 801–801. doi: 10.1016/S0140-6736(17)30506-8. Full text in Research Archive
• Stavnsbo, Mette; Resaland, Geir Kåre; Anderssen, Sigmund Alfred; Domazet, SL; Skrede, Turid & Kriemler, S [Show all 10 contributors for this article] (2017). Referanse verdier for kardiometabolske risikovariabler for barn og ungdommer. Full text in Research Archive
• Brug, Johannes; Ploeg, Hidde P van der; Loyen, Anne; Ahrens, Wolfgang; Allais, Olivier & Andersen, Lene Frost [Show all 34 contributors for this article] (2017). Determinants of diet and physical activity (DEDIPAC): A summary of findings. International Journal of Behavioral Nutrition and Physical Activity. 14(1). doi: 10.1186/s12966-017-0609-5. Full text in Research Archive Show summary

  The establishment of the Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub, 2013–2016, was the first action taken by the ‘Healthy Diet for a Healthy Life’ European Joint Programming Initiative. DEDIPAC aimed to provide better insight into the determinants of diet, physical activity and sedentary behaviour across the life course, i.e. insight into the causes of the causes of important, non-communicable diseases across Europe and beyond. DEDIPAC was launched in late 2013, and delivered its final report in late 2016. In this paper we give an overview of what was achieved in terms of furthering measurement and monitoring, providing overviews of the state-of-the-art in the field, and building toolboxes for further research and practice. Additionally, we propose some of the next steps that are now required to move forward in this field, arguing in favour of 1) sustaining the Knowledge Hub and developing it into a European virtual research institute and knowledge centre for determinants of behavioural nutrition and physical activity with close links to other parts of the world; 2) establishing a cohort study of families across all regions of Europe focusing specifically on the individual and contextual determinants of major, non-communicable disease; and 3) furthering DEDIPAC’s work on nutrition, physical activity, and sedentary behaviour policy evaluation and benchmarking across Europe by aligning with other international initiatives and by supporting harmonisation of pan-European surveillance

• Ekelund, Ulf & Skrede, Turid (2017). Reply to A Lu and R Wang. American Journal of Clinical Nutrition. ISSN 0002-9165. 106(3), p. 948–949. doi: 10.3945/ajcn.117.160143. Full text in Research Archive
• Sagelv, Edvard Hamnvik; Ekelund, Ulf & Stensrud, Trine (2016). A comparison between two different conditions of breaking up sedentary behaviour on glucose metabolism. Full text in Research Archive Show summary

  Conclusion: There is no effect of either breaking up sedentary behaviour each hour or performing 30 minutes of vigorous physical activity in one bout compared with prolonged sitting for six hours on glucose metabolism.

• Hansen, Bjørge Hermann; Nilsen, Ada Kristine Ofrim; Dalene, Knut Eirik; Steene-Johannessen, Jostein; Kolle, Elin & Ekelund, Ulf [Show all 7 contributors for this article] (2016). Cross-sectional and Longitudinal Associations of Replacing Sedentary Time with Active Behaviors on the Body Mass Index. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 48, p. 232–232. doi: 10.1249/01.mss.0000485698.85376.e6. Full text in Research Archive
• Smith, Lee; Ekelund, Ulf & Hamer, Mark (2015). The Potential Yield of Non-Exercise Physical Activity Energy Expenditure in Public Health. Sports Medicine. ISSN 0112-1642. 45(4), p. 449–452. doi: 10.1007/s40279-015-0310-2. Full text in Research Archive
• Sardinha, Luís B.; Ekelund, Ulf; Santos, Leonardo dos; Cyrino, Edilson S.; Silva, Analiza M. & Santos, Diana A. (2015). Breaking-up sedentary time is associated with impairment in activities of daily living. Experimental Gerontology. ISSN 0531-5565. 72, p. 278–278. doi: 10.1016/j.exger.2015.10.010. Full text in Research Archive
• Borch, Kristin Benjaminsen; Lund, Eiliv; Ekelund, Ulf & Brage, Søren (2015). Physical activity assessment in the NOWAC study - Criterion validity of a 10-category scale for ranking physical activity in Norwegian women. Full text in Research Archive
• Hildebrand, Maria & Ekelund, Ulf (2015). Reply to R Wang and P Chen. American Journal of Clinical Nutrition. ISSN 0002-9165. 102(3), p. 713–714. doi: 10.3945/ajcn.115.117275. Full text in Research Archive
• Hallas, Peter; Ekelund, Ulf; Bjørnsen, Lars Petter & Brabrand, Mikkel (2013). Hoping for a domino effect: a new specialty in Sweden is a breath of fresh air for the development of Scandinavian emergency medicine. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 21:26. doi: 10.1186/1757-7241-21-26. Full text in Research Archive
• Ekelund, Ulf; Bjørnsen, Lars Petter; Brabrand, Mikkel & Hallas, Peter (2013). Hoping for a domino effect : a new specialty in Sweden is a breath of fresh air for the development of Scandinavian emergency medicine. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 21:26. doi: 10.1186/1757-7241-21-26. Full text in Research Archive
• Ekelund, Ulf (2012). Commentary: Too much sitting-a public health threat? International Journal of Epidemiology. ISSN 0300-5771. 41(5), p. 1353–1355. doi: 10.1093/ije/dys128. Full text in Research Archive
• Ekelund, Ulf (2012). Too much sitting still - a public health threat? International Journal of Epidemiology. ISSN 0300-5771. 41(5), p. 1353–1355. doi: 10.1093/ije/dys128. Full text in Research Archive
• Ekelund, Ulf; Anderssen, Sigmund A.; Andersen, Lars Bo; Froberg, Karsten; Sardinha, Luis B. & Brage, Søren (2007). Independent contributions of physical activity and cardiorespiratory fitness with individual and clustered metabolic riskfactors in children: the European Youth Heart Study. Medicine & Science in Sports & Exercise. ISSN 0195-9131. p. 44–45. Full text in Research Archive
• Ekelund, Ulf; Sardinha, Luis B.; Anderssen, Sigmund A.; Harro, Maarike; Franks, PW & Brage, Søren [Show all 10 contributors for this article] (2007). Reply to C Maffeis: "Level of physical activity and adiposity in children: relevance of sedentary.". American Journal of Clinical Nutrition. ISSN 0002-9165. p. 1449–54. Full text in Research Archive
• Ekelund, Ulf; Anderssen, Sigmund A.; Andersen, Lars Bo; Froberg, Karsten; Sardinha, Luis B. & Brage, Søren (2007). Independent contributions of physical activity and cardiorespiratory fitness with individual and clustered metabolic riskfactors in children. Full text in Research Archive
• Andersen, Lars Bo; Froberg, Karsten; Brage, Søren; Ekelund, Ulf & Anderssen, Sigmund A. (2006). Physical activity and cardiovascular risk in children. The Lancet. ISSN 0140-6736. p. 1326–1327. Full text in Research Archive
• Andersen, Lars Bo; Ekelund, Ulf; Brage, Søren; Froberg, Karsten & Anderssen, Sigmund A. (2006). Physical activity and cardiovascular risk in children. Authors reply to comment by M. Hamer and T. Koga. The Lancet. ISSN 0140-6736. p. 1326–1327. Full text in Research Archive
• Ekelund, Ulf; Sardhina, Luis B.; Anderssen, Sigmund A.; Harro, Maarike; Andersen, Lars Bo & Riddoch, Chris J. [Show all 7 contributors for this article] (2004). Associations between physical activity and body fatness in 9-to-10-year old children : the European youth heart study. Full text in Research Archive
• Steene-Johannessen, Jostein; Hansen, Bjørge Hermann; Teinung, Elisabeth; Kolle, Elin; Riiser, Amund & Mølmen, Knut Sindre [Show all 12 contributors for this article] (2024). Fysisk form blant voksne og eldre i Norge 2022-2023 (Kan3). Folkehelseinstituttet. Full text in Research Archive Show summary

  <b>Sammendrag av hovedfunn</b> - Kartleggingen av fysisk form blant voksne og eldre i Norge 2022-23 (Kan3 fase 2) er utført ved Norges idrettshøgskole i samarbeid med Folkehelseinstituttet. Kan3 fase 2 inngår som en del av det nasjonale kartleggingssystemet for fysisk aktivitet og fysisk form der formålet er å følge opp tidligere undersøkelser av voksne og eldre for å øke kunnskapen om status, trender og utviklingen av fysisk form i den norske befolkingen. Datainnsamlingen i Kan3 fase 2 er gjennomført i samarbeid med Universitetet i Stavanger, Universitetet i Agder, UiT Norges arktiske universitet, Høgskulen på Vestlandet og Høgskolen i Innlandet i perioden august 2022 til april 2023.<p> <p>Et tilfeldig utvalg av deltakere som deltok i Kan3 fase 1 (hovedutvalg) ble invitert til fysisk oppmøte for gjennomføring av tester for å måle fysisk form i Kan3 fase 2. Som beskrevet i Kan 3 fase 1 rapport ble det også rekruttert deltakere som var 67+ år gjennom egne rekrutteringsstrategier mot seniorsenter i de store byene. Disse deltakerne gjennomførte tester av gripestyrke, balanse og bevegelighet, men de gjennomførte ikke test av maksimalt oksygenopptak.<p> <p>Av totalt 2001 personer som ble invitert, samtykket 1503 personer til deltakelse i Kan3 fase 2. Som vist i Kan 3 fase 1 er utvalget noe selektert da det er forholdsvis flere med høy sosioøkonomisk status i utvalget sammenlignet med den øvrige befolkningen. Den samme selekteringen er følgelig med videre inn i fase 2, og det betyr at beregninger for fysisk form trolig vil være noe overestimert.<p> <p><b>Maksimalt oksygenopptak (VO2max)</b> - Menn hadde høyere maksimalt oksygenopptak enn kvinner i alle aldergrupper. Oksygenopptaket falt med henholdsvis 2.8 ml∙kg-1∙min-1 og 3.9 ml∙kg-1∙min-1 blant kvinner og menn per 10 års økning i alder. Blant både menn og kvinner, hadde den femtedelen av deltakerne med høyest oksygenopptak et oksygenopptak som var omtrent dobbelt så høyt som den femtedelen av deltakerne med lavest oksygenopptak. Deltakere som tilfredsstilte Helsedirektoratets anbefaling for fysisk aktivitet, hadde høyere oksygenopptak sammenlignet med de som ikke tilfredsstilte anbefalingen. Oksygenopptaket økte med høyere utdanningsnivå blant menn, men ikke blant kvinner.<p> <p><b>Gripestyrke, balanse og bevegelighet</b> - Yngre hadde høyere gripestyrke enn eldre, og menn hadde høyere gripestyrke enn kvinner. Balansen reduseres med økende alder og en stor reduksjon sees etter fylte 60 år. Generelt var bevegeligheten i hofte og skulderledd bedre blant kvinner enn menn. For begge kjønn reduseres bevegeligheten med økende alder. Det var ingen sammenheng mellom gripestyrke, balanse og utdanning, men bevegelighet i hofteledd økte med høyere utdanning blant kvinner.<p> <p><b>Trender</b> - Både menn og kvinner i Kan3 fase 2 hadde et høyere maksimalt oksygenopptak enn menn og kvinner som deltok i Kan1 fase 2 i 2008-09. Menn hadde et oksygenopptak som var 2.3 ml∙kg-1∙min-1 (95% KI: 1.1 – 3.4) høyere i Kan3 sammenliknet med i Kan1, og tilsvarende forskjell for kvinner var 2.6 ml∙kg-1∙min-1 (95% KI: 1.6 – 3.5). Dette tilsvarer en prosentuell forskjell mellom Kan1 og Kan3 på 6-7%. Data må dog tolkes med forsiktighet fordi utvalget i Kan 1 er noe ulikt utvalget i Kan 3. Det var ingen forskjeller i gripestyrke når vi sammenlignet deltakere i Kan3 med deltakere i Kan1.<p> <p><b>Praktiske implikasjoner</b> - I gjennomsnitt har deltakere i Kan3 et oksygenopptak som er godt over eller på nivå med foreslåtte internasjonale og nasjonale grenseverdier for anbefalt VO2max. Spredningen i materialet er imidlertid betydelig og for den femtedelen av deltakerne med lavest oksygenopptak ligger verdiene betydelig lavere enn anbefalte verdier, noe som kan gi økt risiko for sykdom og tidlig død. I denne gruppen vil selv dagligdagse aktiviteter, som det å gå i trapper eller å sykle kreve en så stor andel av det maksimale oksygenopptaket at det vil være vanskelig å delta i slike aktiviteter i mer enn noen få minutter. Oksygenopptaket er imidlertid trenbart uansett alder og utgangspunkt. En økning i det maksimale oksygenopptaket hos denne gruppen vil kunne ha stor betydning for å sikre en god fysisk funksjon, det vil si gi økt mestring av dagliglivets aktiviteter.<p> <p>Lav gripestyrke er også assosiert med økt risiko for sykelighet og tidlig død. Selv om muskelmassen og maksimal styrke faller naturlig med økende alder, vil regelmessig styrketrening kunne forebygge mye av dette fallet. Styrketrening er spesielt viktig fra 50–60-årsalderen, og selv personer over 70 år vil kunne øke både muskelmassen og styrken betraktelig ved å starte med regelmessig styrketrening.

• Hansen, Bjørge Hermann; Steene-Johannessen, Jostein; Kolle, Elin; Udahl, Karine; Kaupang, Oda Bjørge & Andersen, Inge Dehli [Show all 10 contributors for this article] (2023). Kartlegging av fysisk aktivitet blant voksne og eldre 2020-22 (Kan3). Folkehelseinstituttet. Full text in Research Archive Show summary

  Kartlegging av fysisk aktivitet og stillesittende tid blant voksne og eldre (Kan3) er utført ved Norges idrettshøgskole i samarbeid med Folkehelseinstituttet. Formålet med Kan3 er å følge opp tidligere undersøkelser av voksne og eldre for å øke kunnskapen om status, trender og utviklingen av fysisk aktivitet i den norske befolkingen. Kan3 inngår som en del av det nasjonale kartleggingssystemet av fysisk aktivitet og fysisk form. De norske ungKan- og Kan-undersøkelsene er unike ved at fysisk aktivitet er målt objektivt ved hjelp av akselerometre i populasjonsbaserte utvalg ved flere tidspunkt. Dette gir mer nøyaktige estimater av befolkingens fysiske aktivitetsnivå enn ved spørreskjemabaserte undersøkelser. Slik kunnskap er nødvendig for å kunne iverksette tiltak for å redusere stillesitting og øke det fysiske aktivitetsnivået.

• Kolle, Elin; Steene-Johannessen, Jostein; Säfvenbom, Reidar; Anderssen, Sigmund Alfred; Grydeland, May & Ekelund, Ulf [Show all 17 contributors for this article] (2019). Hovedrapport: School in motion. Utdanningsdirektoratet. Full text in Research Archive
• Klepp, Knut Inge; Lund-Blix, Nicolai Andre; Nystad, Wenche; Ekelund, Ulf; Andersen, SA & Belander, O [Show all 7 contributors for this article] (2017). Nasjonale landsrepresentative kartlegginger av fysisk aktivitet, fysisk form og tid i ro. Rapport fra arbeidsgruppen mars 2017. Folkehelseinstituttet. ISSN 9788280828453. Full text in Research Archive

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