Linn Christin Risvang

• Risvang, Linn Christin; Dijk, Jan Willem van; Baumgart, Julia Kathrin; Rice, Hannah; Liljegren, Anja M.F. & Strøm, Vegard [Vis alle 8 forfattere av denne artikkelen] (2025). High prevalence of low bone mineral density in wheelchair users regardless of sports participation: a cross-sectional analysis of the bonewheel study. European Journal of Applied Physiology. ISSN 1439-6319. s. 1–14. doi: 10.1007/s00421-025-06109-1. Fulltekst i vitenarkiv Vis sammendrag

  Purpose Wheelchair users are at increased risk of low bone mineral density (BMD). While BMD varies by sport among Paralympic athletes, it remains unclear whether sports participation protects against low BMD in the impaired population. This study compared BMD at several skeletal sites between sports-active and non-sports-active wheelchair users. Methods This study presents cross-sectional analyses of adult (18–60 years) wheelchair users with non-progressive impairments recruited for a subsequent multi-site intervention study. BMD and body composition were measured with dual-energy X-ray absorptiometry. Low BMD was defined as Z-score <–1.0. Multiple linear regression models assessed differences between sports-active (≥ 1 year organised; ≥3 training hours per week) and non-sports-active participants, and associations with impairment and exercise characteristics, and body composition. Results Sixty-three wheelchair users (age 37 ± 11 years; 41% female; 48% sports-active; 49% with acquired impairments) were included. Low BMD was prevalent in 33%, 81% and 77% at the spine, hip and femoral neck, respectively. Low BMD at the hip was less prevalent in sports-active compared to non-sports-active (p = 0.013), without differences in any BMD Z-score models (all p > 0.05). Acquired impairments was positively associated with lumbar spine BMD (p = 0.034), while full-time wheelchair use was negatively associated with femoral neck BMD (p = 0.036). Impairments and SCIM scores were associated with hip BMD (both p < 0.05). Conclusion Notably high prevalences of low BMD was found in this study, particularly at the hip and regardless of sports participation. Impairments and ambulatory ability appear the most influential on BMD. Targeted exercise interventions for bone health are warranted in this population.

• Weijer, Vera C. R.; Jonvik, Kristin Lundanes; Dam, Lotte Van; Risvang, Linn; Plasqui, Guy & Sandbakk, Øyvind Bucher [Vis alle 9 forfattere av denne artikkelen] (2024). Energy Requirements of Paralympic Athletes: Insights from the Doubly Labeled Water Approach. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 56(5), s. 963–971. doi: 10.1249/MSS.0000000000003379. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: Advanced insight in energy requirements of Paralympic athletes is imperative for optimizing their nutritional counseling. Given the lack of accurate data on total daily energy expenditure (TDEE) of Paralympic athletes, this study aimed to assess energy expenditure and nutritional intake of a large cohort of Paralympic athletes, across different sports and disabilities. Methods: In this cross-sectional study, 48 Dutch and Norwegian Paralympic athletes (19 male/29 female) with various disabilities, competing in Para cycling, wheelchair tennis, wheelchair basketball, Para Nordic skiing, and alpine skiing participated. TDEE was assessed by the gold standard doubly labeled water method over a 14-d period, resting metabolic rate by ventilated hood indirect calorimetry, energy intake by three unannounced 24-h dietary recalls, body composition by dual-energy x-ray absorptiometry, and exercise training duration by a training log. Results: Mean TDEE was 2908 ± 797 kcal·d−1, ranging from 2322 ± 340 kcal·d−1 for wheelchair basketball players to 3607 ± 1001 kcal·d−1 for Para cyclists. Regression analysis identified fat-free mass, exercise duration, and the presence of a spinal cord disorder as the primary predictors of TDEE, explaining up to 73% of the variance in TDEE. Athletes’ energy intake (2363 ± 905 kcal·d−1) was below their TDEE, whereas their body mass remained constant, indicating underreporting. Carbohydrate intake (4.1 ± 1.9 g·kg−1 body mass) was low, even when considering underreporting, whereas protein intake (1.8 ± 0.6 g·kg−1 body mass) was relatively high. Conclusions: Paralympic athletes display moderate- to high-energy expenditure, varying across sports and individuals. Much of the variation in TDEE can be attributed to individual differences in fat-free mass and exercise duration. This study establishes the benchmarks for energy requirements of Paralympic athletes, serving as the foundation for future dietary guidelines within this population.

• Weijer, Vera C.R.; Dijk, Jan-Willem van; Dam, Lotte van; Risvang, Linn; Bons, Judith & Raastad, Truls [Vis alle 8 forfattere av denne artikkelen] (2024). Do Paralympic athletes suffer from brittle bones? Prevalence and risk factors of low bone mineral density in Paralympic athletes. Bone Reports. 21. doi: 10.1016/j.bonr.2024.101767. Fulltekst i vitenarkiv Vis sammendrag

  Background: Bone health may be a concern in Paralympic athletes, given the presence of multiple risk factors predisposing these athletes to low bone mineral density (BMD). Objective: We aimed to assess the prevalence of low BMD among Paralympic athletes participating in various sport disciplines, and to identify potential risk factors for low BMD. Conclusions: In this cohort of Paralympic athletes, low BMD is mainly present at the hip, and to a lesser extent at the whole-body and lumbar spine. The most prominent risk factors for low BMD in Paralympic athletes are related to mechanical loading patterns, including wheelchair use, the type of sport, and body mass.

• Weijer, Vera C.R.; Jonvik, Kristin Lundanes; Dam, Lotte van; Risvang, Linn; Raastad, Truls & Loon, Luc J.C. van [Vis alle 7 forfattere av denne artikkelen] (2024). Measured and Predicted Resting Metabolic Rate of Dutch and Norwegian Paralympic Athletes. Journal of the Academy of Nutrition and Dietetics. ISSN 2212-2672. 125(2), s. 217–227. doi: 10.1016/j.jand.2024.05.010. Fulltekst i vitenarkiv Vis sammendrag

  Background: Although resting metabolic rate (RMR) is crucial for understanding athletes’ energy requirements, limited information is available on the RMR of Paralympic athletes. Objective: The aim of this study was to determine RMR and its predictors in a diverse cohort of Paralympic athletes and evaluate the agreement between measured and predicted RMR from both newly developed and pre-existing equations. Design: This cross-sectional study, conducted between September 2020 and September 2022 in the Netherlands and Norway, assessed RMR in Paralympic athletes by means of ventilated hood indirect calorimetry and body composition by means of dual-energy x-ray absorptiometry. Participants: Sixty-seven Paralympic athletes (male: n = 37; female: n = 30) competing in various sports, with a spinal cord disorder (n = 22), neurologic condition (n = 8), limb deficiency (n = 18), visual or hearing impairment (n = 7), or other disability (n = 12) participated. Main outcome measures: RMR, fat-free mass (FFM), body mass, and triiodothyronine (T3) concentrations were assessed. Statistical analyses: Multiple regression analyses were conducted with height, FFM, body mass, sex, T3 concentration, and disabilities as potential predictors of RMR. Differences between measured and predicted RMRs were analyzed for individual accuracy, root mean square error, and intraclass correlation. Results: Mean ± SD RMR was 1386 ± 258 kcal/d for females and 1686 ± 302 kcal/d for males. Regression analysis identified FFM, T3 concentrations, and the presence of a spinal cord disorder, as the main predictors of RMR (adjusted R2 = 0.71; F = 50.3; P ＜ .001). The novel prediction equations based on these data, as well as pre-existing equations of Chun and colleagues and Nightingale and Gorgey performed well on accuracy (＞60% of participants within 10% of measured RMR), had good reliability (intraclass correlation ＞0.78), and low root mean square error (≤141 kcal). Conclusions: FFM, total T3 concentrations, and presence of spinal cord disorder are the main predictors of RMR in Paralympic athletes. Both the current study’s prediction equations and those from Chun and colleagues and Nightingale and Gorgey align well with measured RMR, offering accurate prediction equations for the RMR of Paralympic athletes.

• Norum, Martin; Risvang, Linn; Bjørnsen, Thomas; Dimitriou, Lygeri; Rønning, Per Ola & Bjørgen, Morten [Vis alle 7 forfattere av denne artikkelen] (2020). Caffeine Increases Strength and Power Performance in Resistance-trained Females During Early Follicular Phase. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 30(11), s. 2116–2129. doi: 10.1111/sms.13776. Fulltekst i vitenarkiv Vis sammendrag

  The effects of 4 mg·kg−1caffeine ingestion on strength and power were investigated for the first time, in resistance‐trained females during the early follicular phase utilizing a randomized, double‐blind, placebo‐controlled, crossover design. Fifteen females (29.8 ± 4.0 years, 63.8 ± 5.5 kg [mean ± SD]) ingested caffeine or placebo 60 minutes before completing a test battery separated by 72 hours. One‐repetition maximum (1RM), repetitions to failure (RTF) at 60% of 1RM, was assessed in the squat and bench press. Maximal voluntary contraction torque (MVC) and rate of force development (RFD) were measured during isometric knee extensions, while utilizing interpolated twitch technique to measure voluntary muscle activation. Maximal power and jump height were assessed during countermovement jumps (CMJ). Caffeine metabolites were measured in plasma. Adverse effects were registered after each trial. Caffeine significantly improved squat (4.5 ± 1.9%, effect size [ES]: 0.25) and bench press 1RM (3.3 ± 1.4%, ES: 0.20), and squat (15.9 ± 17.9%, ES: 0.31) and bench press RTF (9.8 ± 13.6%, ES: 0.31), compared to placebo. MVC torque (4.6 ± 7.3%, ES: 0.26), CMJ height (7.6 ± 4.0%, ES: 0.50), and power (3.8 ± 2.2%, ES: 0.24) were also significantly increased with caffeine. There were no differences in RFD or muscle activation. Plasma [caffeine] was significantly increased throughout the protocol, and mild side effects of caffeine were experienced by only 3 participants. This study demonstrated that 4 mg·kg−1 caffeine ingestion enhanced maximal strength, power, and muscular endurance in resistance‐trained and caffeine‐habituated females during the early follicular phase, with few adverse effects. Female strength and power athletes may consider using this dose pre‐competition and ‐training as an effective ergogenic aid.

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• Risvang, Linn Christin; Strøm, Vegard; Dijk, Jan-Willem van; Rice, Hannah; Sandbakk, Øyvind Bucher & Bovim, Lars Peder Vatshelle [Vis alle 10 forfattere av denne artikkelen] (2025). Investigating the Effects of a High-Load Resistance Training Program on Bone Health in Wheelchair Users (the BoneWheel Study): Protocol for a Randomized Controlled Trial. doi: 10.2196/70125. Fulltekst i vitenarkiv Vis sammendrag

  Background: Low mechanical loading of the bones of wheelchair users leads to low bone mineral density (BMD) and increased risk of bone fractures and associated complications. High-load resistance training of the upper body is one way to achieve mechanical loading of the lumbar spine and the hip bones. In addition, maintaining good nutritional status with key nutrients for bone remodeling, that is, vitamin D and calcium, is important for bone accrual. Objective: This study aims to investigate the effect of 24 weeks of high-load resistance training combined with nutritional optimization on lumbar spine BMD. Secondary objectives are to investigate the effects of the intervention on (1) bone and physical health parameters, such as bone turnover blood markers, nutritional status, body composition, and maximal muscular strength, as well as (2) exercise motivation and mental health. Methods: In this randomized controlled trial, we aimed to include 60 wheelchair users with nonprogressive impairments. Participants were randomly allocated to 24 weeks of either (1) high-load resistance training and nutrition optimization or (2) nutrition optimization only, stratified by sex and sport activity status. The training program consisted of 3 weekly sessions comprising 6 exercises periodized in low-, moderate-, and high-load phases. The nutritional optimization aimed to ensure sufficient intake of protein, vitamin D, and calcium. BMD and body composition; maximal muscular strength; and nutritional, physical, and mental health status were assessed at baseline, midpoint, and postintervention visits. Furthermore, follow-up assessments of a subgroup were conducted at 6 to 18 months after the intervention. This protocol was approved by the Regional Committee for Medical and Health Research Ethics South-East, Norway. Results: Recruitment occurred between November 2022 and 2023. A total of 68 wheelchair users were screened for eligibility, of whom 45 (66%) were enrolled and allocated to one of the study groups (n=24, 53% training group; n=21, 47% control group). At the midpoint and postintervention visits, 36 (n=17, 47% and n=19, 53%, respectively) and 33 (n=14, 42% and n=19, 58%, respectively) participants were assessed, respectively. Analysis of the data collected at the screening visit commenced in spring 2024, while analyses of data collected at the baseline and retest visits began in autumn 2024. Publication of the results of this study is expected by the end of 2025. Conclusions: This protocol presents the first randomized controlled trial of a high-load resistance training intervention in wheelchair users, focusing on bone, physical, and mental health. The results will contribute to new knowledge in exercise science for this population and generate novel hypotheses for future studies.

• Risvang, Linn (2026). From Risk to Response: Musculoskeletal Health of Wheelchair Users and Benefits of High-load Resistance Training: Results from the ‘BoneWheel’ Study. Norges idrettshøgskole. ISSN 9788250206489. Fulltekst i vitenarkiv Vis sammendrag

  Background: Wheelchair users are at increased risk of low bone mineral density (BMD), fragility fractures, and reduced lean mass due to chronic mechanical off-loading of the lower limbs, compounded by diagnosis-specific, nutritional, and endocrine factors. Existing literature on bone health in this population is dominated by studies in male individuals with spinal cord injury (SCI), often conducted in clinical or rehabilitation settings, and evidence from long-term, scalable exercise interventions remain limited. In ambulatory populations, high-load resistance training is an effective strategy to improve or preserve BMD, but whether similar principles can be applied to non-ambulatory wheelchair users is unknown. Aims: The overall aim of this thesis was to investigate musculoskeletal health in adult wheelchair users, with particular emphasis on bone health and the potential of high-load resistance exercise as an intervention strategy. Specifically, the thesis aimed to: 1. Describe and compare BMD in sports-active and non-sports-active wheelchair users (Paper I), 2. Investigate the effects of 24 weeks of high-load upper body resistance exercise combined with nutritional optimisation on BMD and bone turnover markers (BTMs), compared with nutrition optimisation alone (Paper II), and 3. Investigate concurrent effects of the intervention on muscle strength and lean mass responses (Paper III). Methods: This doctoral thesis is based on the BoneWheel study and comprises one crosssectional study and one multi-centre, single-blind randomised controlled trial (RCT). Adult wheelchair users with non-progressive physical impairments were recruited across three Norwegian study centres. BMD was assessed using dual-energy X-ray absorptiometry (DXA), with additional precision assessments conducted specifically in wheelchair users. Nutritional status, BTMs, hormonal markers, muscle strength (dynamic and isometric), lean mass, and functional independence were assessed. The intervention consisted of a 24-week high-load resistance training programme targeting the upper body and axial skeleton, delivered as partially supervised at the study centres, and mainly as unsupervised in commercial fitness centres. Both Training and Control group participants were provided with individualised nutritional optimisation of energy, protein, vitamin, and calcium intake. Statistical analyses were conducted using regression-based and mixed-effects models following intention-to-treat principles. Results: The cross-sectional analyses revealed an extremely high prevalence of low BMD at the hip and femoral neck (77-81%) among wheelchair users, which was not associated with sports participation. While sports-active individuals showed indications of higher lumbar spine BMD, no adjusted differences in mean BMD were observed between sports-active and non-sportsactive participants. Functional mobility and impairment characteristics were more strongly associated with BMD than sports participation per se. In the RCT, the resistance exercise intervention did not result in significant group-level improvements in BMD at lumbar spine, hip or femoral neck compared to nutrition optimisation alone. BTMs showed small, directionally favourable changes, but these did not translate into significant structural adaptations in BMD within the 24-week period. In contrast, the intervention elicited substantial and robust improvements in maximal muscle strength (12-22% across exercises) and site-specific increases in arm lean mass (4%). Conclusions: This thesis demonstrates that adult wheelchair users exhibit pronounced, sitespecific skeletal vulnerability, particularly at the hip and femoral neck, regardless of sports participation. While high-load resistance exercise combined with nutrition optimisation effectively improves muscle strength and localised lean mass outcomes, it appeared unable to provide a sufficient osteogenic stimulus to induce measurable BMD adaptations within the period and loading profile studied. These findings highlight a fundamental challenge in bone health management for wheelchair users: the individuals at greatest risk of hip fragility are also those least able to generate the osteogenic stimulus required to elicit bone adaptation. Future strategies may require more targeted, hip-specific loading approaches, longer intervention durations, or combined exercise and pharmacological interventions. Nevertheless, high-load resistance training remains valuable and scalable strategy for improving physical capacity and functional health in this population with our findings demonstrating that high-load resistance training is attainable, safe, and effective for improving neuromuscular outcomes in wheelchair users.

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