Bjørn Harald Olstad

• Loisel, Camille; Olstad, Bjørn Harald; Guignard, Brice; Ljødal, Ingeborg; Gonjo, Tomohiro & Seifert, Ludovic (2026). Cycle-to-cycle kinematic variability management in short course 100 m breaststroke. Sports Biomechanics. ISSN 1476-3141. doi: 10.1080/14763141.2026.2733968. Full text in Research Archive
• Staub, Ilka; Brinkschulte, Michel; Costa, Aldo M.; Costa, Mario J.; Martelaer, Kristine De & D’Hondt, Eva [Show all 20 contributors for this article] (2026). Inter rater reliability of practical assessment criteria for aquatic literacy in children. Discover Education. 5(1). doi: 10.1007/s44217-026-01842-x. Full text in Research Archive
• Santos, Catarina C.; Garrido, Nuno D.; Costa, Aldo M.; Mekkaoui, Léa; Potdevin, François & Kwasna, Anna [Show all 19 contributors for this article] (2026). Test-Retest Reliability of the ALFAC Test Battery to Measure Aquatic Motor Skills Among Children Aged 6 to 12 Years. Measurement in Physical Education and Exercise Science. ISSN 1091-367X. doi: 10.1080/1091367X.2026.2713484. Full text in Research Archive
• Mekkaoui, Léa; Vogt, Tobias; Camporelli, Fabien; Costa, Aldo M.; Costa, Mário Jorge & Martelaer, Kristine De [Show all 21 contributors for this article] (2025). Improving Water Safety and Long-term Engagement in Aquatic Physical Activity: The Aquatic Literacy Framework. Journal of teaching in physical education. ISSN 0273-5024. doi: 10.1123/jtpe.2024-0244. Full text in Research Archive Show summary

  Young people worldwide are affected by two main health-related issues: physical inactivity and drowning accidents. Encouraging participation in aquatic physical activities in a safe way could address this dual concern. Aligning theoretical frameworks of physical literacy and water competencies could empower young people with key skills to engage safely and sustainably in aquatic environments. The aim of this theoretical paper is to provide a philosophical, ontological, and epistemological rationale for merging these two frameworks into a new concept: aquatic literacy. The multidimensional concept is presented and describes the intertwined physical, psychosocial, and cognitive domains, which provide a means to empower young people to safely enjoy aquatic opportunities and achieve individual health benefits. This new concept needs supportive empirical data, such as the level of individuals in each domain of aquatic literacy, to be a strong framework for guiding aquatic educators and stakeholders to better engage and protect people worldwide.

• Fermon, Louise; Potdevin, François; Andkjær, Søren; Bortoletto, Nico; Corsi, Mario & Costa, Mário J. [Show all 23 contributors for this article] (2025). Bridging the Gap in Physical Activity and Sport Among Women University Students: Motivational and Practical Insights for Effective Promotion. Women in Sport & Physical Activity Journal. ISSN 1063-6161. 33(1). doi: 10.1123/wspaj.2025-0015. Full text in Research Archive Show summary

  Women’s participation in physical activity (PA) and sport remains lower than that of men, with specific challenges persisting into young adulthood. This study aims to better understand the diverse engagement patterns and motivations of women university students in order to inform targeted, gender-sensitive approaches to PA and sport promotion. A survey was conducted among 2,071 women students aged 18–25 years ( M  = 20.01, SD  = 1.33) from 16 European universities. Principal component analysis and clustering techniques revealed two main participation styles: “free” (C1 and C2) and “organized” (C3 and C4). The “free” group preferred low-intensity, flexible activities, often self-directed, and supported by digital tools, while the “organized” group thrived in structured, socially supportive environments such as clubs or team sports with coaching. Motivational factors varied considerably: C1 participants did not prioritize a single motivational factor, C2 were primarily motivated by physical condition and appearance, while a combination of enjoyment, affiliation, and psychological well-being drove C3 and C4 participants. The study highlights the need for universities to offer diverse, flexible PA options that cater to different preferences, from autonomous activities facilitated by digital innovations to structured programs that promote social belonging and accountability. Universities can create supportive environments that encourage sustained PA and sport engagement by tailoring interventions to individual motivations and using inclusive communication strategies. These findings provide valuable insights for promoting active lifestyles among women university students and for advancing gender-sensitive approaches to PA and sport promotion.

• Gonjo, Tomohiro; Veiga, Santiago; Hermosilla-Perona, Francisco & Olstad, Bjørn Harald (2025). Variabilities in the stroking parameters during short course 50 m time trials in all four competitive swimming strokes. Scientific Reports. 15. doi: 10.1038/s41598-025-08519-9. Full text in Research Archive Show summary

  Abstract The purpose of this study was to identify intra- and inter-individual variabilities during short course 50 m sprints. Swimming velocity ( SV ), stroke frequency ( SF ), and stroke length ( SL ) for each stroke cycle in 189 male and 160 female swimmers’ 50 m time trials (with their specialised stroke) were analysed. The inter-individual variability for each kinematic variable was analysed using the inter-individual standard deviation of the Gaussian Process regression. Intra-participant variability was analysed using k-means clustering with kinematic data extracted from the first, mid-, and last strokes. In all strokes and both sexes, swimmers showed large inter-individual kinematic variabilities at the first and last strokes, which justified the need to separate these strokes from the clean-swimming segment in race analyses. Intra-individual kinematic patterns were categorised into four clusters with different within-lap SV patterns. Particularly, many front crawl and backstroke swimmers showed a faster velocity in mid-pool than in the transition, while many butterfly swimmers showed the fastest SV in the transition. This might suggest a greater difficulty in the transition technique in alternating strokes than in butterfly. Race analyses should focus on not only the overall trend but also individual variabilities to investigate the swimmers’ behaviour during swimming races.

• Mekkaoui, Léa; Potdevin, François; Derigny, Thibaut; Gandrieau, Joseph; Staub, Ilka & DeMartelaer, Kristine [Show all 11 contributors for this article] (2025). Towards a Consensus on the development of the Aquatic Curricula Analysis Tool using an Ecosystem Approach: A Delphi Method. Physical Activity Review. 13(1), p. 141–155. doi: 10.16926/par.2025.13.13. Full text in Research Archive
• Keller, Sebastian; Olstad, Bjørn Harald & Wahl, Patrick (2024). Lower and upper extremity contributions to propulsion and resistance during semi-tethered load-velocity profiling in front crawl swimming. Journal of Sports Sciences. ISSN 0264-0414. 42(3), p. 215–221. doi: 10.1080/02640414.2024.2326347. Full text in Research Archive
• Olstad, Bjørn Harald; Hunger, Lea; Ljødal, Ingeborg; Ringhof, Steffen & Gonjo, Tomohiro (2024). The relationship between load-velocity profiles and 50 m breaststroke performance in national-level male swimmers. Journal of Sports Sciences. ISSN 0264-0414. 42(16), p. 1512–1518. doi: 10.1080/02640414.2024.2397234. Full text in Research Archive Show summary

  This study investigated the relationships between load-velocity profiling and 50 m breaststroke performance. Twenty-seven male swimmers qualified for the national championship participated and performed a 50 m breaststroke trial with a multicamera system. The total race time (t50 m), forward velocity during surface swimming (v50 m), stroke length, and stroke frequency were obtained from the automatic post-processing of the system. Afterwards, the participants performed semi-tethered swimming with three external loads using a robotic resistance device. The average velocity from three stroke cycles was plotted as a function of the corresponding load. The theoretical maximum velocity (v0) and load (L0), L0 normalized to body mass, steepness of the regression line (slope), and active drag (AD) were calculated. The main findings were moderate to large correlations of two 50 m race variables (t50 m and v50 m) with v0, L0, and AD (t50 m range: r = -.444 to r = -.619, p = .020 to p = .001), (v50 m range: r = .451 to r = .568, p = .018 to p = .002). This shows the importance of applying maximum propulsive force to achieve high swimming performance and that load-velocity profiling is an indicator of 50 m breaststroke performance. Load-velocity measurements over time can also monitor velocity, strength, and drag-minimizing abilities, explaining performance changes and training effects.

• Gonjo, Tomohiro; Vitazka, Maria; Ljødal, Ingeborg & Olstad, Bjørn Harald (2024). The Load-Velocity Slope Is an Indicator of the Active Drag in all Competitive Swimming Strokes. Medicine & Science in Sports & Exercise. ISSN 0195-9131. 57(1), p. 115–122. doi: 10.1249/MSS.0000000000003551. Full text in Research Archive Show summary

  Introduction: Active drag in swimming is a critical variable that affects swimmers’ performance as well as the physiological load, but it is challenging for practitioners to assess this variable. This study aimed to assess if the load-velocity profiling method can be used as an indicator of active drag. Methods: A total of 419 swimmers performed three semi-tethered swimming trials in their speciality among the four competitive strokes with different external loads. Linear regression between external load and swimming velocity, as well as the external load relative to the body mass and swimming velocity, were established. The active drag and drag coefficient of each swimmer were calculated using a velocity perturbation method. Conclusions: These results indicate that the absolute load-velocity slope is a strong indicator of the active drag, and the relative slope is useful when indirectly assessing the drag coefficient.

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