Bjørn Harald Olstad

• 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. doi: 10.1080/02640414.2024.2326347.
• Ljødal, Ingeborg; Olstad, Bjørn Harald & Pensgaard, Anne Marte (2023). Motives, Motivation, and Motivational Climate of Young Norwegian Swimmers, and their Parents’ Belief. Scandinavian Sport Studies Forum. ISSN 2000-088X. 14, p. 151–175. Full text in Research Archive Show summary

  Motivation is important for enjoyment, skill development, and persistence in swimming. The quality and direction of motivation is influenced by a swimmer’s perceived motivational climate, which is created by coaches and parents. The theoretical framework combines self-determination theory and achievement goal theory, to analyse the motives and motivation of swimmers and the influence of social climate on their motivation. Parents greatly impact young children’s participation motives and motivation, but few studies ask parents about their beliefs about their child’s motives and motivation. Online questionnaires were distributed to 11-13-year-old swimmers and their parents. The children responded to five questionnaires measuring sport participation motives, self-determined motivation, goal orientation, coach-initiated motivational climate, and parent-initiated motivational climate. Parents responded to the first two indicating their belief in their child’s motives and self-determined motivation. Results showed that swimmers are predominantly intrinsically motivated, task oriented, and perceive a mastery climate from coaches and parents. Parent’s belief of their child’s motives and self-determined motivation matched the swimmers’ self-reported motives and self-determined motivation. Coaches are shown to impact self-determined motivation and goal orientations to a greater extent than parents. In conclusion, coaches and parents should aim to maintain their current focus on mastery and enjoyment. This can ensure longer participation in and greater enjoyment of the sport, which would lead to further development and improved performance.

• Wettengl, Christina; Karlsson, Rebecca Vilde Martine Krohn; Olstad, Bjørn Harald & Gonjo, Tomohiro (2023). Load-Velocity Profile and Active Drag in Young Female Swimmers: An Age-Group Comparison. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 19(1), p. 44–52. doi: 10.1123/ijspp.2022-0213. Full text in Research Archive
• Szczepan, Stefan; Wróblewska, Zofia; Klich, Sebastian; Michalik, Kamil; Gonjo, Tomohiro & Olstad, Bjørn Harald [Show all 7 contributors for this article] (2023). Reliability of a semi-tethered front crawl sprint performance test in adolescent swimmers. Frontiers in Physiology. ISSN 1664-042X. 14. doi: 10.3389/fphys.2023.1260346. Full text in Research Archive
• Barbosa, Augusto C.; Araújo, Leonardo Tomasello; Leis, Leonardo Vecchi; Lourenço, Thiago Fernando; Barroso, Renato & Gonjo, Tomohiro [Show all 9 contributors for this article] (2023). The gold rush in para swimming: changes in the speed curve of a visually impaired world and paralympic champion–a case study. Sports Biomechanics. ISSN 1476-3141. doi: 10.1080/14763141.2023.2221680. Full text in Research Archive Show summary

  This case study examined the association between 50 m freestyle and speed curve parameters of a world-class Paralympic swimmer and analysed the changes in speed curves and their frequency components across her performance levels. From 2018 to 2021, a visually impaired female swimmer (26.59 s in 50 m freestyle, S12 class) underwent 22 tests to obtain instantaneous speed synchronised with video recording. She regularly performed 50 m freestyle in competitions and time trials. The fast Fourier transformation method converted the speed signal into frequency domains and determined the relative contribution of the harmonics with two maxima and minima (H2, arms actions) and six maxima and minima (H6, legs actions). The functional paired t-test compared the speed curves at the beginning (PRE) and end (POST) of the analysed period. The 50 m freestyle time correlated with average speed (r = −0.50, p = 0.02). The contribution of H6 increased in the first year and remained large, whereas the contribution of H2 was lower throughout the whole period. POST was faster than PRE in five moments that coincide with the downward leg kick moments. These changes allowed her to stay longer at the upper part of the curve and improve performance over time.

• Gonjo, Tomohiro; Olstad, Bjørn Harald; Štastný, Jan; Conceição, Ana & Seifert, Ludovic (2023). Intra- and inter-individual variability in the underwater pull-out technique in 200 m breaststroke turns. PLOS ONE. ISSN 1932-6203. 18(3). doi: 10.1371/journal.pone.0283234. Full text in Research Archive Show summary

  The purpose of the present study was to investigate the intra- and inter-individual variability in arm-leg coordination during the underwater phase of the turn segment in 200 m breaststroke. Thirteen male swimmers were recruited and performed a 200 m breaststroke in a pre-calibrated 25 m pool. Sub-phases during the underwater segment were obtained using a notational analysis, and the mean velocity, displacement and duration during each sub-phase were obtained. A hierarchical cluster analysis (HCA) was performed using the analysed variables in all phases to identify inter-individual variability and random intra-individual variability. In addition, a linear mixed model (LMM: lap as a fixed effect and the participant as a random effect) was conducted to investigate systematic intra-individual variability. HCA identified three coordination patterns that were distinguished by the timing of the dolphin kick relative to the arm pull-out and the duration of the glide with arms at the side. All swimmers except one performed the arm pull-out after the dolphin kick. Nine swimmers maintained one coordination pattern, but other swimmers switched their coordination during the trial, particularly by shortening the duration of the glide with arms at the side. LMM showed a linear decrease (from the first to the last turn) in the time gap between the end of the dolphin kick and the start of the arm pull-out (a glide with the streamlined body position; F = 9.64, p = 0.034) and the glide duration with the arms at the side (F = 11.66, p = 0.015). In conclusion, both inter- and intra-individual variabilities during the underwater phase were evident in 200 m breaststroke turns, which were categorised into three patterns based on the timing of the dolphin kick and the duration of glides.

• Gonjo, Tomohiro; Polach, Marek; Olstad, Bjørn Harald; Romann, Michael & Born, Dennis-Peter (2022). Differences in Race Characteristics between World-Class Individual-Medley and Stroke-Specialist Swimmers. International Journal of Environmental Research and Public Health (IJERPH). ISSN 1661-7827. 19(20). doi: 10.3390/ijerph192013578. Full text in Research Archive Show summary

  The purpose of the present study was to investigate differences between world-class individual medley (IM) swimmers and stroke-specialists using race analyses. A total of eighty 200 m races (8 finalists × 2 sexes × 5 events) at the 2021 European long-course swimming championships were analysed. Eight digital video cameras recorded the races, and the video footage was manually analysed to obtain underwater distance, underwater time, and underwater speed, as well as clean-swimming speed, stroke rate, and distance per stroke. Each lap of the IM races was compared with the first, second, third, and fourth laps of butterfly, backstroke, breaststroke, and freestyle races, respectively. Differences between IM swimmers and specialists in each analysed variable were assessed using an independent-sample t-test, and the effects of sex and stroke on the differences were analysed using a two-way analysis of variance with relative values (IM swimmers’ score relative to the mean specialists’ score) as dependent variables. Breaststroke specialists showed faster clean-swimming speed and longer distance per stroke than IM swimmers for both males (clean-swimming speed: p = 0.011; distance per stroke: p = 0.023) and females (clean-swimming speed: p = 0.003; distance per stroke: p = 0.036). For backstroke and front crawl, specialists exhibited faster underwater speeds than IM swimmers (all p < 0.001). Females showed faster relative speeds during butterfly clean-swimming segments (p < 0.001) and breaststroke underwater segments than males (p = 0.028). IM swimmers should focus especially on breaststroke training, particularly aiming to improve their distance per stroke.

• Born, Dennis-Peter; Schönfelder, Michel; Logan, Oliver; Olstad, Bjørn Harald & Romann, Michael (2022). Performance Development of European Swimmers Across the Olympic Cycle. Frontiers in Sports and Active Living. ISSN 2624-9367. 4. doi: 10.3389/fspor.2022.894066. Full text in Research Archive Show summary

  The aims of the study were to (1) quantify the performance development of race times and key performance indicators of European swimmers across the last Olympic cycle (from 2016 to 2021) and (2) provide reference values for long-course swimming pool events for both sexes from 50 m to 1,500 m including butterfly, backstroke, breaststroke, freestyle, and individual medley. Individual events from the 2016 and 2021 European swimming championships were included. Specifically, 246 men (age: 24.2 ± 3.4 years, FINA points: 890 ± 40) and 256 women races (age: 24.2 ± 4, FINA points: 879 ± 38) of the finalists were recorded and key performance indicators and split times analyzed. Performance differences in finalists of the 2016 and 2021 European championships were determined by an independent t-test and Cohen's d effect size. Reference values were retrieved from 2021 European championship finalists and are provided for all key performance indicators. Race times improved significantly (P < 0.05) or showed moderate (d = 0.5–1) to large effect sizes (d > 1) in 14 (men) and 6 (women) out of 16 events. Improvements were primarily evident in 100 m and 200 m events for males, as well as BR and sprint events for female swimmers. While start times improved in 15 (men) and 14 (women) events, turn times remained inconclusive in both sexes. Generally, breakout distances increased. Clean swimming velocities were faster in 12 (men) and 5 (women) events. In particular, for alternating swimming strokes, i.e., backstroke and freestyle, effect sizes indicated improved swimming efficiency with an inverse relationship between reduced stroke rate and increased distance per stroke. Coaches and performance analysts may use the present reference values as comparative data for race analyses and to specifically prepare swimmers for the various race sections. Data on the performance development should be used to analyze swimmers' potential and set goals for the various events and the next Olympic cycle.

• Gonjo, Tomohiro & Olstad, Bjørn Harald (2022). Reliability of the active drag assessment using an isotonic resisted sprint protocol in human swimming. Scientific Reports. ISSN 2045-2322. 12. doi: 10.1038/s41598-022-17415-5. Full text in Research Archive Show summary

  The purpose of the presents study was to investigate the reliability of the active drag (Da) assessment using the velocity perturbation method (VPM) with different external resisted forces. Eight male and eight female swimmers performed 25 m sprints with five isotonic loads (1–2–3–4–5 kg for females; 1–3–5–7–9 kg for males), which were repeated twice on different days. The mean velocity and semi-tethered force were computed for each condition, and the free-swimming maximum velocity was estimated with load-velocity profiling. From the obtained variables, Da at the maximum free-swimming condition was calculated using VPM. Absolute and typical errors and the intra-class correlation (ICC) were calculated to assess test–retest reliability. 95% confidence interval (95% CI) lower bound of ICC was larger than 0.75 in 3, 4 (females only) and 5 kg trials in both sexes (corresponding to 37–60 N additional resistance; all p < 0.001), which also showed small absolute and relative typical errors (≤ 2.7 N and ≤ 4.4%). In both sexes, 1 kg load trial (16–17 N additional resistance) showed the lowest reliability (95% CI of ICC; − 0.25–0.83 in males and 0.07–0.94 in females). These results suggested that a tethered force of 37–60 N should be used to assess Da using VPM.

• Barbosa, Augusto C.; Barroso, Renato; Gonjo, Tomohiro; Rossi, Marcel M.; Paolucci, Leopoldo A. & Olstad, Bjørn Harald [Show all 7 contributors for this article] (2021). 50 m freestyle in 21, 22 and 23 s: What differentiates the speed curve of world-class and elite male swimmers? International Journal of Performance Analysis in Sport. ISSN 2474-8668. doi: 10.1080/24748668.2021.1971509. Full text in Research Archive Show summary

  We examined the association between 50 m freestyle performance (50FS) and average speed (AS), peak speed (PS), minimum speed (MS) and intracyclic speed variation (ISV) and compared the speed curves from swimmers with different performance levels using functional analysis of variance (FANOVA). Fourteen male swimmers (50FS: 22.50 ± 0.58 s) performed a maximal sprint with a speedometer and AS, PS, MS, and IVV were assessed for correlational analysis. 50FS were obtained in official competitions. Swimmers were assigned to three groups based on actual 50FS: G21 (n = 2, 21.99 ± 0.04 s), G22 (n = 6, 22.82 ± 0.10 s) or G23 (n = 6, 23.55 ± 0.18 s). FANOVA compared the average curves. 50FS correlated to AS (r = −0.781, p = 0.001) and PS (ρ = −0.766, p = 0.001), but not to MS (r = −0.185, p = 0.527) or IVV (r = −0.323, p = 0.259). FANOVA showed that faster swimmers achieved higher PS and stayed longer at the upper part of the curve. 50FS performance is related to average and peak speed assessed with the speedometer. Swimmers should seek techniques to maintain the speed at the upper part of the curve as long as possible.

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