Objectives The primary goal was to examine the influence of early specialization on the performance of senior elite swimmers. Secondly, to provide information about the influence of swim style, distance, sex, status, country, years of high-level competition (YHLC) and age in swimmer’s performance. Design Data was obtained from International Federation of Swimming (FINA) regarding the participants 2006–2017 of junior and senior World Championships (WCs). The final filtered database included 4076 swimmers after removing those participating only in junior WCs. Method Cramer V coefficient, double and triple-entry tables were used to measure the relationship between the positions occupied in junior and senior phases. A One-Way ANOVA analysis was used to explain the variables time and rank between swimmers who participated in junior and senior WC or just in senior in all the distances and swim styles (SS). A univariate general linear model (GLM) was used to examine the association between time/rank and category (swimmers that participated previously in junior WC or not); YHLC; country; status (highest finishing position: final/semi-final/heats) and age. Results Significant differences (p < .001) were found in the GLM, with Rank as dependent variable, for all the variables. Showing that swimmers that participated previously in junior categories obtained greater results in all the interactions, except in 1500m freestyle. Significant differences (p < .001) were found between the variables position and YHLC, showing the variable position improvements as swimmers attended more WCs. Conclusion Competing in junior WC has a positive influence in achieve posteriori success in FINA WC. YHLC have a positive impact to achieve better positions.

The NIKE Vaporfly shoe was introduced in May 2017 as part of the original #Breaking2 Project (an event aimed to run the first marathon under 2 h). This new advanced shoe technology (NAST) changed the footwear design conception. The aim of this study was (i) to analyse the effect of NAST in men’s marathon performance, (ii) to analyse whether the changes in the environmental constraints (temperature and wind) and orography of the marathons, age and birthplace of the runners has changed from 2015 to 2019 and (iii) to analyse the impact of NAST on the historical 50 best performances. Data from top-100 men's marathon performances were collected in that timeframe. The shoes used by the athletes were identified (in 91.8% of the cases) by publicly available photographs. External and environmental conditions of each marathon and age and birthplace of the runners were also analysed. Marathon performances improved from 2017 onwards between 0.75 and 1.50% compared to 2015 and 2016 (p < 0.05). In addition, the improvement was greater in the upper deciles than in the lower ones (p < 0.001). Runners wearing NAST ran ~ 1% faster in marathon compared to runners that did not use it (p < 0.001). When conducting an individual analysis of athletes who ran with and without NAST, 72.5% of the athletes who completed a marathon wearing NAST improved their performance by 0.68% (p < 0.01). External and environmental conditions, age or birthplace of runners seems not to have influenced this performance improvement. NAST has had a clear impact on marathon performance unchanged in the environmental constraints (temperature and wind), orography, age, and birthplace of the runners but with differences between venues.

Purpose: The primary aim was to create a performance progression model of elite competitors in the World Swimming Championships from 2006 to 2017 for all strokes and distances. Secondly, to identify the influence of annual ratios of progression, ages of peak performance and junior status on success in senior competitions. Methods: Data regarding the participants of senior and junior World Championships (WCs) between 2006 and 2017 were obtained from FINA. The final filtered database, after removing those swimmers who just participated in junior WCs, included 4076. Statistical models were used to examine differences between the top senior swimmers (the top 30% best performances; T30) and lower level swimmers (the bottom 70% performances; L70) for minimum age (MA), progress (P) and best junior time (BJ). In order to identify the variables that contribute to reach the T30 group, a logistic regression (LR), stepwise LR and decision tree were applied. To analyze the effect of each variable separately, a simple LR (gross odds ratio) was performed. Ratio probabilities (OR) and 95% confidence intervals were calculated for each variable. Results: Swimmer's BJ and P were higher in the T30 group (p < 0.000). The decision tree showed the greatest explanatory capacity for BJ, followed by P. The MA had a very low explanatory capacity and was not significant in the LR. Conclusion: Swimmers with exceptional junior performance times, or have a high rate of progress are more likely to be successful at the senior WCs.

The underwater phase is perhaps the most important phase of the swimming start. To improve performance during the underwater phase, it is necessary to improve our understanding of the key variables affecting this phase. The main aim of this study was to identify key kinematic variables that are associated with the performance of an underwater glide of a swimming start, when performed at streamlined position without underwater undulatory swimming. Sixteen experienced swimmers performed 48 track starts and 20 kinematic variables were analysed. A multiple linear regression analysis was carried out to explore the relationship between glide performance (defined as glide distance) and the variables that may affect glide performance. Four variables in the regression model were identified as good predictors of glide distance: flight distance; average velocity between 5 m and 10 m; and maximum depth of the hip. The results of the present study help improve our understanding of underwater glide optimisation and could potentially facilitate improvement of overall start performance.

Evaluating force–velocity characteristics on dry-land is of the utmost importance in swimming, because higher levels of these bio-motor abilities positively affect in-water performance. However, the wide range of possible technical specializations presents an opportunity for a more categorized approach that has yet to be seized. Therefore, the aim of this study was to identify feasible differences in maximum force–velocity exertion based on swimmers’ stroke and distance specialization. To this scope, 96 young male swimmers competing at the regional level were divided into 12 groups, one for each stroke (butterfly, backstroke, breaststroke, and front crawl) and distance (50 m, 100 m, and 200 m). They performed two single pull-up tests, 5-min before and after competing in a federal swimming race. We assessed force (N) and velocity (m/s) exertion via linear encoder. There were no significant differences between pre-post maximum force–velocity exertions, despite the decreasing trend. Force-parameters highly correlated with each other and with the swimming performance time. Moreover, both force (t = −3.60, p < 0.001) and velocity (t = −3.90, p < 0.001) were significant predictors of swimming race time. Sprinters (both 50 m and 100 m) of all strokes could exert significantly higher force–velocity compared to 200 m swimmers (e.g., 0.96 ± 0.06 m/s performed by sprinters vs. 0.66 ± 0.03 m/s performed by 200 m swimmers). Moreover, breaststroke sprinters presented significantly lower force–velocity compared to sprinters specialized in the other strokes (e.g., 1047.83 ± 61.33 N performed by breaststroke sprinters vs. 1263.62 ± 161.23 N performed by butterfly sprinters). This study could provide the foundation for future research regarding the role of stroke and distance specializations in modeling swimmers’ force–velocity abilities, thus influencing paramount elements for specific training and improvement towards competitions.