Alfonso Trinidad

Despite the increasing importance of the underwater segment of start and turns in competition and its positive influence on the subsequent surface swimming, there is no evidence on how the transition from underwater to surface swimming should be performed. Therefore, the aim of the present study was to examine the role of segmental, kinematic and coordinative parameters on the swimming velocity during the pre-transition and transition phases. A total of 30 national male swimmers performed 4 × 25 m (one each stroke) from a push start at maximum velocity while recorded from a lateral view by two sequential cameras (50 Hz), and their kinematic and coordinative swimming parameters were calculated by means of two-dimensional direct linear transformation (DLT) algorithms. Unlike pre-transition, backward regression analysis of transition significantly predicted swimming velocity in all strokes except breaststroke (R² ranging from 0.263 in front crawl to 0.364 in butterfly). The inter-limb coordination was a predictor in butterfly stroke (p = 0.006), whereas the body depth and inclination were predictors in the alternate strokes (front crawl (p = 0.05) and backstroke (p = 0.04)). These results suggest that the body position and coordinative swimming parameters (apart from kicking or stroking rate and length) have an important influence on the transition performance, which depends on the swimming strokes.

The objective of the present study was to analyze (based on gender and the style of swimming) the kinematic parameters of the transition phase between underwater swimming and surface swimming after the push-off start in competitive national swimmers. Seventy-four swimmers participating in the Spanish Swimming Championships were filmed and analyzed by DLT-2D photogrammetry during the start with the push-off in crawl, backstroke and butterfly styles. Between genders there were small differences in the distance and speed of transition. The male swimmers travelled greater distances (0.84 ± 0.04 vs. 0.66 ± 0.04 m, η2 = 0.05, F = 10.34, p < 0.001) and they were faster (1.59 ± 0.03 vs. 1.38 ± 0.03 m/s, η2 = 0.08, F = 19.54, p < 0.001) in the transition phase than female swimmers. Among styles there were greater differences in time (η2 = 0.47, F = 94.50, p < 0.001) and transition distance (η2 = 0.38, F = 67.08, p < 0.001), than in speed (η2 = 0.05, F = 5.63, p < 0.001). During the backstroke push-off, swimmers spent more time (0.88 ± 0.04 s) and distance (1.17 ± 0.05 m), this being the slowest style (1.37 ± 0.04 m/s). In butterfly, athletes used less time (0.26 ± 0.03 s) and distance (0.39 ± 0.05 m) whereas crawl was the fastest of all (1.57 ± 0.04 m/s). These results allow the phase of transition from underwater to surface swimming to be characterized and to provide useful data for competitive swimmers and coaches to improve performance.

The goal of this research was to review the experimental studies that have analyzed the influence of “high-speed swimsuits” on sports performance up to the appearance of the model “Jammer” in competitive swimmers. The design was a review following PRISMA Methodology, in which 43 studies were reviewed of a total of 512. Several searches were conducted in electronic databases of the existing research in this field (Google Scholar, Dialnet, Web of Sciences, and Scopus). The only studies excluded were those that reviewed the effects with neoprene and tests with triathletes. The studies that were included were published and peer-reviewed from 1999 to 2018 in which the effect of high-speed swimsuits was analyzed. The results showed the possible effects that high-speed swimwear can have in relation or not to competitive performance, biomechanical, physiological and psychological factors, flotation, drag, the material and the design until the introduction of the model “Jammer.” As conclusions, the lack of consensus due to the variety of fields of study means that improvements in competitions are still not clarified. In addition, the change in the rules may have effects on swimmers even though they have beaten records with other swimwear. Finally, the debate concerning whether medals were won unfairly or not is proposed.