Gender-related differences in kinematic parameters of the start and performance in a 50m breaststroke swimming

Introduction: In swimming, the competitions are divided by age categories, with each swimming event beginning at the start. For optimal improvements in swimming performance in the sprint events, the performance at the start and during swimming in each age category should be analyzed. Aim: The aim of our study is to show the differences in kinematic parameters of the start and performance in the sprint event of 50 m breaststroke from the perspective of gender in different age groups at international competitions organized in Slovakia. Materials and Methods: The females were categorized by age into K3 (2010-2011; n=36; 282 WA points), K2 (2008-2009; n=26; 409 WA points) and K1 (2007 and older; n=34; 503 WA points) groups. Males were categorized into K3 (2009-2010; n=27; 265 WA points), K2 (2007-2008; n=33; 372 WA points) and K1 (2006 and older; n=39; 207 WA points) groups. We used SwimPro cameras and Dartgish software to monitor kinematic parameters in the above-water, underwater, and swim phases. The parameters monitored were block time (BT), time (FT), and length (FD) of flight, time (UWT) and length (UWD) underwater, swim time (ST) and distance (SD) to 15 m, time to 15 m (T15), 25 m (T25), and 50 m (T50) distance. Data were tested by Shapiro-Wilk, Kruskal-Wallis ANOVA, and Mann-Whitney U test in Statistica software (version 13.5). Results: Statistically significant differences (p<0.01) in females were found in the above-water phase in BT, FT, and FD between K3 and K1. The underwater phase in UWT showed differences between K3 to K1, K2 to K1 whereas for UWD - between K3 and K2 and between K2 and K1. For T15 and T25, there were differences (p<0.01) between all categories, but in the final time (T50), the differences occurred between K3 and K2 and between K3 and K1. In males, there was a significant difference in the above-water phase between K3 and K1 and between K2 and K1. In UWD, ST, SD, T15, T25, and T50, there were significant differences between all categories. Differences (p>0.01) between males and females by category in the above-water phase were measured in FT (K1) and FD (K2, K1). In the underwater phase, the differences were found in UWT (K2) and UWD (K1). For T15, T25, and T50, significant differences were shown in all categories. Conclusions: The kinematic analysis revealed differences not only in the start phases and the 50 m breaststroke swimming in the male and female categories but also between genders. Differences in swimming performance may be due to performance at the start and therefore more attention should be paid to the start phases in the different categories of swimmers.