The aim of this study was to investigate the swimming efficiency of youth swimmers in the start, swimming, finish phases of short distance (50 meter) backstroke races. A total of 152 male swimmers who participated in the Long Course National Development Project races held in Istanbul, voluntarily participated in the study. One Canon camera with 25 fps was positioned to see the whole race. The 50-meter distance was analyzed in three sections: a) the start phase, which was the first 15-meter b) the swim phase between 15-meter, and 35-meter c) the finish phase, which was the last 15-meter. The swimmers' time, speed, stroke count, stroke rate, stroke length, stroke index, and SWOLF-Index were determined in these three phases. In the start phase, the distance and time (underwater distance and underwater time) obtained by the swimmers during their kicks between the start and underwater were not included. Data were analyzed by Repeated Measures ANOVA and Bonferroni post-hoc test in JASP 0.19.3 program. There were significant differences in the performance parameters of swimmers according to the start, swimming and finish phases of the 50-meter event (p0.05). Large effect sizes were observed for time, speed, stroke count, stroke rate, swim index, and SWOLF-Index values. In the short-distance backstroke race for male swimmers, significant differences in performance were observed according to different phases of the race. It was determined that after the first 15 meter, in addition to speed and time parameters, stroke mechanics, swimming index, and SWOLF-Index value also had a performance-determining effect.
Altan et al. (Fri,) studied this question.