Effect of Arm Pull Distance and Duration on Performance in Butterfly Style Race

The aim of this study was to investigate the effects of stroke length and stroke cycle duration on swimming speed in female swimmers in the short-distance butterfly event. Seventy-two volunteer female swimmers from Istanbul who participated in a 50 m butterfly swimming competition were included in the study. The participants had a mean age of 12.78 ± 0.30 years, a mean training experience of 3.37 ± 0.69 years, a mean height of 1.57 ± 0.08 m, a mean arm span of 1.58 ± 0.07 m, a mean body mass of 46.19 ± 0.07 kg, a mean body mass index of 22.76 ± 2.75 kg/ m2, and a mean 50 m butterfly time of 38.69 ± 3.94 seconds. The swimmers’ performances during the competition were recorded from start to finish using two synchronized cameras placed poolside. Video recordings were analyzed with Kinovea 2023.1.2 software to determine underwater ascent distance and time, first and second 25 m split times, stroke count, stroke duration, and stroke length. The data were normally distributed and analyzed using paired-samples t-tests and simple linear regression. Significant differences were found between the first and second 25 m phases in stroke mechanics and velocity parameters (p < .05). The results showed that 50 m swimming velocity was significantly predicted by 25 m velocity (R = .94, p = .001) and stroke cycle duration (R = −0.63, p = .001) in the first 25 m, and by 25 m velocity (R = 0.98, p = .001) and stroke cycle duration (R = −0.65, p = .001) in the second 25 m. The findings indicate that performance parameters differ significantly across the two race phases in short-distance butterfly events, and that especially the velocity and stroke duration in the second 25 m play a decisive role in determining the total 50 m performance. Therefore, training programs should emphasize stroke duration drills and exercises that enhance speed in the second half of the race.