ON PERFORMANCE DIFFERENCES IN CHILDREN
Sex-based differences in swimming performance in 10-years-old-and-under athletes in short course national competition
https://onlinelibrary.wiley.com/doi/10.1002/ejsc.12237
Gregory A Brown, Brandon S Shaw & Ina Shaw
Published 7th December 2024
Conclusion
The present data indicates that prepubertal males swim 1.16%–2.63% significantly faster than females in the 50 yd (45.7), 100 yd (91.4), and 200 yd (182.9 m) freestyle, 100 yd backstroke, 50 yd breaststroke, 100 yd butterfly, and 100 and 200 yd IM, but not in the 500 yd (457.2 m) freestyle, 50 yd butterfly, 100 yd breaststroke, or 50 yd backstroke (although the differences in the 50 yd backstroke approached significance). The present data do not explain why there are sex-based differences in some, but not all, of these events. Based on the present and previous data indicating that prepubertal males swim faster than prepubertal females in most events, there seems to be little justification to eliminate sex segregated competition in youth swimming.
Furthermore, this study serves as a valuable contribution to our comprehension of the intricate interplay between sex differences and swimming performance in prepubertal children. Although further research is imperative to refine and expand upon our current understanding, the findings presented here underscore the significance of considering sex-specific factors in the assessment of swimming performance in prepubertal children. Acknowledging and investigating these differences not only advances our knowledge in sports science but also holds potential implications for training strategies tailored to individual needs. As we delve deeper into this realm, the multifaceted nature of sex-related influences on swimming performance in prepubertal children becomes increasingly apparent, allowing for more targeted and effective approaches in the pursuit of athletic safety, inclusion, and excellence.
Point made by author on twitter:
"In 8 out of 12 events boys swam significantly faster than girls and there were no events where girls were significantly faster. More evidence that sex matters in sports!"
https://x.com/BrowngaGreg/status/1865528288644382872
This is one of the main points:
Males were 1.16%–2.63% faster (p < 0.05; effect sizes 0.376–0.596) than females in the 50 yards (yd; 45.7 m), 100 yd (91.4 m), and 200 yd (182.9 m) freestyle, 100 yd backstroke, 50 yd breaststroke, 100 yd butterfly, and 100 and 200 yd IM. There were no significant sex-based differences in the 500 yd (457.2 m) freestyle, 50 yd backstroke, 100 yd breaststroke, or 50 yd butterfly. The individual fastest time for a female was faster than for a male in the 50, 100, and 500 yd freestyle, 50 and 100 yd backstroke, 50 and 100 yd butterfly, and 100 yd IM.
Although in eight out of 12 events the individual fastest times were from females, in eight out of 12 events the average male times were significantly faster.