Sex differences in youth elite swimming.

Abstract

BackgroundThe timing and magnitude of sex differences in athletic performance during early human development, prior to adulthood, is unknown.ObjectiveTo compare swimming velocity of boys and girls for all Olympic-length freestyle swimming events to determine the age of divergence in swimming performance.MethodsWe collected the all-time top 100 U.S. freestyle swimming performance times of boys and girls age 5 to 18 years for the 50m to 1500m events.ResultsSwimming performance improved with increasing age for boys and girls (pConclusionThe top 5 girls demonstrated faster swimming velocities and the 10th-50th place girls demonstrated similar swimming velocities than boys (until ~10 years). After age 10, however, boys demonstrated increasingly faster swimming velocities than girls until 17 years. Collectively, these data suggest girls are faster, or at least not slower, than boys prior to the performance-enhancing effects of puberty.