Sex differences in youth elite swimming The time and the extent of sexual differences in sporting performance during early human development before adulthood are unknown. The idea of this study was the comparison of the swimming speed of boys and girls for all freestyle swimming events to determine the age of divergence of swimming performance. The 100 best US freestyle swimming times of boys and girls aged 5 to 18 years for the 50 m to 1500 m were collected. The swimming performance improved with increasing age for boys and girls to reach a plateaus that used in girls (15 years) in a younger age than in boys (17 years). Before the age of 10, the top 5 swimming recorder for girls were 3% faster than for the top boys. For places 10 to 50, however, there were no gender differences in the swimming benefit before the age of 10.For both the top 5 and 10th to 50th place, the gender performance difference increased from 10 years to the 17th year of life. For everyone, the gender-specific performance difference at the age of 18 was greater in the sprints (9.6%, 50-200 m) than in the long distances (7.1%, 400-1500 m). In addition, the sexual performance difference over the age and US ranking increased from 2.4% to the first place to 4.3% for the 100th place, indicating a lower power density in the girls than the boys. The annual participation, however, was the girls for all ages in the girls than in the boys. The top 5 girls showed faster swimming speeds and the girls on the 10th to 50th place showed similar swimming speeds like the boys (up to \ ~ 10 years). After the tenth year of life, however, the boys showed increasingly faster swimming speeds until the age of 17 as the girls.
Taken, these data suggest that girls are faster or at least not slower than the boys from the performance-enhancing effects of puberty. The whole study can be found under https://journals.plos.org/pllosone/article?id=10.1371/journal.pone.0225724