Sex-based differences in running performance among children aged 7-9 years in New South Wales track competition.

BACKGROUND: Recent research has shown that prepubertal males outperform females in running competitions; however, prior studies have focused on distances of 100-1600 m and most have relied on U.S.-based data. This study evaluated sex-based differences in running performance among under-8, under-9, and under-10 athletes in 70 m, 100 m, 200 m, and 400 m races at the 2024 Little Athletics New South Wales (NSW) Regional Track & Field Championships in Australia. METHODS: Official race times for all competitors (n = 1442 males; 1405 females) from all seven NSW regional meets were analyzed. Performance was compared by sex for both preliminary and final times using two-way ANOVA. Additional analyses examined time gaps between successive finishers within each sex and time differences between male and female athletes placing in the same ordinal position, using ANOVA on ranks. RESULTS: Males ran significantly faster than females across all events and age groups (P < 0.05), with an average advantage of 4.88 ± 0.57 % and medium to large effect sizes (Hedges' g = 0.451-0.878). In contrast, within-sex time gaps between successive finishers did not differ significantly (males: 1.63 ± 0.12 %; females: 1.71 ± 0.17 %). CONCLUSIONS: These findings confirm previously reported male performance advantages in prepubertal children and extend the evidence to a shorter sprint distance (70 m) and to Australian data. Notably, between-sex performance differences were more than twice as large as the variability within sex among comparably placed finishers. These results may help inform research and practice on youth sport talent identification and development.