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Sex differences in human running performance: smaller gaps at shorter distances?

Human, but not canine or equine running performance, is significantly stratified by sex. The degree of stratification has obvious implications for classification and regulation in athletics. However, whether the widely cited sex difference of 10-12% applies equally to sprint and endurance running events is unknown. Here, different determining factors for sprint (ground force/body mass) vs. endurance performance (energy supply & demand) and existing trends, led us to hypothesize that sex performance differences for sprint running would increase with distance and be relatively small. We quantified sex performance differences using: 1) the race times of the world's fastest males and females (n=40 each) over a 15-year period (2003-2018) at nine standard racing distances (60-10,000m), and 2) the 10-meter segment times of male (n=14) and female (n=12) athletes in World Championship 100-meter finals. Between-sex performance time differences increased with sprint event distance [60m-8.6%, 100m-9.6%, 200m-11.0%, 400m-11.7%] and were smaller than the relatively-constant mean (12.4±0.3%) observed across the five longer events from 800-10,000 meters. Between-sex time differences for the 10-meter segments within the 100-meter dash event, increased throughout spanning 5.6% to 14.2% from the first to last segment. We conclude that sex differences in sprint running performance increase with race and running distance.