A Comprehensive Analysis of the Sex Difference with Increasing Age in 100-Mile Ultramarathon Performance

Abstract

Sex differences in endurance performance are often reported to range between 10% and 12%, however it remains unclear whether this disparity applies to ultramarathon events. Preliminary findings suggest that sex-based performance differences in ultramarathons are influenced by age, the participation of women, and course profile. Historically, men have had a large and consistent presence in ultramarathon events, but recent increases in participation from women and master's athletes highlight the need to examine how sex differences interact with advancing age. Among ultramarathon distances, the 100-mile event is regarded as the gold standard for competition. This study evaluated the impact of sex and age on 100-mile ultramarathon performance using data from 48,973 finishes between 2000 and 2023. Variables included age, sex, performance time, elevation metrics, temperature, and altitude. Linear regression models were used to assess predictors of performance. Age and sex accounted for less than 1% of finish time variance (R² ≤ 0.008); each year of age added 2.82–3.16 minutes, and women finished 28–30 minutes slower than men. Across four regression models, environmental predictors accounted for 24.8%–30.6% of variance, with elevation gain and loss emerging as the strongest contributors. Sex-based time differences ranged from 21 to 98 minutes across age groups. In the elite runners sample, sex differences ranged from 10.94%-28.47% compared to 0.67%-2.45% in the entire performance sample. Performance differences did not vary substantially across 10-year age groups. Findings suggest that broader female participation may help attenuate these disparities, particularly outside the top performance tiers.