The performance gap between the world's best female and male runners has continued to narrow throughout the 21st century, according to a new study published in Scientific Reports. Tommaso Jucker of the University of Bristol's School of Biological Sciences analysed officially ratified World Athletics results from 2001 to 2025 and found that the average gap across 11 running events fell from 13.2 per cent in 2001 to 11.9 per cent in 2025. The finding challenges a widely held view that the difference between the sexes had stabilised at around 10 per cent from the 1980s onwards.
The dataset covers 11 disciplines from the indoor 60m to the marathon, taking in the 100m, 200m, 400m, 800m, 1500m, 3000m, 5km, 10km and half marathon along the way. Hurdles, steeplechase and the mile were excluded, as was the pandemic-affected 2020 season. For each event and year, Jucker kept only each athlete's fastest performance and then took the top 25 per sex, giving 13,094 performances by 3,611 athletes from 971 competitions. Repeating the analysis with the top 10 and top 50 athletes produced similar results, and the trends were modelled with linear mixed-effects models that allowed each event to follow its own trajectory.
Across the whole period, women's times averaged 12.6 per cent slower than men's. The gap was narrowest in the 60m, at 9.2 per cent, widened to a peak of 14.2 per cent at 10km, and then narrowed again in the half marathon and marathon. Men improved in every one of the 11 events, by an average of 2.2 seconds per kilometre, with their largest gains in the half marathon and marathon. Women, however, improved by an average of 4.5 seconds per kilometre, roughly twice as much, and on the roads their gains were striking: between 10.3 and 12.6 seconds per kilometre in the half marathon and marathon. In events from 800m upwards, the gap shrank by 1.9 percentage points, and the event with the largest gap shifted from the 10km to the 800m.
The obvious suspect is footwear, and the study acknowledges that advanced shoes may have contributed. But the improvements were broadly linear across the whole 25-year period, with no clear step change when carbon-plated shoes arrived on the roads around 2016 or when spike technology changed the track around 2021. That suggests shoes alone cannot explain the trend. The author points instead to the possibility that expanding opportunities for women in competitive running have played a part, and concludes that it is the faster improvement of women, rather than any stagnation among men, that is driving the convergence.
There are limits to what the data can show. The study describes historical trends among elite athletes and cannot establish causes, and its findings should not be read as applying to recreational runners. Physiological differences in aerobic capacity, muscle mass and hormones still underpin a substantial gap, and nothing in the data suggests it will close entirely. But for a sport that has seen women's world records fall repeatedly on the roads in recent seasons, the study offers a rigorous long-term context: the improvement is not a blip, and it has been under way for a quarter of a century.