An International Program Is Born to Protect Women's Health in Ultra Trail Running

While the UTMB Mont-Blanc was experiencing one of its most memorable weeks thanks to women's prominence at the finish line, news was developing that could change how we understand—and care for—female performance in the mountains: an international program dedicated exclusively to researching and protecting the health of women competing in ultra-distance races is being born. If you run trail, if you coach female runners, or if you simply care that sports science stops treating female athletes like "small men," this concerns you directly.

The Context

For decades, endurance sports science was built almost entirely on data from male athletes. The nutrition, hydration, strength training, and injury management protocols that are applied today to ultra trail runners were, in their vast majority, extrapolated from studies conducted with men. The problem is not minor: the female body has physiological particularities—menstrual cycle, body composition, thermal response, bone density—that interact differently with the stress of running 100 miles through mountains.

This new international program seeks to close that gap comprehensively, not only through isolated studies but with a sustained research agenda over time. Its emergence is no coincidence: it arrives in a week where the UTMB—the most high-profile and prestigious ultra trail race on the planet—had women dominating headlines, records, and narratives. Sports visibility is finally driving scientific investment. It's a belated but necessary recognition: if women are leading the competition, the science supporting them must be up to the task.

What Science Says

The available evidence had already been setting the stage. A recent review of sex differences in endurance races (Besson et al., Sports Medicine, 2022) confirms that men and women differ not only in performance times, but in key variables like energy substrate utilization, thermoregulation, and neuromuscular fatigue during prolonged efforts. This means that race strategies designed "generically" may be suboptimal for the female body.

Along the same lines, a study on pacing in half-marathons and marathons (Nikolaidis, Ćuk and Knechtle, 2019) showed that women tend to manage their pace more evenly than men, who typically start faster and pay the price in the second half. This strategic difference—possibly linked to physiological factors and decision-making—is exactly the kind of finding that a dedicated program could deepen in the specific context of mountain running, where elevation and duration multiply the variables.

There's also an important gap in bone health. Research on bone stress injuries (Warden, Davis and Fredericson, 2014; George et al., 2024) is fundamental for ultra trail, a discipline where the volume of accumulated impact is enormous, and where women-specific hormonal factors—including menstrual health—directly influence the risk of stress fractures. Without specific data on women in the mountains, prevention and return-to-activity protocols were, at best, an approximation.

Finally, work on personalized nutrition in elite performance (Sutehall and Pitsiladis, 2025) reinforces the central idea behind this entire movement: the future of endurance sports is not in universal protocols, but in individualized strategies that consider each athlete's sex, biology, and context.

What It Means for You

You don't need to compete at the UTMB to benefit from this paradigm shift. If you're a trail or ultra runner, here's what you can start applying today:

• Stop copying male protocols without adjusting them. Your carbohydrate management, hydration, and pacing in the mountains deserve a strategy of your own, not a scaled-down version of a male teammate's.
• Pay attention to your menstrual cycle as a training variable. It's not a secondary detail: it can influence your heat tolerance, your recovery, and your risk of bone injury.
• Prioritize strength work. The evidence on running economy and fatigue in long efforts (Zanini et al., 2025) is clear: strengthening yourself reduces technical deterioration in the final hours of an ultra, something critical for any female runner.
• Demand (and seek) specific information. This program is a signal that the scientific community is listening. As a runner, informing yourself with sources that speak to you—not a generic version of an athlete—is part of training smart.

The science of female ultra trail running is finally catching up with what athletes have already been demonstrating in the mountains. Here's hoping it's the beginning of many more steps in that direction.

References

• Besson T, Macchi R, Rossi J. "Sex Differences in Endurance Running." Sports Medicine, 2022. https://pubmed.ncbi.nlm.nih.gov/35122632/
• Nikolaidis PT, Ćuk I, Knechtle B. "Pacing of Women and Men in Half-Marathon and Marathon Races." Medicina (Kaunas), 2019. https://pubmed.ncbi.nlm.nih.gov/30646638/
• Warden SJ, Davis IS, Fredericson M. "Management and prevention of bone stress injuries in long-distance runners." J Orthop Sports Phys Ther, 2