Women's Ultramarathon Challenge: The Physiological Advantages of Women in Ultra-Distance Events

Introduction

In 2019, Courtney Dauwalter finished the Western States 100-mile ultramarathon in a course-record time, placing second overall among all runners, regardless of gender. Her story is no coincidence—in major ultramarathons around the world, female runners are steadily closing the gap with men, and in some ultra-long-distance events, they are even surpassing them.

This is not luck; it is physiology.

A Reversal of Traditional Beliefs

In standard marathons (42.195 km), elite male runners are about 8–10% faster than women—a gap that is even larger in shorter distances (about 10–11% in the 100 m). But as distance increases, the gap begins to narrow:

Why does the gap shrink as distance grows?

Women’s Physiological Advantages in Ultra-Distance Events

1. Greater Fat Oxidation Capacity

Women’s bodies naturally use a higher proportion of fat as fuel during aerobic exercise compared to men. Research shows that at the same exercise intensity, women’s fat oxidation rates are about 25–30% higher than men’s. Fat is the key energy source in ultramarathons—carbohydrate stores are limited (about 1,800–2,000 kcal), while body fat reserves (even in lean runners) typically exceed 40,000 kcal.

2. The Metabolic Shield of Estrogen

Estrogen provides protective effects during prolonged exercise:

• Reduces muscle breakdown during exercise (lower protein oxidation rates)
• Antioxidant properties that delay oxidative stress damage from exercise fatigue
• Helps stabilize blood sugar, reducing the risk of hypoglycemic crashes

3. More Stable Pacing Strategies

Research shows that women tend to pace better than men in ultra-long-distance events. Male runners are more likely to start too fast in the first half and fade in the second half (Positive Split), while women tend toward more consistent pacing distribution (Negative Split or Even Split). This is crucial in ultramarathons—losing control of pacing is the primary cause of most DNFs (Did Not Finish).

4. Heat Tolerance and Hydration Strategies

Some studies show that women perceive high temperatures more intensely, but their actual core body temperature rise rate in hot ultramarathon conditions is not slower than men’s. Female runners also tend to be more cautious and systematic with hydration and fueling.

5. Mental Toughness

This is harder to quantify, but a widely observed phenomenon in the ultramarathon community is that female runners often demonstrate a stronger will to keep going under extreme fatigue and discomfort. This may be related to women’s long-term daily experience of continuing to function under uncomfortable conditions (such as working through menstrual pain, sleep deprivation from postpartum breastfeeding, etc.).

The Rise of Women’s Ultramarathons in Taiwan

In recent years, more and more women in Taiwan have taken on ultramarathon and trail running challenges:

• The proportion of female participants in Taiwan’s 100K ultramarathon events continues to rise
• Trail events such as TVTC (Taiwan Trail Running Circuit) are attracting more female finishers
• In international events, the visibility of Taiwanese female runners in Asian ultramarathons has increased significantly

Special Considerations for Women’s Ultramarathon Training

• Menstrual cycle management: Ultramarathon events typically last 24 hours to several days; if they coincide with menstruation, adequate sanitary supplies and carrying plans are essential
• Mileage increase and bone health: Ultramarathon training volume is high, so iron, calcium, and vitamin D supplementation must keep pace
• Energy strategy: Nutrition plans in ultramarathons need to include sufficient carbohydrates and solid food to avoid LEA (Low Energy Availability)
• Safe training: Ultramarathon training often takes place on mountain roads or remote areas; training with a partner and informing others of your whereabouts is especially important

Practical Advice

1. Start with a 50K: Taiwan has several 50K ultramarathon events that are ideal entry points, with well-stocked aid stations and runner-friendly courses
2. Train fat oxidation capacity: Periodically incorporate low-intensity, long-duration aerobic training (heart rate at 60–70% of max HR) to improve fat metabolism efficiency
3. Join women’s ultramarathon communities: Taiwan has dedicated women’s trail/ultramarathon groups, where experienced runners’ gear advice and race strategies are the most direct resources
4. Prioritize your fueling plan: Forgetting to fuel in an ultramarathon is more fatal than being slow; practice your nutrition plan at race pace so eating becomes an automatic habit
5. Accept the possibility of a DNF: The DNF rate in ultramarathons is far higher than in regular marathons, but a DNF is a wise decision, not a failure—finishing safely is what allows you to enter the next race

Conclusion

The ultramarathon is one of the race formats where distance most effectively erases gender differences, and women’s physiological traits are beginning to reveal unique advantages in the most extreme distance challenges. This is not just encouragement for female athletes—it is a profound insight into human exercise physiology: run long enough, and the meaning of the finish line matters far more than the differences at the starting line.

Related Reading

• The Rise of Female Ultramarathon Runners: Women’s Physiological Advantages in Long-Distance Running
• Physiological Characteristics of Female Ultramarathon Runners: Research on the Gap Between Men and Women Narrowing with Distance
• Physiological Profile Analysis of Ultramarathon Runners: Metabolic Phenotype Study of 100-Mile Finishers
• The Real Differences Between Female and Male Endurance Physiology: From Substrate Utilization to Body Temperature, What the Evidence Can and Cannot Say