Are Women Actually More Durable Runners Than Men?

For decades, the conversation around sex differences in running has focused almost entirely on speed. Men run faster. That's the headline, and it tends to end the discussion there. But a study published in the Scandinavian Journal of Medicine and Science in Sports suggests that framing misses something significant: when it comes to holding pace over long distances, women don't just compete with men. They outperform them.

The numbers are striking. After three hours of continuous running, female runners slowed by approximately 1%. Men, over the same duration, slowed by up to 10%. That's not a rounding error. That's a physiological gap that has real implications for how we understand endurance, training, and what "durability" actually means in long-distance running.

What the Research Actually Found

The study tracked pace degradation in male and female runners across extended efforts, specifically looking at what happens to performance in the back half of long runs and races. The core finding: women maintain their pace far more consistently as fatigue accumulates.

This isn't just about finishing. It's about the quality of movement that persists deep into a run. While male runners showed significant pace drops in the final stretch of long efforts, female runners kept their splits remarkably stable. A 1% slowdown over three-plus hours is, by any athletic standard, exceptional pacing discipline. Except it wasn't pacing discipline. It was physiology.

The researchers point to a specific muscular factor as a key driver: knee extensor function. The quadriceps muscles, which are central to maintaining running economy and stride mechanics, held up significantly better in female runners during prolonged efforts. When your knee extensors fatigue, your form degrades, your ground contact time increases, and your pace drops. Women, the data suggests, are simply more resistant to that breakdown.

The Muscular Durability Advantage

Why would women's knee extensors hold up better? Several mechanisms are under investigation, but the evidence points toward differences in muscle fiber composition, fatigue resistance, and recovery dynamics within the muscle itself.

Women tend to have a higher proportion of slow-twitch (Type I) muscle fibers relative to their total muscle mass. These fibers are more fatigue-resistant and more efficient at sustained, aerobic output. They don't produce peak power the way fast-twitch fibers do, but they're built for the long game. In a marathon or ultra context, that's not a limitation. It's an asset.

There's also evidence that female muscle tissue responds differently to oxidative stress. The cellular damage that accumulates over the course of a long run appears to affect male muscle fibers more acutely, contributing to the steeper performance drop observed in the data. This isn't about pain tolerance or mental toughness. It's about what's happening at the fiber level, and women appear to have a structural edge when the run goes long.

This muscular durability also connects to why women tend to perform better in ultramarathon distances relative to men than they do in shorter races. The longer the event, the more this advantage compounds. At 50 miles or 100 miles, the pace gap between elite men and women narrows considerably compared to a 5K or 10K.

Metabolic Efficiency Over Distance

The muscular story is compelling, but it's not the whole picture. Women also show a measurable advantage in metabolic stability during prolonged running efforts.

Research consistently shows that women rely more heavily on fat oxidation as a fuel source during aerobic exercise, particularly at moderate intensities. Fat is a near-unlimited energy source in the context of distance running. Carbohydrate stores are finite, typically enough to fuel roughly 90 minutes to two hours of hard running before depletion starts affecting pace. The ability to access fat more efficiently, especially in the three-plus-hour range, means women are less dependent on exogenous carbohydrates to maintain output.

This metabolic flexibility also contributes to a more stable energy state late in long runs. Men tend to hit harder glycogen depletion curves at similar effort levels, which amplifies the pace degradation the study observed. Women's calorie-burning patterns stay more consistent, which supports more consistent movement.

Getting your nutrition right plays a role here too. What you consume before and during long runs affects how long your metabolism stays efficient. Beetroot juice lowers blood pressure and supports vascular efficiency, which may complement the metabolic picture for long-distance runners of any sex. The interaction between nutrition and endurance performance is increasingly specific, and the research keeps refining our understanding of it.

Rethinking What "Better" Means in Running

None of this means women will beat men head-to-head at the elite level of standard marathon distances anytime soon. Testosterone-driven differences in VO2 max, hemoglobin levels, and absolute muscle mass still produce a meaningful performance gap in time-based competition. That's not the point.

The point is that durability, which is the ability to hold form, pace, and metabolic efficiency deep into a long effort, is a distinct quality from raw speed. And on that measure, the data increasingly shows that women hold a real, physiological edge. That reframes a lot of conventional training wisdom and challenges some of the assumptions coaches and athletes have long carried into endurance programming.

It also raises an interesting question about how training for durability has been designed. Most conventional marathon training plans have been built around data from male athletes. If female physiology responds differently to fatigue, recovers differently from volume, and holds up better at the back end of long runs, then programs designed specifically for female runners should look different. Not easier. Different.

The psychological dimension matters too. Running for a cause has been shown to improve late-race performance, and that mental resilience likely interacts with the physiological factors at play here. Durability isn't purely physical. But understanding the physical baseline is the foundation.

How Any Runner Can Train for Late-Race Durability

Whether you're male or female, the mechanisms behind women's durability advantage point directly to trainable qualities. Here's what the research suggests any runner can do to improve their own performance in the final third of a long run.

Build muscular endurance in the quads specifically. Knee extensor fatigue is a central driver of pace degradation. Single-leg squats, step-downs, and eccentric quad work done consistently over a training block will improve the resilience of exactly the muscles this research identified. Don't skip strength training because you're a runner. Strength is increasingly recognized as a top health and performance priority, and the running data supports that conclusion.
Train your fat oxidation system. This means including some long runs at genuinely easy aerobic paces, where you're burning primarily fat rather than carbohydrates. Fasted easy morning runs, done carefully and not at high intensity, can improve metabolic flexibility over time. The goal is to extend the range at which your body burns fat efficiently before it needs to lean on glycogen.
Practice running on tired legs. Back-to-back long run weekends, or tempo efforts scheduled after a moderate long run, teach your body to maintain form under accumulated fatigue. This is a deliberate stress that forces neuromuscular adaptations. It's uncomfortable and should be used sparingly, but it directly trains the quality that separates durable runners from those who fade.
Introduce varied terrain. Trail running builds the stabilizing muscles and proprioceptive awareness that road running ignores. Those qualities translate directly into better form retention late in a run, when fatigue starts compromising movement patterns.
Prioritize late-run fueling as a skill. Practice taking in carbohydrates during your long runs at the three-hour mark and beyond. Your gut's ability to absorb nutrition while running hard is trainable. Building that capacity reduces the metabolic cliff that accelerates pace degradation.

What This Means for How You Race

If you're a woman reading this, the research validates something many experienced female runners have known intuitively: you may be better built for the long run than the conventional performance tables suggest. That's worth factoring into how you pace long races. Starting conservatively and trusting that your durability advantage compounds over time isn't just strategic. It's physiologically sound.

If you're a man, this data isn't discouraging. It's useful. The 10% pace drop observed in male runners isn't inevitable. It's a ceiling that training, nutrition, and smart pacing can push back significantly. Understanding where the vulnerability is makes it easier to address directly.

Endurance running has always rewarded those who understand their own physiology rather than chasing generic benchmarks. This research adds a sharper lens to that process. Women aren't slower runners who happen to finish. They're durable runners whose specific strengths show up most clearly when the race gets long and the body gets tested.

That's a different conversation than the one running has been having. It's also a more accurate one.