Why men “hit the wall” 2 x more often than women

Most runners blame hitting the wall on running out of fuel.

New data from 873,334 Berlin Marathon finishers points at something you control much earlier in the race.

Men hit the wall at nearly twice the rate of women, and the gap does not disappear when you account for how fast they run or how many marathons they have finished.

The better explanation is the pace runners choose in the first 5K, and you make that decision before the gun goes off.

So, in this article you’re going to learn the research-backed practical advice on…

• How often runners in your finish-time range actually hit the wall, and what it costs in minutes
• Why men blow up more often than women, and why the answer is mostly a decision rather than biology
• The one situation where your risk of hitting the wall jumps by more than half
• Exactly how many minutes a fast first 5K costs you, and how to set your opening pace so it never happens

How Often Do Marathon Runners Actually Hit the Wall?

Somewhere between 1 in 6 and 1 in 3 marathon runners hit the wall, depending on how strictly you define it.

The Berlin study defined the wall as running the second half of the marathon at least 20% slower than the first half.

A 2026 analysis of 873,334 Berlin Marathon finishers found that 17.6% of men and 9.7% of women hit the wall, defined as slowing 20% or more in the second half.

Across all runners in the study, men slowed by an average of 10.7% in the second half and women slowed by 8.3%.

A runner who goes through halfway in 2 hours and then slows 20% finishes in 4 hours 24 minutes.

A second, larger study used a stricter definition and found the same pattern.

Researchers analyzing 4.2 million race records from 270 marathons counted a runner as hitting the wall only if their pace dropped by 25% or more for at least 5 kilometers after the 20K mark.

By that definition, 28% of men and 17% of women hit the wall.

The slowdown usually started around 29.5 kilometers, which is mile 18, and lasted for about 10.7 kilometers in men and 9.6 kilometers in women.

The average runner who hit the wall lost 31 to 33 minutes compared to what their earlier pace would have produced.

That means the wall turns a 4:00 marathon into a 4:30 marathon, and the slowdown lasts for about 6 miles.

Why Do Men Hit the Wall More Often Than Women?

Researchers have offered two explanations for the sex gap, and the evidence is much stronger for one of them.

Is the difference physiology?

The Berlin researchers point to three physical differences: women burn a higher share of fat at marathon effort, carry a greater proportion of slow-twitch muscle fibers, and have higher estrogen levels.

All three would help women spare glycogen, the stored form of carbohydrate in your muscles and liver, and delay the point where it runs out.

The fat-burning claim is the weakest of the three.

A 2026 review of 36 studies covering 8,990 people found that women burned 0.06 grams of fat per minute less than men at their peak fat-burning intensity, and the difference disappeared once body size was accounted for.

The authors concluded that the assumption that women always burn more fat than men during exercise is not supported.

A fairer objection is that a 4-hour marathon is a harder relative effort for a woman than for a man, so you would expect her to slow more, and she slows less.

Researchers have tested that objection directly.

A 2015 study of 91,929 finishers from 14 US marathons adjusted every woman’s time by 12% to account for men’s higher VO2max and also controlled for racing experience.

Before any adjustment, men slowed by 15.6% in the second half and women slowed by 11.7%.

Both adjustments shrank the gap, and neither one removed it.

That means physiology explains part of the gap and leaves a large part of it unexplained.

Is the difference how men set their goal pace?

The most direct evidence comes from a study that compared what runners said they would run with what they actually ran.

Researchers at the 2013 Houston Marathon collected predicted finish times from 4,428 runners at registration and matched them to results.

Men finished 9.0% behind the time they predicted, and women finished 7.6% behind theirs.

The runners who overestimated themselves the most were the same runners who slowed the most in the second half.

A goal time that is too ambitious turns into an opening pace that is too fast.

A 2025 reanalysis of the 2015 data supports the same reading.

The reanalysis found that the sex difference in pacing only shows up among younger runners and runners with longer finish times, and the authors argued the pattern looks social rather than biological.

The part of the gap you control is your opening pace, and you can test whether your goal time is honest weeks before race day.

Does Being Faster Protect You From the Wall?

Faster runners hit the wall far less often, but the sex gap is present at every finish time.

The Berlin study split runners into five groups by finish time, and the gap between men and women was largest in relative terms at the fast end.

Among runners finishing under 3 hours, 1.4% of men hit the wall compared to 0.2% of women, which is a sixfold difference in the odds.

Among runners finishing slower than 4:30, 41.6% of men hit the wall compared to 17.7% of women.

For most runners, the second number is the one that matters.

One more finding from the 4.2 million record study explains when the risk climbs.

In the 3 years leading up to a runner’s personal best, 36% of race records showed the runner hitting the wall, compared to 23% in the years outside that window.

Those are the years a runner is chasing a personal best, and the study authors attribute the extra risk to the more aggressive pace required to chase one.

That means a PR attempt is the race where you need the most discipline in the first 5K, because it is the race where you are most tempted to bank time.

How Much Time Does Starting Too Fast Cost You?

Banking time in the first few miles feels free, and researchers have put a price on it.

The study compared each runner’s first 5K pace to the average pace they held for the whole race.

An analysis of 1.7 million marathon finishers found that runners who ran the first 5K 10% faster than their average race pace finished about 37 minutes slower than runners who started at their average pace.

Runners who started 20% faster than their average pace hit the wall 44% of the time.

For a 4:00 marathon, average pace is 9:09 per mile (5:41 per km).

Starting 10% faster is 8:19 per mile (5:10 per km), which is close to the pace most 4:00 marathoners run their tempo runs at.

Starting 20% faster is 7:38 per mile (4:44 per km), which is a pace most 4:00 marathoners cannot hold for a 10K.

Running 8:19 pace instead of 9:09 for the first 5K puts you about 2 and a half minutes ahead of schedule at the 5K mark.

That means you trade 2 and a half minutes banked early for roughly 37 minutes lost late.

The same study counted how many runners of each sex finished slower than they started.

Among men, 65% finished slower than they started, compared to 47% of women.

Among women, 26% finished faster than they started, compared to 16% of men.

The runners with the best finish times in the entire dataset ran the first 5K at their average race pace, or within a few seconds of it.

How Should You Pace the First 5K to Avoid the Wall?

The fix has two parts: set a goal pace your fitness supports, and refuse to run the first 5K faster than it.

How do you know if your goal time is honest?

The goal itself is your first pacing decision, because the runners in Houston who overestimated their goal were the runners who slowed the most.

Use a half marathon or 10K from the last 8 weeks and run it through a pace calculator.

If the predicted marathon time is slower than the goal you had in mind, use the predicted time.

What pace should you run the first 5K?

Goal pace is the ceiling for your opening miles.

I have my athletes run the first 5K 10 to 15 seconds per mile slower than goal pace, which is the same principle behind the 10-10-10 method I use for the full race.

For a 4:00 goal, that means the first 5K is run at 9:19 to 9:24 per mile (5:47 to 5:50 per km).

Check your watch at the 5K mark, and if you are ahead of goal pace, ease off for the next mile until you are back on it.

How should the first 3 miles feel?

Goal marathon pace should feel too easy for the first 3 miles, easy enough that you could speak in full sentences.

If you are breathing hard at mile 2, you are running closer to tempo pace than marathon pace, and the slowdown arrives around mile 18.

Can fueling make up for a fast start?

Taking in carbohydrate during the race still matters, because your glycogen stores hold about 90 to 120 minutes of running at marathon effort.

A fast start burns through those stores earlier, and gels replace only a fraction of what you burn each hour, so fueling cannot cover a pacing mistake.

If the full plan is more than you will manage on race morning, do one thing: do not let your first mile be faster than goal pace.

Decide Your First 5K Before the Gun Goes Off

Men hit the wall at nearly twice the rate of women, and the best evidence says the difference comes mostly from the pace they choose in the first 5K.

Starting 10% too fast costs the average runner about 37 minutes, and the wall itself costs 31 to 33 minutes when it arrives.

Start with your goal: run a recent half marathon or 10K through a pace calculator and accept the number it gives you.

Then run the first 5K at that pace or 10 to 15 seconds per mile slower, check the split, and ease off if you are ahead.

If you are chasing a personal best, this is the race where that discipline matters most.

Finding	What the data showed	What it means for your race
Men hit the wall more often	17.6% of men vs 9.7% of women slowed 20% or more in the second half across 873,334 Berlin finishers	Assume a fast start ends in the wall and plan the first 5K to prevent it
Overconfident goals predict slowing	Men finished 9.0% behind their predicted time, women 7.6%, and the biggest overestimators slowed the most	Set your goal from a recent race through a pace calculator
Fast starts have a fixed price	A first 5K run 10% faster than average pace cost about 37 minutes across 1.7 million finishers	Run the first 5K at goal pace or 10 to 15 seconds per mile slower
PR attempts raise the risk	36% of runners hit the wall in the 3 years before a personal best vs 23% in other years	Hold your opening pace hardest in the race you care about most