Why men hit the marathon wall about twice as often as women — and what to do about it

# The headline finding A 2026 study of 873,334 Berlin Marathon finishers found men hit the wall nearly twice as often as women: 17.6% of men versus 9.7% of women, when the wall is defined as slowing 20% or more in the second half. A larger multi-race analysis using a stricter 25% slowdown definition reported 28% of men and 17% of women bonking.

# What "hitting the wall" looked like in the data The slowdown most often began around 29.5 kilometers (about mile 18) and lasted roughly 10–11 kilometers. Runners who hit the wall typically lost 31–33 minutes compared with their earlier pace — turning a projected 4:00 marathon into a 4:30 finish.

# Why biology doesn't tell the whole story Researchers highlighted physical differences — higher fat use, more slow-twitch fibers, and estrogen in women — that could help spare glycogen. But evidence for a consistent female advantage in fat burning is weak once body size is accounted for. Studies that adjusted for VO2max and racing experience reduced the sex gap but did not eliminate it, which means physiology matters, but it is not the whole explanation.

# Why pacing decisions explain most of the gap Multiple analyses point to the same behavioral cause: men more often set overly ambitious goal times and start faster relative to what they can sustain. Evidence includes:

• Large-scale reanalysis showing that starting the first 5K about 10% faster than average race pace can cost roughly 37 minutes across millions of finishers.

# Practical, research-backed pacing rules Follow a single, simple sequence to cut your risk of bonking:

1. 1Pick a realistic goal based on a recent race. Use a pace calculator only after entering a recent performance, not wishful thinking.
2. 2Set your opening 5K to goal marathon pace, or err on the safe side: 10–15 seconds per mile slower than goal pace.
3. 3Treat PR attempts like higher-risk efforts and offset that risk by being conservative early.

# The practical payoff A controlled opening pace preserves glycogen, reduces the chance of a large mid-late-race slowdown, and keeps projected finish times close to the plan. The data show most of the minutes lost to the wall are avoidable with a better-paced first 5K.

# Bottom line Men hit the wall more often mainly because they start too fast for their sustainable pace. Use a recent race to pick a realistic goal, run the first 5K at or slightly below goal pace, and reserve aggressive pacing for races where the extra risk is acceptable.