Marathon Study from Zurich: Men Experience "Hitting the Wall" Roughly Twice as Often as Women

The research team around the Swiss Beat Knechtle defined "Hitting the Wall" as a reduction in average pace of at least 20 percent in the second half of the marathon compared with the first half. The term refers to a sudden and dramatic drop in performance that occurs when the body has exhausted its short-term energy reserves. Glycogen, the storage form of glucose, serves as a short-term energy reserve and is used up relatively quickly during intense exertion.

What Is "Hitting the Wall"?

The results are clear: in men, the phenomenon known as "Hitting the Wall" is likely about twice as common as in women, according to the study published in "Scientific Reports". Men experienced the "Hitting the Wall" phenomenon nearly twice as often, with just under 18 percent of them affected. Among women, the figure was below 10 percent. On average, men also reached the finish line faster, in 4 hours and 2 minutes compared with 4 hours and 29 minutes for women, but they distributed their energy less carefully.

The difference is particularly pronounced among fast runners. Among male runners who completed the marathon in under three hours, the rate of performance collapse was six times higher than among women (1.42 versus 0.23 percent). Overall, 52 percent of women showed no clear decline in performance over the course of the marathon – compared with just over a third (36 percent) of men.

Fast Men Are Especially Frequently Affected

As a possible explanation, the team suggests that the female body uses up its glycogen reserves more sparingly while running. Sex-specific differences in metabolism and in the proportion of certain muscle fiber types could effectively delay the depletion of glycogen stores that triggers the "Hitting the Wall" phenomenon. According to the findings, women have more muscle fibers geared toward endurance rather than sprinting and may be able to use their glycogen stores more efficiently.

Behavioral research also indicates that men tend to overestimate themselves and be more willing to take risks. However, these are only speculations by the research team; the current study did not collect data on this point. Co-author Aldo Seffrin said it was interesting and surprising that the sudden performance collapse was not a beginner's problem for men, but was in fact particularly pronounced among very fast runners: „Dass sie fitter und erfahrener waren, hat die Männer nicht geschützt."

Possible Causes: Metabolism, Muscle Fibers, and Risk-Taking

Thomas Rosemann, director of the Institute of Primary Care Medicine, who was also involved in the study, explained that various psychological and physiological factors could be responsible for the observed effect. It is also possible that men often start the marathon far too quickly and overestimate their energy reserves – also because of their higher testosterone levels compared with women.

The researchers recommend that men start the race more slowly and accelerate only later. This may reduce the risk of "Hitting the Wall". Seffrin stressed that many men would benefit from starting more conservatively. Women run more evenly and maintain their pace even in the second half.

Researchers' Recommendation: Start Slower

For researcher Knechtle, the findings have direct practical use beyond science: he himself is an enthusiastic and regular marathon runner. The authors note that the fact that men more frequently slow down over the course of a longer run had already been established by earlier research. However, it had not previously been demonstrated whether the phenomenon could be observed in large cohorts, that is, on a bigger scale. From an evolutionary standpoint, the difference makes sense to the researchers, since in the Stone Age men as hunters presumably often had to sprint quickly, while for women endurance would have been more important than high speed.

Alongside the study findings, one of Switzerland's largest endurance events is currently taking place in Thun with Ironman Switzerland, in which around 2,300 athletes are competing. The race consists of 3.8 km of swimming, 180 km of cycling, and a full marathon. The study was published by the University of Zurich, and the article appeared via APA on 5 July 2026.