- New research reveals men hit the wall in the marathon nearly twice as often as women, and the primary cause does not come down to fitness level.
- Experts recommend strategies for maintaining pace through the end of the race.
Every marathoner knows one of the biggest risks that comes with running 26.2 miles is hitting the wall or “bonking” late in the race. Fueling well and training with long runs will carry you through the distance. But one of the biggest factors that can prevent the dreaded bonk and help you reach your goal is learning how to pace well.
And new research says men should pay particular attention.
The study, published in Scientific Reports, examined the 5K splits, halfway splits, and net finish times of more than 873,000 runners in the Berlin Marathon over the course of the past 27 years. From the data, researchers found the prevalence of hitting the wall was nearly double in men, compared with women. In this case, researchers defined “hitting the wall” as slowing down by 20 percent or more in the second half of the marathon compared with the first half.
The findings showed hitting the wall was prevalent in nearly 18 percent of men, compared with just under 10 percent of women. The risk disparity widened among faster runners: In the sub-three-hour category, male runners were approximately six times more likely to slow down than their female counterparts.
“What surprised us most is that experience and fitness did not protect the men [from being less likely to hit the wall],” says Aldo Seffrin, PhD, researcher at the Federal University of São Paulo in Brazil and the study’s lead author. “How you distribute your effort matters as much as how fit you are, and pacing is something anyone can train.”
“The wall is one of the most talked-about experiences in the marathon, but it is rarely quantified at scale, so we wanted to move it from anecdote to data,” Seffrin adds.
He refers to two older studies that identified similar trends when comparing men’s performance to women’s in U.S. marathons. The study in Berlin gave researchers a larger dataset to work with, examining a record-friendly course, and ultimately validated the hypothesis that men, regardless of performance level, are more prone to aggressive pacing and deceleration.
It should be noted, though, that the study did not account for weather conditions over the course of 27 years, and excluded runners who did not finish.
Why Are Men More Likely to Slow Down?
As for why men are more prone to hitting the wall on marathon race day, the researchers suggest that male runners may be prone to adopting high-risk strategies, like running closer to their physiological ceiling, potentially because of the pressure to compete and the stress of race day affecting their decision-making process.
Past behavioral research suggests that this may be due to men, on average, more often overestimating their competitive ability and tolerating higher risk in competitive contexts than women, the study notes, which could manifest as starting out too fast and lacking pacing discipline.
The researchers also say women may be less likely to hit the wall due to their ability to tap into fat for fuel at an earlier and more efficient rate compared with men, and women have a greater relative proportion of slow-twitch muscle fibers, which are more fatigue resistant and can carry you through endurance efforts. Both of these elements together allow women to spare more glycogen, delaying the wall.
As a triathlete, coach, and someone who has also bonked, Seffrin is invested in the research and plans to continue it further. This likely means testing for the same gap on other courses, among runners who DNF, and measuring behavioral and physiological pieces of evidence like metabolism (to further examine the differences in glycogen stores), he explains. “It is part of a larger series we are running on the Berlin Marathon, so there is more to come,” he adds.
How to Avoid Hitting the Wall on Race Day
So, how do these findings affect your training, if at all? The study suggests male distance runners, particularly those aiming for ambitious time goals, like breaking three hours, would benefit from pacing strategies that mimic conservative starts and even or negative splits.
“The men most likely to fall apart were often the fitter, faster ones, which points to pace, judgment, and behavior rather than a lack of training,” says Seffrin. “Fitness gets you to the start line fast, but pacing is what gets you to the finish line strong.”
Below are some tips on pacing your marathon well so you don’t slow down in the second half.
Try the 10/10/10 Method
The 10/10/10 marathon pacing strategy is simple:
- Run the first 10 miles at a pace that’s slower than your goal marathon pace.
- Run the second 10-mile stretch right at goal marathon pace.
- Run the final 10K faster than goal pace, picking off runners one by one.
This method is tried and true to avoid going out too fast from the starting line, and allows you to shoot for negative splits.
Hack the Final Miles
Research suggests that professional runners use focused attention rather than distraction to get through difficult miles, especially later in a race, Runner’s World previously reported.
To do that, focus on how you’re running—concentrating on breathing, form, and narrowing your visual field—rather than thinking about your why or your broader goals. (Keep in mind this works better later in the race, not from the start!)
You can also try gamifying the final miles of the race by breaking the final 6.2 into smaller chunks, counting down each mile instead of up, or counting how many competitors you can pass before the finish line.
These tricks help you maintain motivation in the moment and run stronger in those final miles.
Use Effort to Maintain Even Splits
Maintaining even splits doesn’t have to be difficult. Dave Masterson, a 61-year-old pace group leader who’s run more than 70 marathons, says he checks elapsed time at each mile marker (rather than average pace) and carries a printed chart with target elapsed times to make sure he’s on track. He also stays in tune with his effort level.
“In large marathons, it can take several miles just to settle into your goal pace as you navigate starting line crowds,” Masterson previously told Runner’s World. However, even if you wind up 45 seconds off goal pace after the first three miles because of a congested start, making up just five seconds per mile over the next nine miles is well within your manageable effort range, he says. (As long as you set a smart pace goal!) And that will get you right back on pace before the halfway mark.
Make Sure You Fuel Well
So many runners bonk on race day because they lack enough fuel to keep performing. Eating enough calories and carbs in the days leading up to and on race day ensures you can carry out your goal pace so you’re not crashing by the end. “Fueling matters. Since the wall is ultimately about running low on carbohydrates, a solid carbohydrate strategy before and during the race helps,” Seffrin says.
Experts generally recommend taking in 30 to 120 grams of carbs per hour throughout the race, depending on what your stomach can handle and what you practiced in training, washed down with about eight ounces of water.
Topping off your glycogen stores should also start about three days before the marathon. Aim for 4 grams of carbs per pound of bodyweight per day. And make sure you fill up on breakfast before you hit the start, going for at least 0.5 grams of carbs per pound of bodyweight about two to four hours before the race.
Kristine Kearns, a writer and avid runner, joined Runner’s World and Bicycling in July 2024. She previously coached high school girls cross country and currently competes in seasonal races, with more than six years of distance training and an affinity for weightlifting. You can find her wearing purple, baking cupcakes, and visiting her local farmers market.
