Men are more likely than women to slow their pace in the marathon, according to a new study.
The study, led by Robert Deaner, associate professor of psychology at Grand Valley State University in the US, was based on 14 marathons that occurred in the US in 2011, and it included almost 92,000 performances.
On average, men ran the second half of the marathon 15.6 per cent slower than the first half, whereas women slowed by an average of 11.7 per cent.
Although the extent of slowing varied at different races, the sex difference in pacing occurred at all 14 marathons.
The sex difference was especially clear when considering runners who slowed by 30 per cent or more - men were about three times as likely as women to experience such dramatic slowing.
The researchers decided to conduct the study because they hypothesised that marathon pacing might reflect decision making, and previous studies show that men generally make riskier decisions in many other situations.
"Sports scientists have long been interested in pacing, but they have focused on elite athletes and haven't considered the role of decision making," said Deaner.
"We reasoned that decision making could be important for recreational runners - some have little knowledge about the demands of the marathon or their own capabilities, so it can be very easy to begin the early miles with an aggressive, unsustainable pace.
"We anticipated that men would be more likely to do this and, consequently, they'd be more likely to crash in the second half of the race," Deaner added.
While decision making could play a role, physiological factors might also be a primary factor explaining the greater slowing of men relative to women.
"Women typically use more fat and less carbohydrate during endurance exercise. This should make them less likely to 'bonk' or 'hit the wall' because they are less likely to have their muscles depleted of glycogen," said Sandra Hunter, a co-author and professor of exercise science at Marquette University in the US.
Outstanding endurance performances almost involve even pacing, so the new findings suggest that women are superior to men in their race pacing.
"Men are crashing more frequently and that certainly isn't desirable. But I think it's premature to conclude that women are superior pacers. This is because an evenly paced race does not automatically indicate a well-paced one," Deaner said.
"Someone might be too conservative given his or her training and ability. So this question won't be truly answered until a future study investigates runners' training and their goals, along with their pacing," he said.
The findings were published in the journal Medicine & Science in Sports & Exercise.
