In the Gothenburg University study, runners were asked to estimate their times before taking part in races. After they completed the race, their actual time was compared with the estimate.
"With the men we saw an average difference of six minutes, so they believe they are six minutes faster than they are," Mitesh Kataria from Gothenburg University told Sveriges Radio Gothenburg.
"For women who overestimated themselves we saw a difference of three minutes."
The researchers think the difference can to some degree be explained by men placing more emphasis on performing, with many male runners saying that their time is important motivation, while female runners focused more on health benefits.
Information from 5,000 runners in ten long-distance races was used in the study. And male overestimation may not be limited to running, according to researcher Kataria:
"The phenomenon of men tending to overestimate their ability may also apply away from races, for example in the labour market".