On really long hikes — the Appalachian Trail and beyond — women may do better than men at setting speed records.

At some point, the female body has an advantage:

Robert Deaner of Grand Valley State University in Allendale, Mich., has spent the past 10 years studying the psychological differences in distance running between the sexes...  Men “begin at a pace that could lead to a superb performance, given their own talent and training, but one that also increases their chance of crashing or hitting the wall. The longer the race, the more crucial it is to be conservative with pacing, since fatigue in longer races reflects slowly cumulating processes, such as glycogen depletion and tissue damage.” Although data on longer distances is lacking, Deaner acknowledges, “since males generally have trouble making conservative decisions, they might be less likely to perform well in an ultrarun or hike.”...

“Women appear to be better suited for walking long distances because it doesn’t seem to take the same physical toll on their bodies,” [said record-setting hiker Heather Anderson]. “The women I see at the end of a long-distance hike look fit and badass, but the guys look emaciated.... I believe that endurance is most likely genderless... As a species we evolved by traveling long distances and carrying what we needed. It’s a human trait.”

Samuel Cheuvront, a research physiologist for the United States Army Research Institute of Environmental Medicine, agreed. “I can’t think of any reason why men would have an advantage over women at these lengths,” he said. “At distances over 2,000 miles, you are negating the benefit that males have due to increased muscle mass and aerobic capacity.”...