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.” In contrast, all three times a woman has attempted to set the overall supported or unsupported record on the Appalachian Trail or Pacific Crest Trail, she has been successful.

Does One Sex Have Edge?

On Aug. 1, 17 days after Jurek reached Katahdin’s summit with an entourage of friends and support crew, Anderson climbed the same peak alone. In the early morning hours, she touched the iconic wooden sign that crowns the mountain, and then started her journey southbound.

While Anderson is understated and under the radar, she is far from underqualified. Even before starting the Appalachian Trail, she had logged 15,000 miles in long-distance hiking. She had conquered hiking’s triple crown — the Appalachian, the Pacific Crest and the Continental Divide Trails — and in 2013 she hiked the 2,663-mile Pacific Crest Trail for a second time, setting the self-supported record on it.

When she completed that hike, in 60 days 17 hours 12 minutes, an average of 44 miles a day, she dethroned Scott Williamson, who had completed the Pacific Crest Trail 13 times and set numerous records on it. Williamson had logged more than 47,000 miles in long-distance hiking. Most F.K.T. followers assumed that Williamson’s trail knowledge, athletic prowess and determination were insurmountable. Then Anderson broke his record by four days.

Over the summer, when Anderson tackled the self-supported record on the Appalachian Trail, she was once again taking on a titan in the F.K.T. field. Matt Kirk had set numerous trail records in the Southeast, and when he broke the Appalachian Trail’s self-supported record in 2013, it was the first time the mark had been lowered in 20 years. Then Anderson broke his relatively new record by four days. Four days.

Anderson said that part of her confidence in going after the record stemmed from her personal observation of male and female hikers at the end of a long-distance trail. “Women appear to be better suited for walking long distances because it doesn’t seem to take the same physical toll on their bodies,” she said. “The women I see at the end of a long-distance hike look fit and badass, but the guys look emaciated.”