It would appear studies have been done on relative body fat % between male and female long distance athletes. But have they included relative different upper b

It would appear studies have been done on relative body fat % between male and female long distance athletes. But have they included relative different upper body muscle mass between males and females? IF upper body muscle mass differential between genders exceeds the same differential for body fat, perhaps it may explain the declining performance gap between genders over distance? Might male upper body physiology, excess to ultramarathon requirements, become a net negative compared to women’s excess body fat? A human physics and engineering problem that possibly favours females at extreme distance? I’ve got data for hundreds of people travelling 80km, but carrying 25kg. Including female participants. Different story with the additional weight carried though. However, we did have 1 truly exceptional/outlier female who once came in 1st place. Mental resiliency is very much an individual effort. Having a lot of experience assessing humans in this realm, I don’t see any gender based causal factors. However, the one human I met who was truly willing to push themselves to the point of true failure was a female. It was the only time I was nervous in my role. But that is strictly anecdotal.