Ok, but that is just asserting that mental toughness is what matters here. And it ignores the fact that there are far more men in the slightly less than ultra

Ok, but that is just asserting that mental toughness is what matters here. And it ignores the fact that there are far more men in the slightly less than ultra marathon world than women, so shouldn't there also be more men with a chance to win if mental toughness is equally distributed? Maybe it's the fact that women have a higher percentage of type 1 muscle fibers than men, and it just takes until ultra marathon level distances that the increased proportion of type 1 fibers makes up for the relative higher percentage of type 2 fibers in men. Or maybe women are more efficient at burning fat than men are.