Tough training is kind of an abuse. Why brings sex in the table when they can talk about training abuse on both sex?
(I have a kid of each gender in local gymnastics programs and I have to carefully keep this stuff in mind. It's great that the kids are strong, and gymnastics makes people absurdly strong, but I don't think I would ever let my daughter anywhere near a high-level competitive program.)
Secondly while the strength to weight ratio of women might peak at 15-18, in men it keeps increasing into their mid-late 20s. In general, the strength difference between a 15 and 25 year old man is much much greater than that between a 15 and 25 year old woman. Basically a 20-25 year old man can pull off feats of strength that a 15-16 year old simply can't. The same isn't really true for women (again in general).
My children always liked sport but I told them that this is for their fun and not a medal for the organization (they were never interested in the competition part).
They switched sports either when it was getting boring or they felt that the competition part was over the fun one.
This does not mean that they abondonned early, but for instance both stopped karate after their black belt, to do rock climbing or ping pong. Because the fun was gone.
Our gymnastics club has a kind of parkour club which seems more about having fun and being active which I think me might move my son to when he's old enough.