> So, are you SURE that an individual that "lived in the prime of their life as a man" is just as strong as they once were once they have spent years on hormone therapy?

Yes. Male puberty confers lifelong physical advantages on the body in terms of muscle mass, heart size, lung capacity and bone density. That's why men dominate women physically in every sport, which is why women have their own special sporting categories so that they stand a chance. Hormone therapy reduces these advantage but it doesn't eliminate them.

> Is it fair to trans athletes?

Probably not, but then is it fair to wheelchair-bound athletes that they're physically incapable of competing with Olympians and so need their own separate event? Maybe the cruel reality of life is that we can't always accommodate everybody?

I don't believe men dominate women in ultra-endurance racing. IIRC though the sample size is quite small it may be that extremely long distance racing actually favors women.

It's always some obscure exception, as if that doesn't prove the rule.

Agreed. Though in this case it seems to me OP is just providing an interesting tidbit. They didn't try to morph that fact into hand-waving of the vast difference in all other sports.

I think most ultra-endurance races tend to have an overall price where everyone competes in the same race.

I recall one race which had an overall price and a women's price. The same person won both and that caused slight kerfuffle.

You don't know what you're talking about. Male hormones in the womb and in puberty confer permanent, drastic changes to muscular power. After training, testosterone levels have very minor effects. An average high school boy athlete could take estrogen for 20 years and still be vastly stronger after that than most female athletes.

> Male hormones in the womb

Can you expand on this? I've not heard of fetuses being affected by androgens before.

> Are you.... sure about this? Like how sure are you? What do you think you know?

> The human body changes surprisingly fast. Astronauts that stay in outer space for too long can't even walk when they return to earth. That "too long" is like... a year basically.

> A "lifetime" of muscle mass will last for how long once someone starts taking androgen blockers then estrogen?

You raise a very fair question, but we have sufficient data to really support either position at the moment?

Do we have a way of knowing when an individual (or group of individuals) would have lost the ‘benefits’ to make competition truly fair?

Not just as strong, but there does remain an advantage. TFA goes into this:

> Vanbellinghen, 27, whose qualifying efforts were disrupted by injury, pointed out that the retained benefit of taking steroids, even years earlier, is widely known.

It's easier to regain lost muscle mass than it is to gain it in the first place.