Well, not sure that the example of East African runners is an exception to the principle, as most of Africa is very much impoverished.

But I've never studied the physiological differences of the different races so maybe there is something, but I know that athleticism is athleticism, and for some reason the champion swimmers, rowers, fencers, etc., don't seem to look like the champion football and basketball players.

That signals a difference in resources to me.