His test levels have ABSOLUTELY declined from when he was 18 or 19. There's no doubt about that. Keeping in shape, and even more so, fighting shape, at 46 is a Sisyphean task, and that's due mostly to test levels dropping.
I am sure his recovery is affected by it, and even BHop, who's one of the most self-assured, boisterous fighters I've ever seen, admits openly that he's lost a step. He doesn't win fights in the same way anymore- he's much more offensive now than he used to be, because he has to be.
And nearly all of them are on massive amounts of steroids, which effectively counteract the normal dropping of testosterone.
I admit that it's easier for me to build muscle now at 27 than it was at 18- but that's more because my metabolism dropped and my job changed, meaning that for once, I can put on weight where before, it was nearly impossible.
I don't believe it's because my test levels are the same as when I was 18 though. I can nearly guarantee they're probably not, although they're also probably not far off either because I'm not that old.