I too wonder about recovery time etc, but from what I understand of what Steve has already accomplished over the past 24 years, he doesn't wonder; he already knows. So those of us thinking this is something he is going to be exploring/discovering/learning over the coming year are probably (I dare to say) wrong: Recovery is not "the Test". Recovery, for Steve, is already a known, a given, a familiar friend.
Of course, this doesn't stop me wondering about how he does it but my doubt/fear/worry/whatever is informed by my knowledge of my body, wondering what I'd need to do if it were me attempting this challenge. Fact is, I don't know what I'd need because I've never attempted even one tiny miniscule portion of all the stuff Steve has already succeeded at doing. At the end of the day, what I "wonder" isn't relevant. Because it's not me doing it - it's Steve. And I am not Steve.