A huge part of his natural talent is robustness. This is what enables him to put in consistent training and optimize his fitness. It's a big part of why we know who he is.
Also, I think your information is flawed:
From the videos I've watched, it seems like he takes his athletic massages seriously. And I get the impression that part of his disciplined mentality is to consistently take care of the small stuff . He also takes post-race vacations to let his body and mind recuperate. And years or running helps prevent certain types of injury.
PS: Since he's not skin and bones (relative to others in the sport), he's clearly eating more than two slices of bread to recover from his training.