Hi Fernando. I get pretty deep into this topic in the book. But in short, I don’t think there is completely honest/integrity. I think a lot of celebrities actually sleep more than they say they do (they say they don’t sleep a lot because they want to seem like super-humans) or, unfortunately, they may use performance-enhancing drugs that pose ethical and health threats.
Anyways, like I said, if this is a topic that interests you, I’d definitely tell you to get the book. Lots more there.