I do wake up naturally, but I've noticed I sleep less and less. I used to swear by at least 7 hours of sleep every night, but somehow, I'm down to 6 these days without really feeling tired. I just hope I am not doing harm to my body by sleeping less and less.

It's hard to choose, I think both are equally important. They affect each other bidirectionally. But brains before body, I guess, if I really have to choose. So sleep it is.