The human body is over 70% water. Every cell in the body is surrounded by fluid and when you get a massage, the fluid in your muscles is manually moved and pushed around. You would get the same effect with a full body work out at the gym, if you flexed and stretched every muscle in your body.
Humans need sleep; everybody knows that without it, we get cranky, a bit loopy, and then we die. Unfortunately, science has been a little iffy about it; though we understood the negative effects associated with lack of sleep, no one really knew why those things happened. Now, we’re finally getting some insight into what sleep does for our bodies.