With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.
Neil deGrasse TysonI think I'm misunderstood when I post these comments about films. So here is Kate Winslet sitting on - you know, laying on this plank. This ship is down. She let her boyfriend drown. They didn't even try a second time to get him to float on that with her. So I'm angry by that. I think...
Neil deGrasse Tyson