Question: Why is the human body efected in space

Julia Attias answered on 7 Dec 2015:

Hi @Comet_finder119,

I have just looked at your profile – you want to be either a personal trainer or a scientist when you grow up – I am both! They are both great in their own ways.

The human body Is affected primarily because of the lack of gravity. If you think about it, every single day, all the different systems in your body are working against gravity, fighting it away with everything we do. Your heart works against gravity to pump blood up to your head. Your muscles and bones in your legs work against gravity to keep you standing up. So once you take that gravity away, those systems don’t have to work as hard anymore, which may sound like a nice thing and that they can relax, which isn’t too far from the truth! They do far less work, which is great if they were going to stay in space forever, But they come home, and they need to face gravity again, and all of those systems need to be strong again. Luckily with the use of exercise and other countermeasures, they recover quickly!