[Seloria]

Wow at 21 she should be able to walk quite a while without feeling tired or winded. I admit I'm only in one sort of shape and that's round, but even I can walk forever. I have to take it slow cause I've had asthma since I was a kid (nothing to do with my size) but I don't easily get tired. Is she normally not active at all? If you don't move much throughout your day, your muscles sort of "forget" how to work and you'll get tired from the smallest things a lot easier.