Q: So how much of my muscles is in the lower body? What can I do to exercise my calves and forearm?

A: Your legs and gluteus (aka butt) muscles are the biggest muscle group in your body and are easily 30-40% of the total muscle mass. For your calves you can do standing calf raises or with straight legs extend your toes to push up the 45-degree leg press sled (remember to lock it in place -- this is different from actually doing the leg press exercise) or even simply walk on your toes around the house all day :). For your forearms this and this will take care of your wrist flexors and extensors.