I have a kind of tight schedule. I have school and I walk home so I get home at 3:00 - 3:30. Then I eat and check my emails and such. Then I walk my dog for 1 hour. Then I do my homework and hang out with my friends. So I get back at like 8. What is a good hour long work out? Im not fat, I just want to build up mucle. Thanks so much ?