What are some ways to gain arm and leg muscle, without the gym?

Plyometric training: You must be in good enough shape to participate in the plyometeric exercises. If done consistently and regularly, you can build muscle and strength at a faster rate than some other training regimens. There is a higer rate of injury reported with these exercises when unsupervised so i would recomend a trainer or exercise physiologist to guide you through a safe work out for you to meet your goals.