We have a specific core of exercises that work those three parts of the body. The most effective method in training a baseball player is a series of combination sets. Focus in on one of those anatomical parts and do a series of exercises before you go onto another anatomical part. Doing a combination series, a multiple set, and different back exercise variations ensures the player that his back muscles are fully developed. And we do the same thing for the other two areas, namely the stomach and legs.
Baseball also requires flexibility - much of the action involves quick rotation.
We do something we think is very novel in Atlanta. We expect our players to spend a lot of time swimming, doing aquatic exercises. The theory of swimming exercises is to stretch, to strengthen the muscle without any risk of joint pressure. If you define strengthen as stretching without risk of joint pressure, you need to know what specific exercises need to be performed in the pool. Sometimes you see specific exercises in aquatic class, that's not what you are trying to accomplish in baseball development.