What do the chest muscles do?
The pectoralis major is a large, fan-shaped muscle across the front of the chest. It pulls your upper arm forward and across your body, which is the main movement in pushing a door, a pram or yourself up off the floor. A smaller muscle, the pectoralis minor, sits underneath and helps move the shoulder blade.
How do you train your chest?
Pressing movements train the chest best: pushing your hands away from your body, either by moving your body (a push-up) or a weight (a bench press). Changing the angle shifts the work slightly. An incline bias works more of the upper chest, and a wider grip gives the chest more of the load than the triceps.