Antagonistic Muscle Pairing refers to one muscle stretching while the other is flexing (contracting). I would usually use this style of training for maximum stress on a body part. For example; I would work bicep and tricep because while I’m curling a barbell for biceps, (flexing/contracting) I’m stretching my tricep. When I’m doing a head-caver I’m lowering the bar to my forehead which flexes the bicep and when you push it up you are flexing your tricep and stretching your bicep. This is called an antagonistic muscle pair. With chest, you work your back which is the same antagonistic action. When you move the weight in the positive motion, you’re flexing the muscle and when you move the weight in a negative motion, you are stretching the muscle.
