When you use the push/pull approach, you focus on “pull” exercises one day and “push” exercises the next day. Pull exercises focus on muscle groups that contract as the weight is pulled toward the body and lengthens as the weight is extended away from the body (i.e. chin-ups). Conversely, push exercises focus on muscle groups in which muscle tissue contracts when the weight is pushed away from the body and lengthens as the weight is returned back towards the body (i.e. chest presses).