What Muscles Do Push-ups Build?

You are probably aware that push-ups work the muscles of your chest. You may even know that these muscles are referred to as the pecs. Push-ups do a lot more than just build up the chest muscles. Push-ups also require the use of certain muscles in the shoulders and arms, according to the Aerobics and Fitness Association of America (AFAA).

Pecs

The pecs refer to the muscles in the chest properly called the pectorals, which includes the pectoralis major and minor. Push-ups mainly use the pectoralis major, which is one of the muscles responsible for horizontally flexing the shoulder joint. The pectoralis minor, on the other hand, works to abduct and internally rotate the shoulder, which is not a movement that is done during a push-up but may be worked by doing another chest exercise called a chest flye. According to AFAA, horizontal flexion of the shoulder describes the action of bringing the shoulder closer to the midline of the body along the horizontal plane, which is what happens when your press yours straight to lift your body during a push-up.

Anterior Deltoids

The deltoid muscles are those in the front, middle and rear of the shoulders. The anterior deltoids are the other primary mover that allows for horizontal flexion of the shoulder during the up phase of a push-up. Anterior simply means front. The rear and medial (middle) delts are not targeted by a push-up, though they act as stabilizers and antagonists. All that means is that these muscles are either work with or in opposition to the prime movers. The prime movers are the muscles that actually get toned from an exercise.

Triceps

The triceps are muscles located in the back of your upper arms. Their full name is actually the triceps brachii and should not be confused with the triceps surae, which is a muscle of the lower leg. There are three parts or heads of the tricep muscles. These are called the long, lateral and medial heads. They all are worked during a push-up. The triceps job is to extend the elbow. Extension is done when the movement of a joint makes the angle between two bones greater. During a push-up, this is during the up phase of the exercise as the bones in the upper and lower arms are moved further apart when the arms are straightened.