Although the pushup garners most of its fame for working the upper body, this classic exercise actually engages unexpected muscles, from the abdominal core to the lower back. As a body-weight exercise, the pushup requires no equipment and offers benefits as wide-ranging as heightened arm strength, increased muscle definition and improved bone density.
The pushup chiefly targets the chest, shoulders and triceps, the muscles on the back of the upper arm. In the chest area, pushups work the pectoralis major, the thick, slab-like muscles that span from the collarbone to the upper ribcage. As the shoulders drive the motion of raising and lowering your body, the pushup focuses on the main muscle of this body part, the deltoids. Pushups specifically work the anterior - or front - deltoids, but they also engage the medial - or rear - deltoids.
At the top of the motion, the pushup challenges you to hold your body in place. This element of the exercise engages the muscles of the core, neck, hips and legs. The core muscles of the rectus abdominis, the outer torso obliques and quadriceps muscles of the thigh all act as stabilizers to help your body maintain a balanced horizontal position. The erector spinae, which spans from the neck to the tailbone, gets a workout as an antagonist stabilizer, a muscle that promotes joint stabilization by countering the force of rotating joints. Other secondary muscles worked by pushups include the rhomboids, rotator cuff, serratus anterior and gluteus maximus.
Variations of the standard pushup bring certain muscles to the forefront. Widening the grip of your pushup specifically targets the chest and triceps, and a closer grip - known as the diamond or triangle pushup - focuses mostly on the triceps. For experienced exercisers, adding a clap to the pushup when you lift your body upward gives the pectorals an intense workout and builds explosive strength. Performing pushups with your hands on an incline targets the shoulder muscles.
You'll only reap the benefits of the pushup if you practice proper form, so if you're new to the exercise, enlist a certified trainer or fitness professional to teach you the basics. Although proper pushups work many parts of the body, improper form can lead to injuries including inflammation of the shoulder muscles and strained wrists. Avoid injury by practicing correct form and performing full-body loosening warm-ups and dynamic stretches before your workout.