Pull-ups are a great exercise for building upper body strength and work a lot of muscles. The main muscles worked during pull-ups are the latissimus dorsi and biceps, which produce the most force in the movement. Other muscles worked during pull-ups include:

• Posterior deltoids: help with posture during the pull and descent, as well as the “squeeze” at the top of the rep.
• Trapezius: helps with shoulder movement and stability.
• Rhomboids: help with shoulder blade retraction.
• Teres major: helps with shoulder adduction.
• Brachialis: located in the upper arm, it helps with elbow flexion.
• Forearms: grip the pull-up bar and help with elbow flexion.
• Core: helps stabilize the body during the movement.

Different pull-up variations prioritize different muscles. For example, wide-grip pull-ups emphasize the lats, traps, and rhomboids, while classic pull-ups emphasize the biceps and brachialis. Chin-ups, which are similar to pull-ups but with an underhand grip, recruit significant help from the biceps, taking some work off the lats.

In summary, pull-ups work a lot of muscles, including the latissimus dorsi, biceps, posterior deltoids, trapezius, rhomboids, teres major, brachialis, forearms, and core.