Barbell bench press

Barbell and bench

The classic horizontal press. The pectoralis major drives the bar up, the front deltoids assist at the shoulder, and the triceps finish the lockout.

What each muscle does in the barbell bench press

Muscle	Role	Action
Pectoralis major	Primary	Flexes, adducts and medially rotates the arm
Anterior deltoid	Secondary	Flexes and medially rotates the arm at the shoulder
Triceps brachii	Secondary	Extends the elbow; the long head also extends the arm

Primary muscles are the prime movers; secondary muscles assist or stabilise. The balance shifts with grip, stance, range of motion and technique.