The bench press is a compound exercise that engages multiple joints and muscle groups simultaneously. While often associated with developing the chest muscles, the lift requires a coordinated effort from the entire upper body. The triceps brachii, located on the back of the upper arm, play a necessary part in successfully completing every repetition. Understanding their specific involvement is essential for maximizing both strength and muscle development during this foundational movement.
The Primary Movers
The initial phase of the bench press is controlled by the primary movers, which drive the weight off the chest. The largest muscle involved is the Pectoralis Major (chest), responsible for horizontal adduction—drawing the arms inward toward the center of the body. Force production from the Pectoralis Major is highest in the lower portion of the lift, immediately after the bar leaves the chest.
The Anterior Deltoids (front portion of the shoulder muscles) are also primary contributors. They assist the chest by performing shoulder flexion, which helps elevate the arm from the bottom position toward the top. Peak activity for both the chest and front deltoids occurs early in the concentric (lifting) phase, providing the initial momentum.
Triceps Role in Pressing Motion
The triceps brachii is classified as a synergist, or helper muscle, in the bench press, supporting the action of the primary movers. The triceps are composed of three heads—the long head, the lateral head, and the medial head—which collectively act as the sole extensors of the elbow joint. Their main function is to straighten the arm, which is the final action needed to “lock out” the weight at the top of the press.
Elbow extension becomes the dominant action in the final half of the upward movement, particularly as the bar approaches full arm extension. If the triceps are weak, the lifter often struggles to complete the last few inches of the press, known as the sticking point. In a standard-grip bench press, the triceps contribute an estimated 22% to 26% of the total force required to move the weight off the chest.
Adjustments for Greater Triceps Focus
To increase the load on the triceps, the exercise mechanics must be altered to emphasize elbow extension over shoulder adduction.
Close-Grip Bench Press
The most effective adjustment is performing the close-grip bench press, placing the hands approximately shoulder-width apart or slightly narrower. Narrowing the grip reduces the mechanical advantage of the chest and increases the range of motion at the elbow joint. This change can increase the triceps’ contribution to an average of about 37% of the total force.
Partial Repetitions
Another method is to limit the range of motion by performing partial repetitions, such as a board press or pin press. Since the triceps are most heavily recruited in the upper half of the press, cutting the movement short ensures they are continually challenged in their strongest range.
Changing the bench angle significantly alters the focus on the chest and front deltoids, but it has a less pronounced effect on the triceps. Studies show that triceps activity remains consistent across flat, incline, and decline angles. Grip width and range of motion are the most direct ways to manipulate the bench press to specifically target the triceps.