Does the biceps contract during the bench press?

Generally speaking, the biceps brachii are engaged during the bench press. The detailed explanation is as follows:

The bench press is an upper-body exercise primarily targeting the pectoralis major, pectoralis minor, and triceps. The biceps brachii, located on the front of the upper arm and attached to the scapula and radius, contribute to additional stability during the bench press by helping stabilize the upper limbs. This helps prevent excessive swinging or movement, allowing force to be more effectively concentrated on the chest muscles and triceps. At the same time, activation of the biceps helps maintain proper bench press form. The biceps play a certain controlling role, ensuring that the arms remain in the correct position and angle throughout the pressing motion, thus maintaining proper technique and maximizing training effectiveness. Moreover, although the chest muscles and triceps are the primary movers in the press, involvement of the biceps can enhance overall pressing power. When lifting a barbell or dumbbell, contraction of the biceps provides supplementary strength, assisting the chest and triceps in completing the movement. Therefore, the biceps brachii do need to exert force during the bench press.

It is recommended to choose an appropriate weight for the bench press to avoid using excessive load, which may lead to poor form, inaccurate technique, and increased risk of injury.