The flat barbell bench press is a compound exercise that primarily targets the muscles of the chest, shoulders, and triceps. It also engages several other muscles in the upper body and core for stability and support. Here are the main muscles worked during the flat barbell bench press: 1. Pectoralis Major: The pectoralis major, or chest muscles, are the primary muscles targeted during the flat barbell bench press. They are responsible for horizontal adduction of the arms and play a significant r