The Hex Press, often called the dumbbell squeeze press or crush press, is a compound upper-body exercise targeting the pectoral muscles, shoulders, and arms. Performed lying on a bench, the lifter holds a dumbbell in each hand with a neutral grip directly above the chest. The defining characteristic is the continuous, forceful inward pressure applied to the dumbbells as they are pressed upward and lowered. This sustained tension throughout the full range of motion is what makes the Hex Press unique.
Primary Chest Engagement
The primary muscle group activated during the Hex Press is the Pectoralis Major, the large, fan-shaped muscle that makes up the bulk of the chest. This muscle is the prime mover responsible for the horizontal adduction of the shoulder joint—the action of bringing the upper arm across the front of the body. Unlike a traditional dumbbell press, the Hex Press requires the lifter to actively press the weights inward against each other simultaneously with the upward press. This constant inward pressure forces continuous muscular adduction, which is the exact function of the pectorals.
This specific adduction mechanism places greater emphasis on the sternal head of the pectoralis major, which constitutes the fibers in the inner region of the chest near the sternum. The continuous squeezing action maximizes the recruitment of these inner chest fibers, providing a different training stimulus than wide-grip variations. By maintaining tension in the shortened range of motion, the Hex Press increases the time the muscle spends under tension, promoting muscle hypertrophy. The Pectoralis Minor, a smaller muscle situated beneath the pectoralis major, also works to help depress and stabilize the shoulder blade during the movement.
Shoulder and Arm Involvement
While the Hex Press is a chest-dominant movement, the anterior deltoids and triceps brachii act as powerful synergistic muscles to assist the pressing action. The anterior deltoids, located on the front of the shoulder, contribute to the shoulder flexion required to lift the weights towards the ceiling. Their primary role is to assist the pectorals in the initial push off the chest and maintain the vertical trajectory of the movement.
The Triceps Brachii, located on the back of the upper arm, are heavily recruited for elbow extension, which is the action that straightens the arm to complete the press. Due to the close, neutral grip mandated by pressing the dumbbells together, the Hex Press resembles a close-grip bench press variation. This inherently increases triceps activation compared to a standard, wider-grip press. The long, medial, and lateral heads of the triceps contract forcefully to lock out the weight at the top of the movement.
The Unique Role of Stabilization and Squeeze
The defining feature of the Hex Press is the continuous isometric contraction created by the squeeze, which engages various stabilizing muscles throughout the upper body. The constant inward force on the dumbbells creates instability that requires the rotator cuff muscles to work harder to maintain shoulder joint integrity. These smaller muscles must fire continuously to keep the humerus head securely centered in the shoulder socket against the adduction force:
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
Maintaining a stable position on the bench while executing the movement requires the engagement of the core musculature, including the rectus abdominis and obliques. These muscles work to resist rotation and hyperextension of the lower back, ensuring that the force generated during the press is efficiently transferred into the weights. The forearms and grip flexors are also continuously engaged to maintain the crush grip on the dumbbells throughout the entire set.