Eccentric & Concentric Motions in a Shoulder Press

Familiarizing yourself with common weight training terminology can help you understand how to train more efficiently. For example, you might read about the proper timing of the eccentric and concentric movements in your chosen exercises. To perform exercises such as the shoulder press properly, you must maintain the correct timing and form in both your upward and downward movements.

You can perform a shoulder press in numerous ways, using a variety of tools. You’ll typically do shoulder presses while seated, to better target your shoulder muscles, but you can also perform them while you’re standing. You can do shoulder presses with a barbell or dumbbells, or on a shoulder press machine. To perform a seated barbell shoulder press, sit up straight with your feet flat on the floor and hold the bar with an overhand grip in front of your shoulders, with your hands about shoulder-width apart and your elbows pointed down. Exhale as you extend your arms straight over your head, then inhale as you lower the weight to the starting position.

The shoulder press targets the anterior deltoid muscle in the front of your shoulder. It also works the lateral deltoid on top of your shoulder, your triceps, the serratus anterior along the sides of your rib cage, plus several upper back muscles. If you spread your hands wider on the barbell you put more emphasis on your triceps, but you also increase the risk of a shoulder injury. If you perform the exercise on a machine and have your choice of grips, select a neutral grip, with your palms facing each other, if you wish to further isolate the anterior deltoid.

The concentric motion in a weight training exercise occurs when your muscles become shorter and develop tension. This typically results from lifting or pushing the weight up, against gravity. As with most free-weight exercises, the concentric motion during a shoulder press occurs when you’re pressing the weight above your head. Stop your motion just before you lock your elbows if you wish to maintain the maximum tension on your anterior deltoid.

The eccentric motion in a weight training activity occurs when your muscles lengthen while they’re under tension. This type of contraction typically results from lowering the weight. In the shoulder press, the eccentric motion occurs as you’re descending back to the starting position. As with most weight training activities, lower the weight slowly and under control when you’re performing the shoulder press. More of your muscle fibers are engaged during the concentric phase of a weight training exercise, but more fast twitch fibers are engaged during the eccentric phase. To build maximum strength quickly, therefore, perform the eccentric phase of the shoulder press alone. Have a workout partner help you lift the weight over your head, then lower it to your chest on your own.