Shoulder Press and the Primary Muscles

Training your shoulders will help give the illusion that you have a smaller waist and can help create the v-taper look -- broad shoulders that taper into a thinner torso -- that is coveted by both body builders and everyday people. Adding the shoulder press to your workout is a way to attain well-developed shoulders because it targets all of the shoulder muscles in one move.

The traditional shoulder press is performed in the sitting position, holding a pair of dumbbells. Sit with your back straight and chest pushed forward. Hold a dumbbell in each hand. Bring the dumbbells just above your shoulders, with your elbows below your wrists. To execute the exercise, exhale and press the dumbbells directly upward until your arms are fully extended above your head. Inhale as you slowly lower your arms to the starting position just above your shoulders and repeat. Perform two to three sets of eight to 12 repetitions of the press during your workout.

The main muscle targeted by the dumbbell shoulder press is the anterior deltoid, or the front shoulder. To a slightly lesser degree, the exercise also hits the remaining deltoid muscles, including the lateral deltoid, or the outside of your shoulder, and posterior deltoid, or the back of your shoulder. The triceps, or back of your arms are also considered to be primary muscles because they assist in the pressing action.

Performing the shoulder press requires other muscles to help stabilize and support your deltoids. Your rotator cuff, the group of small muscles and tendons surrounding your shoulder joint are activated in this exercise. Also, your trapezius or traps, latissimus dorsi or lats and your rhomboids, all in your back offer assistance throughout the movement. Meanwhile, your rectus abdominis (abs) and your transverse abdominis in your core help to stabilize you and remain engaged as you slowly lift and lower the weight.

The shoulder press can be modified so that it targets your muscles differently. Holding a barbell with an overhand grip across your chest and pressing upward, also known as a military press, targets the same muscles as a regular press as well as your pectoralis major, the upper chest muscles. Performing the exercise while standing or one arm at a time will also force your core muscles, including your abs, to work harder to stabilize your body.