The side raise, also known as the lateral raise, is a popular isolation exercise focusing on the shoulder musculature. This movement involves lifting resistance, typically dumbbells, out to the sides until the arms are roughly parallel to the floor. It is a foundational exercise designed to increase shoulder width and create a rounded, defined appearance. The goal of a side raise is to minimize the involvement of larger muscle groups, isolating the smaller, highly visible shoulder muscles.
The Primary Muscle Target
The primary muscle activated during the side raise is the medial deltoid head, often called the lateral deltoid. This head is situated on the side of the shoulder and is responsible for shoulder abduction—moving the arm away from the midline of the body. Maximizing the development of this specific muscle head creates the “capped” or broad-shouldered look.
The deltoid muscle has three heads: anterior (front), medial (side), and posterior (rear). While the medial deltoid is the main mover, the anterior deltoid is also involved as the arm begins to lift. The upper trapezius (traps) acts as a synergist, stabilizing the shoulder blade during the movement. Proper execution is designed to maximize the isolation of the medial head while minimizing contribution from the anterior deltoid and the trapezius.
Proper Execution and Technique
The standard side raise is performed while standing with a dumbbell in each hand, held at the sides with palms facing the body. A slight bend in the elbows should be maintained throughout the movement to reduce strain on the joint and maintain tension on the target muscle. The core should be braced to prevent the torso from swaying.
To initiate the lift, raise the dumbbells out to the sides, leading the movement with the elbows, not the hands. The upward phase should stop when the arms are approximately parallel to the floor, or slightly below shoulder height. Raising the weights higher than this point transfers the load away from the medial deltoid and onto the upper trapezius.
The most effective part of the exercise occurs during the eccentric, or lowering, phase. The weights should be lowered slowly and with control, resisting the pull of gravity for a count of two to three seconds. This controlled negative motion maximizes the time the medial deltoid spends under tension. Completing the repetition by gently bringing the weights back to the starting position ensures continuous tension.
Refining the Movement
One of the most common errors that reduces the effectiveness of the side raise is using excessive momentum, often called “swinging” the weight. Swinging occurs when the weight is too heavy, forcing the lifter to recruit the back and hips to jerk the weight up, which shifts the work away from the medial deltoid. Using a lighter weight that allows for a strictly controlled path is far more productive for the intended muscle target.
Another technique refinement involves body positioning to ensure better isolation. Standing completely upright can sometimes shift the focus toward the anterior deltoid. To counteract this, some lifters benefit from a slight forward lean of the torso, which more effectively aligns the medial deltoid fibers with the resistance.
Advanced variations, such as the cable side raise, offer a way to maintain constant tension throughout the entire range of motion, unlike dumbbells where the tension drops significantly at the bottom. Seated side raises or bracing against a support can also be used to eliminate any possibility of using momentum from the lower body.