The posterior deltoid, commonly known as the rear delt, is the triangular muscle located at the back of the shoulder. Training this head is important for creating balanced shoulder development and improving the overall aesthetic of the upper body. This article focuses exclusively on effective techniques for targeting the rear delts using only dumbbells.
Why Target the Rear Deltoids?
The primary functions of the posterior deltoid involve shoulder extension and horizontal abduction, which means pulling the arm backward and moving it away from the midline of the body in the horizontal plane. These muscles are heavily recruited during pulling motions, aiding in overall upper body strength and stability. Neglecting the rear delts can lead to muscle imbalances, especially if the anterior (front) deltoids and chest muscles are overdeveloped.
This imbalance often results in a forward-rounded shoulder posture, which can increase the risk of injury. By strengthening the rear delts, you effectively help stabilize the shoulder joint and counteract this internal rotation. Training this muscle group specifically helps maintain proper joint mechanics and contributes to a healthier, more upright posture.
Step-by-Step: The Bent-Over Reverse Fly
The bent-over reverse fly, also called the dumbbell rear lateral raise, is one of the most direct ways to isolate the posterior deltoid using dumbbells. Begin by standing with a dumbbell in each hand and hinge forward at the hips while maintaining a neutral, flat back. Your torso should be close to parallel to the floor, or as far as you can comfortably manage while keeping the spine straight, with a slight bend in your knees. Let the dumbbells hang straight down toward the floor, with your palms facing each other in a neutral grip.
Initiate the movement by raising the dumbbells out to the sides, moving them through an arc until your upper arms are roughly parallel to the floor. Focus on driving the movement with your rear shoulders, imagining you are pushing your arms away from your body rather than simply lifting the weights. Your elbows should remain slightly bent throughout the range of motion, and you should aim to keep the movement within the shoulder joint itself, minimizing involvement from the scapula retractors.
Exhale as you lift the weights, pausing briefly at the top to consciously squeeze the rear deltoids. Slowly and deliberately lower the dumbbells back to the starting position, controlling the weight on the eccentric (lowering) phase. Avoid using momentum or swinging the weights, as this reduces the tension on the target muscle.
Alternative Dumbbell Rear Delt Variations
While the bent-over fly is effective, alternative positions can alter the resistance curve and help maintain tension on the rear delts.
Prone Incline Bench Dumbbell Rear Delt Raise
Set an adjustable bench to an incline angle between 30 and 45 degrees, and lie face down with your chest pressed against the backrest. This supported position removes the need to stabilize the lower back, making it easier to isolate the rear delts and preventing momentum from the hips. Perform the raise identically to the bent-over version, raising the dumbbells out to the side until the arms are parallel to the floor.
Seated Dumbbell Rear Delt Raise
Sit on the end of a bench and lean forward, resting your chest against your thighs or knees. This variation offers a different torso angle and also limits the ability to cheat by using the lower back or legs.
Maximizing Results and Avoiding Injury
To maximize the effectiveness of rear delt training, the emphasis must be placed on technique and muscle connection over the amount of weight used. The posterior deltoid is a small muscle group, and using excessively heavy dumbbells will cause the larger back muscles, like the traps and rhomboids, to take over the movement. Select a weight that is significantly lighter than what you use for lateral raises.
Avoid shrugging the shoulders toward the ears during the lift, as this activates the upper trapezius muscles and pulls tension away from the rear delts. Focus on keeping the shoulders depressed and concentrating on the sensation of the rear deltoid contracting. Programming these exercises at the beginning of a shoulder or pull workout, when the muscles are fresh, can enhance focus and engagement. Aim for higher repetition ranges, typically between 12 to 20 repetitions, to fully fatigue the muscle fibers and promote growth.