The posterior deltoid, commonly called the rear delt, is the muscle group situated on the backside of the shoulder complex. It is one of three distinct heads that form the deltoid, alongside the anterior (front) and medial (side) portions. This muscle often remains underdeveloped compared to its counterparts, a lack of balance stemming from training routines that prioritize pushing movements like the bench press and overhead press. The rear delts are primarily responsible for moving the arm backward (extension) and for horizontal abduction, which involves pulling the arm away from the midline of the body.
Why Rear Delt Focus Is Important for Shoulder Health
Training the posterior deltoid is important for maintaining a healthy and functional shoulder joint. Strong rear delts contribute significantly to shoulder stability, helping to keep the humerus centered in the socket during dynamic movements. They work alongside the rotator cuff muscles to provide external rotation and deceleration control for the arm. Neglecting this muscle can lead to muscular imbalances that increase the risk of injury.
Developing the rear delts also improves overall posture. Excessive training of the chest and front shoulders can pull the shoulders forward, contributing to a rounded appearance. By strengthening the posterior chain, the rear delts help pull the shoulders back and keep the scapulae retracted, counteracting this forward pull.
Quantitative Guide to Rear Delt Training Volume and Frequency
The question of “how many exercises” is best answered by focusing on total weekly volume, which is the number of hard working sets performed. For most people looking to build muscle, the effective volume range for the rear deltoid is between 6 and 12 sets per week. This range balances the work needed to stimulate growth with the maximum amount that allows for recovery. Beginners should start at the lower end, while advanced lifters may explore the upper limits.
A practical approach is to select one or two isolation exercises and perform them two to three times throughout the training week. Distributing the volume this way is more effective than trying to perform all sets in a single session, as it allows for better recovery and higher quality work.
The rep range should be tailored to the rear deltoid’s function. These muscles respond better to moderate to high repetitions, with a range of 10 to 20 reps per set recommended. Using lighter weights and higher reps helps emphasize the mind-muscle connection and prevents larger muscles like the upper back from taking over. Prioritizing a controlled contraction and full range of motion is more productive than lifting heavy weight.
Essential Rear Delt Exercise Categories and Execution
Effective rear delt training focuses on two primary movement patterns: horizontal abduction and combined abduction with external rotation.
Horizontal Abduction (Reverse Fly)
The most common exercise in this category is the Reverse Fly, which can be performed with dumbbells, cables, or a reverse pec deck machine. When performing this motion, focus on initiating the movement by squeezing the shoulder blades together, not just moving the arms. Keep a slight bend in the elbow and stop the movement once the arms are parallel to the torso to maintain tension on the target muscle.
Abduction with External Rotation (Face Pull)
The second effective category involves movements that combine shoulder abduction with external rotation, most notably the Face Pull. This exercise is performed with a rope attachment on a cable machine, pulling the rope toward the face or forehead. The simultaneous external rotation, which occurs as the hands are pulled apart near the head, makes the face pull excellent for strengthening the external rotators and improving shoulder alignment.
To maximize the recruitment of the rear deltoids and minimize involvement of the upper trapezius, the elbows should lead the movement and remain elevated. Select a weight that allows for strict form and a momentary peak contraction at the end of the range of motion.