The posterior deltoids, or rear delts, are located at the back of the shoulder joint, forming one of the three heads of the deltoid complex. While the front and side deltoids receive attention in most training programs, the posterior head is frequently neglected, leading to muscular imbalances. Training this muscle group is important for both physical performance and a balanced physique. This article provides guidance on how to strengthen and build the posterior deltoids effectively.
The Importance of Posterior Deltoids
Training the rear deltoids is fundamental for maintaining overall shoulder health and stability. These muscles are primarily responsible for horizontal abduction—drawing the arm away from the midline of the body in a horizontal plane—and external rotation of the shoulder joint. This function is important for everyday actions like pulling, rowing, and reaching behind the body.
An overemphasis on chest and anterior shoulder training often pulls the shoulders forward, creating a rounded posture. Strengthening the posterior deltoids helps counteract this imbalance by pulling the shoulder blades back and stabilizing the shoulder girdle. This action promotes a more upright posture and helps prevent forward-shoulder positioning that can contribute to pain or injury. They also work with the rotator cuff to stabilize the shoulder joint during heavy pressing movements.
Effective Exercises for Targeting the Rear Delts
The most effective approach to developing the posterior deltoids involves exercises that isolate their primary function of horizontal abduction and external rotation. These movements allow for a focused contraction that minimizes the involvement of larger back muscles. Incorporating two or three of these exercises into a routine can improve rear delt development.
Face Pull
One highly utilized exercise is the Face Pull, typically performed using a cable machine with a rope attachment set at face or neck height. Step back to create tension and pull the rope toward your face, externally rotating your hands so your knuckles point upward at the end of the movement. This exercise combines horizontal pulling with external rotation, effectively targeting the rear delts and the rotator cuff muscles.
Dumbbell Reverse Fly
Another foundational movement is the Dumbbell Reverse Fly, which can be performed bent-over or seated with the chest supported on an incline bench. For the bent-over variation, hinge at the hips with a slight bend in the knees, letting the dumbbells hang with palms facing each other. Raise the arms out to the sides, leading with the elbows until they are level with the shoulders. The supported version removes the need for lower back stabilization, allowing for stricter isolation.
Band Pull-Apart
A simpler, highly effective isolation exercise is the Band Pull-Apart, requiring only a resistance band. Hold the band with both hands extended straight out in front of the chest, then pull the band apart until your arms are fully extended to the sides. The resistance band provides accommodating resistance, meaning tension increases as the rear delts contract and the band stretches. This exercise is an excellent warm-up or finisher due to its low impact and high activation.
Mastering Form and Avoiding Common Mistakes
Achieving maximal rear delt activation depends more on precise form and a strong mind-muscle connection than on lifting heavy weight. A common error in the Face Pull is shrugging the shoulders toward the ears, shifting the work to the upper trapezius muscles. To correct this, focus on keeping the shoulders down and initiating the pull by driving the elbows back, aiming to bring the rope between the eyes and the forehead.
When performing Dumbbell Reverse Flyes, a frequent mistake is using momentum or excessive weight, which causes the torso to swing and recruits larger upper back muscles. The movement should be slow and deliberate, especially during the eccentric (lowering) phase. Maintain a slight, fixed bend in the elbows throughout the entire range of motion. Concentrate on squeezing the shoulder blades together, which cues the rear deltoids to contract, rather than focusing on lifting the weight.
The rear delts respond well to maintaining continuous tension on the muscle during both cable and dumbbell variations. Allowing the weight stack to touch down or the dumbbells to rest at the bottom releases tension and reduces the training stimulus. Imagine pulling with your pinkies or the back of your hands, as this mental adjustment often improves external rotation and rear delt engagement. The weight chosen should be light enough to allow a controlled pause and peak contraction at the point of maximal rear delt shortening.
Integrating Rear Delt Work into Your Routine
The posterior deltoids have a fast recovery rate and are relatively small, meaning they benefit from a higher training frequency than larger muscle groups. Including targeted rear delt work two to three times per week is an effective recommendation for building strength and size. This frequency allows for consistent stimulus without excessive fatigue accumulation.
A higher volume of repetitions per set is recommended to maximize blood flow and time under tension. Sets should be performed in the 12 to 20 repetition range. This lighter weight, higher-rep approach is conducive to focusing on the mind-muscle connection and precise execution.
The placement of rear delt exercises within a workout can influence their effectiveness. Many lifters perform them early in a workout, perhaps before heavy pressing movements, as a warm-up to activate the shoulder stabilizers. Alternatively, they can be integrated into “pull” days or performed as a superset with exercises for the chest or front deltoids. This ensures they receive dedicated attention rather than being relegated to a quick, fatigued finisher.