When you picture strong, well-developed shoulders, you probably think of the front and side deltoids—the muscles that give you that capped, rounded look. However, many people overlook the posterior deltoids, or rear delts. These small but mighty muscles are crucial for both aesthetics and function. Building strong rear delts creates a balanced, 3D appearance and is fundamental for shoulder health and posture.
If your training has left your posterior shoulders underdeveloped, you are not alone. This is a common issue that can lead to muscle imbalances and a hunched-forward posture. Fortunately, with the right approach and a focus on specific movements, you can effectively target and grow this important muscle group. This guide will provide you with the best exercises and strategies to build impressive rear delts.
We will explore the anatomy of the shoulder, the benefits of training this muscle, and a variety of exercises using dumbbells, cables, and machines. Furthermore, we will provide a sample workout and discuss common mistakes to avoid. By the end, you’ll have a complete blueprint for developing your posterior deltoids and achieving a more powerful and balanced physique.
What are the rear delts and why are they important?
The deltoid muscle, which forms the rounded contour of your shoulder, is composed of three distinct sets of fibers, often called “heads.” These are the anterior (front), lateral (side), and posterior (rear) deltoids. The rear delts, or posterior deltoids, originate on the spine of your scapula (shoulder blade) and attach to your upper arm bone (humerus).
Their primary function is transverse abduction, which means moving your upper arm away from the center of your body in the horizontal plane, like when you perform a reverse fly. They also assist in externally rotating the shoulder and extending the arm straight back. Essentially, they are pulling muscles, which is why they are often engaged during back exercises.
Beyond their anatomical function, strong rear delts are essential for maintaining proper posture. In our modern lives, we spend hours hunched over desks and phones, which shortens the chest and front delt muscles while lengthening and weakening the rear delts and upper back. Targeted rear delt exercises help counteract this, pulling the shoulders back into a healthier alignment. This not only looks better but can significantly improve your posture and movement quality.
The science of rear delt growth
To effectively train any muscle, it helps to understand how it responds to different stimuli. The rear delts are composed of a high percentage of slow-twitch muscle fibers. These fibers are more resistant to fatigue and respond well to higher repetitions and more time under tension. This is different from larger muscle groups like the chest or quads, which often have more fast-twitch fibers that respond to heavy, explosive movements.
Therefore, when training rear delts, “ego lifting” with excessively heavy weight is counterproductive. Instead, the focus should be on controlled movements, a full range of motion, and feeling the muscle work. This is where the mind-muscle connection becomes incredibly important. You must consciously focus on initiating the movement with your rear delts, not by shrugging your traps or using momentum from your lower back.
Because they are a smaller muscle group, they recover relatively quickly. This means you can train them more frequently than larger muscles, perhaps two or even three times per week, as part of your shoulder or pull-day routines. Consistent volume with proper form is the key to stimulating muscle hypertrophy and achieving visible growth.
The benefits of strong rear delts
Dedicating specific attention to your posterior deltoids offers a wide range of benefits that go far beyond just looking good from behind. Integrating rear delt exercises into your routine is one of the smartest investments you can make for your long-term joint health and lifting performance.
- Improved shoulder health and stability: Balanced shoulder strength is critical for joint stability. Strong rear delts help to stabilize the humeral head within the shoulder socket, reducing the risk of impingement and other injuries, including a traumatic `posterior shoulder dislocation`.
- Better posture: As mentioned, strong rear delts pull the shoulders back, counteracting the “programmer’s slouch” that is common today. This creates a more confident and upright posture, which can also alleviate neck and upper back pain.
- A complete, 3D shoulder aesthetic: For those interested in bodybuilding, well-developed rear delts are non-negotiable. They add depth and thickness to your upper back and create a rounded, “3D” look for the entire shoulder girdle, making your physique appear complete from all angles.
- Enhanced performance in other lifts: Your posterior deltoids act as stabilizers in major compound lifts. They are crucial for maintaining a stable base during the bench press and provide pulling power in movements like rows and pull-ups. Strengthening them can lead to new personal records across your entire upper body workout.
Top exercises for building your rear delts
To effectively target the rear delts, you need to select exercises that focus on horizontal abduction. It is best to include a variety of movements using different equipment to stimulate the muscle from multiple angles and with different resistance profiles. Here are some of the most effective rear delt exercises.
Dumbbell rear delt exercises
Dumbbells are a fantastic tool for isolating the rear delts because they allow for a natural range of motion. For these movements, always choose a weight that allows you to maintain strict form for 12-15 reps.
- Bent-over dumbbell reverse fly: This is a classic `rear delt exercise`. Hinge at your hips with a flat back until your torso is nearly parallel to the floor. With a slight bend in your elbows, raise the dumbbells out to your sides, squeezing your shoulder blades together at the top. Focus on pulling with your rear delts, not your back.
- Seated bent-over dumbbell reverse fly: Performing the movement while seated can help reduce the tendency to use momentum from the lower body. Sit on the edge of a bench, lean your torso over your thighs, and perform the reverse fly motion. This variation offers greater stability.
- Chest-supported dumbbell row: Set an incline bench to a 45-degree angle and lie face down. Let the dumbbells hang down. Instead of rowing toward your waist, row toward your armpits with your elbows flared out. This angle shifts the focus from the lats to the rear delts and upper back.
Cable rear delt exercises
Cables provide constant tension throughout the entire range of motion, which is excellent for hypertrophy. They are a staple for anyone serious about building their posterior deltoids.
- Face pull: This is arguably one of the best all-around exercises for shoulder health and rear delt development. Set a rope attachment at chest height on a cable machine. Grab the rope with an overhand grip and pull it toward your face, aiming to get your hands by your ears. As you pull, externally rotate your shoulders and squeeze your rear delts hard.
- Cable rear delt fly: Set the pulleys on a cable crossover machine to shoulder height. Grab the right handle with your left hand and the left handle with your right hand. Step back to create tension. With a slight bend in your elbows, pull the handles apart in a wide arc until your arms are out to your sides. This is a superior isolation movement.
Machine-based exercises
Machines offer stability, which allows you to focus purely on contracting the target muscle without worrying about balance. This makes them great for finishing a workout when you are already fatigued.
- Reverse pec-deck machine: Also known as the rear delt fly machine, this is one of the most popular machine exercises for hypertrophy of the posterior shoulder. Adjust the seat so the handles are at shoulder level. Sit facing the machine and grab the handles with a neutral grip. Pull the handles back in a smooth, controlled arc, pausing to squeeze at the peak contraction.
Comparing key exercises: fly vs. row
While both flies and rows can target the rear delts, they do so in slightly different ways. Understanding the distinction can help you program your workouts more effectively. Here is a simple comparison between two popular choices.
| Feature | Bent-over dumbbell reverse fly | Face pull |
|---|---|---|
| Movement type | Isolation | Compound |
| Primary target | Posterior deltoid | Posterior deltoid, rhomboids, external rotators |
| Equipment | Dumbbells | Cable machine with rope attachment |
| Main benefit | Excellent for directly isolating the rear delt for maximum hypertrophy. | Improves overall shoulder health, posture, and hits multiple upper back muscles. |
Sample rear delt workout routine
You can add this routine to the end of your shoulder or pull day two times per week. The goal is to accumulate volume and chase the “pump” with controlled form. Remember to apply principles of progressive overload over time by increasing weight, reps, or sets.
- 1. Face pulls: 3 sets of 15-20 reps. Focus on the squeeze at the end of each rep. Rest for 60 seconds between sets.
- 2. Seated bent-over dumbbell reverse fly: 3 sets of 12-15 reps. Use a light weight and control the eccentric (lowering) phase of the movement. Rest for 60 seconds.
- 3. Reverse pec-deck machine: 3 sets of 15-20 reps. On the final set, perform a drop set: complete the set to failure, immediately reduce the weight by 20-30%, and go to failure again. This is an intense finisher.
Common mistakes to avoid when training rear delts
The rear delts are easy to train incorrectly, which negates the benefits and can even lead to injury. Watch out for these common errors in your training.
- Using too much weight: This is the number one mistake. The rear delts are small muscles and cannot handle heavy loads. Using too much weight forces larger muscles like the traps and lats to take over, defeating the purpose of the exercise.
- Turning it into a back exercise: When performing reverse flies or face pulls, avoid retracting your shoulder blades excessively at the beginning of the movement. While some retraction is natural, the focus should be on the horizontal abduction driven by the deltoid itself. A strong back workout is important, but this is not the place for it.
- Rushing the reps: Momentum is the enemy of rear delt growth. Each rep should be deliberate and controlled, with a distinct pause at the peak contraction. Rushing through the set relies on momentum, not muscle.
- Incomplete range of motion: To fully stimulate the muscle fibers, you need to work through a full range of motion. Make sure you are extending as far back as your mobility allows without arching your back or shrugging your shoulders.
Frequently asked questions
What exercises work the rear delts?
The best exercises for rear delts are those that involve horizontal abduction (moving the arm away from the body). Key examples include the face pull, bent-over dumbbell reverse fly, cable rear delt fly, and the reverse pec-deck machine.
What are the rear delts?
The rear delts, or posterior deltoids, are one of the three heads of the shoulder muscle. They are located on the back of the shoulder and are responsible for pulling your arm backward, rotating your shoulder outward, and stabilizing the shoulder joint.
What are 4 shoulder workouts?
A balanced shoulder workout should include four key movements: an overhead press for the front delts (e.g., dumbbell shoulder press), a lateral raise for the side delts (e.g., dumbbell lateral raise), a reverse fly for the rear delts (e.g., bent-over reverse fly), and a movement for overall health like the face pull.
What are the 3 parts of the shoulder?
The shoulder muscle, or deltoid, is comprised of three parts or “heads”: the anterior deltoid (front), the lateral deltoid (side), and the posterior deltoid (rear). Each part has a different primary function and should be trained for balanced development.
Conclusion
Building strong, well-developed rear delts is not just for aesthetics; it is a fundamental component of a healthy, functional, and balanced physique. By prioritizing these often-neglected muscles, you will improve your posture, enhance your performance on other lifts, and significantly reduce your risk of shoulder injuries.
Remember to focus on strict form, a strong mind-muscle connection, and consistent volume. Choose lighter weights and higher repetitions to ensure the rear delts are doing the work. With the exercises and strategies outlined in this guide, you are now equipped to build the powerful posterior shoulders you’ve been striving for.
For a personalized training plan that incorporates rear delt exercises tailored to your goals, check out the BeFit app. Our AI-powered system can help you create the perfect workout split to achieve balanced growth and unlock your full potential. Keep exploring our blog for more expert tips and guidance on your fitness journey!
