The Best Rear Delt Exercises You’re Probably Skipping

Ever wondered why your shoulders still look flat from the side, no matter how much you bench and press?

If that sounds familiar, you’re not alone. As a certified personal trainer, I see this almost every week. Someone has been training hard for months, their chest and front shoulders are growing, but their shoulders still don’t look “round” or three-dimensional. Nine times out of ten, the missing piece is the same: the rear delts.

Rear delts are small, but they carry a lot of weight when it comes to how your shoulders look, how you move, and how well your joints hold up over time. And yet, they are one of the most skipped muscles in the gym. In this guide, I’ll break down exactly what rear delts are, why they get ignored, and which exercises actually work them the way they’re supposed to be worked.

What Are Rear Delts, Exactly?

Your shoulder, or deltoid muscle, is made up of three separate sections, often called “heads”:

• Front (anterior) delt – lifts your arm forward, works hard during pressing movements
• Side (medial) delt – lifts your arm out to the side, gives shoulders that rounded cap
• Rear (posterior) delt – pulls your arm backward and helps rotate the shoulder

The rear delt, or posterior deltoid, sits at the back of your shoulder. Its main job is horizontal abduction, which is just a technical way of saying it pulls your arm backward and away from your chest, like when you row a weight toward your body or pull your elbows behind you.

It also works closely with the rotator cuff muscles, especially the infraspinatus and teres minor, to keep your shoulder joint stable and controlled.

Because it’s smaller than the other two heads, the rear delt is easy to under-train without even realizing it.

Why Rear Delts Get Neglected

Most training programs are built around pushing movements: bench press, overhead press, push-ups. These exercises hammer the front and side delts but barely touch the rear delts.

Pulling exercises like rows and pulldowns do involve the rear delts, but usually as a helper muscle, not the main target. Your back and biceps tend to take over the work before the rear delts get properly fatigued.

On top of that, rear delts are hard to “feel.” Most people have a strong mind-muscle connection with their chest or biceps because they can watch those muscles work in the mirror. You can’t really see your rear delts contract, so it’s easy to go through the motions without actually training them hard.

The result is a classic case of “out of sight, out of mind.”

Why Training Rear Delts Actually Matters

This isn’t just about aesthetics, although that’s a big part of it. Here’s what’s really at stake:

Posture. Weak rear delts are strongly linked to rounded, hunched shoulders. One frequently cited study found that a large majority of adults aged 20 to 50 show some degree of rounded shoulder posture, and modern desk work and phone use only make this worse. Research on office workers also shows that neck, shoulder, and lower back complaints affect roughly half of people who sit at a computer for long stretches. Strengthening the rear delts helps pull the shoulders back into a more neutral position and can ease some of that daily tension.

Injury prevention. If your front delts and chest are strong but your rear delts are weak, your shoulder joint sits in an imbalanced position. Over time, this kind of imbalance is linked to shoulder impingement and rotator cuff issues. Balanced shoulder training helps protect the joint from wear and tear.

Aesthetics. Rear delts are what give shoulders that “3D,” capped look from the side and back, not just from the front. Without them, shoulders can look flat or unfinished, even if the front delts are well developed.

Performance. Strong rear delts support your bench press by stabilizing your shoulder blades, help you row and pull with more control, and improve your overhead pressing mechanics. They’re a small muscle group with a surprisingly large role in upper body strength.

Signs Your Rear Delts Are Undertrained

Before jumping into exercises, it helps to know if this even applies to you. Common signs include:

• Your shoulders round forward when you stand relaxed
• Your front delts get sore easily, but your rear delts almost never do
• Your shoulders look flat or narrow from a side profile
• You feel weak or unstable during rows and pulling movements
• You spend most of your day sitting at a desk or looking at a phone

If two or more of these sound like you, it’s worth adding direct rear delt work to your routine.

The Best Rear Delt Exercises

Here are the most effective exercises for building and strengthening your rear delts, based on both practical coaching experience and muscle activation research.

1. Face Pulls

Using a cable machine with a rope attachment, pull the rope toward your face while flaring your elbows out wide and squeezing your shoulder blades together.

This is often called the most underrated shoulder exercise, and for good reason. It hits the rear delts, the rotator cuff, and your upper back all at once, making it one of the best exercises for both muscle growth and posture correction.

2. Reverse Pec Deck Fly

Sit facing into a pec deck machine, grab the handles, and pull your arms backward in a wide arc, squeezing your shoulder blades at the end.

Research comparing different shoulder exercises has consistently found that the reverse pec deck produces some of the highest posterior deltoid activation of any exercise tested, even more than several rowing movements. If your gym has this machine, it deserves a regular spot in your routine.

3. Bent-Over Dumbbell Reverse Fly

Hinge at the hips with a slight bend in your knees, let the dumbbells hang below your chest, then raise your arms out to the sides in a wide arc.

This is a classic for a reason: it’s simple, requires minimal equipment, and directly targets the rear delts when done with control rather than momentum.

4. Cable Rear Delt Fly (Cross-Body)

Set two cables at chest height, cross the handles, and pull them apart and slightly back, one arm crossing over the other at the start.

Cables keep constant tension on the muscle throughout the entire movement, unlike dumbbells, which lose tension at certain points. This makes cross-body cable flys excellent for building rear delt size over time.

5. Chest-Supported Reverse Fly

Lie face-down on an incline bench set to about 30 to 45 degrees, holding dumbbells, and raise your arms out to the sides.

Because your chest is supported, it’s almost impossible to cheat with your lower back or momentum. This makes it one of the best options if you struggle to feel your rear delts working during standing versions.

6. Band Pull-Aparts

Hold a resistance band with both hands in front of you, arms straight, and pull it apart until it touches your chest.

This is a fantastic warm-up move, a great finisher, and an easy option for home workouts since all you need is a light resistance band. It’s low-impact enough to do daily without overtraining the joint.

7. Single-Arm Cable Reverse Fly

Standing side-on to a cable machine, pull the handle across your body and back with one arm, focusing on squeezing the rear delt at the end range.

Training one side at a time helps you correct strength imbalances between your left and right shoulder, which is common if you favor one arm during daily activities.

8. Incline Y-Raises

Lying face-down on an incline bench, raise your arms up and slightly out to form a “Y” shape, thumbs pointing toward the ceiling.

This one is genuinely underrated. It targets the rear delts along with the lower traps, muscles that are often just as neglected and just as important for shoulder health and posture.

9. Wide-Grip Rear Delt Row

Using a barbell, dumbbells, or a cable, row the weight toward your upper chest or chin with a wide grip and flared elbows.

Compared to a standard row, the wide grip and high elbow position shift more of the workload onto the rear delts instead of the lats, making this a solid hybrid movement.

10. Prone Reverse Fly on the Floor

Lying face-down on the floor or a mat, raise your arms out to the sides just a few inches, holding light weights or none at all.

This is a great option if you’re new to rear delt training or working around a shoulder issue, since gravity and the floor naturally limit how far you can go, reducing the risk of cheating the movement.

The Exercises Most People Skip Entirely

If I had to point to the exercises that lifters overlook the most, it would be the Y-raise, the chest-supported reverse fly, and band pull-aparts. These three don’t feel as “heavy” or impressive as a barbell row, so they often get left out of programs entirely. But they’re some of the most effective tools for improving both posture and shoulder shape, precisely because they isolate the rear delt without other muscles taking over.

How to Program Rear Delt Training

Because rear delts are a smaller muscle group and respond well to frequent light work, here’s a simple framework:

• Frequency: 2 to 3 sessions per week
• Volume: 3 to 5 sets total per session across one or two exercises
• Rep range: 12 to 20 reps, since rear delts tend to respond well to higher reps and shorter rest
• Placement: After pressing or pulling exercises, or as part of a dedicated shoulder day

Sample Rear Delt Workout

1. Face pulls – 3 sets of 15 reps
2. Reverse pec deck fly – 3 sets of 12 reps
3. Incline Y-raises – 2 sets of 15 reps
4. Band pull-aparts – 2 sets of 20 reps (as a finisher)

Common Mistakes to Avoid

• Using too much weight. This turns the movement into a row and shifts the work onto your back instead of your rear delts.
• Using momentum. Swinging the weight up rather than lifting it with control reduces muscle activation significantly.
• Shrugging your traps. Keep your shoulders down and away from your ears throughout the movement.
• Cutting the range of motion short. Full range, especially the stretch position, is where a lot of the growth stimulus comes from.
• Never changing exercises. Rotating between machines, cables, and dumbbells over time keeps progress moving and prevents plateaus.

A Quick Story From the Gym Floor

One of my long-term clients came to me frustrated that her shoulders “wouldn’t grow,” despite months of consistent pressing work. Her posture was noticeably rounded from sitting at a desk all day. We added face pulls, band pull-aparts, and chest-supported reverse flys three times a week, nothing fancy. Within about six weeks, not only did her shoulders start to look fuller from the side, but she also mentioned that the tightness she used to feel between her shoulder blades by the end of the workday had mostly disappeared. That’s the rear delt effect in action: it’s rarely dramatic, but it adds up.

Frequently Asked Questions

How often should I train rear delts? Two to three times per week works well for most people, since it’s a smaller muscle group that recovers relatively quickly.

Can I train rear delts every day? Light work, like band pull-aparts, can be done daily. Heavier, more demanding exercises like reverse pec deck flys are better limited to two or three sessions a week to allow recovery.

What’s the best rear delt exercise for building size? The reverse pec deck fly and cable reverse fly tend to produce the highest muscle activation, making them strong choices if hypertrophy is your main goal.

Do rear delts need heavy weight or high reps? Higher reps with lighter to moderate weight and strict form usually work better for this muscle group than going heavy, since heavy loads make it easy to cheat with momentum.

Can rear delt training fix rounded shoulders? It helps significantly, especially when combined with stretching the chest and strengthening the upper back, but it works best as part of a full posture routine rather than a standalone fix.

What’s the difference between rear delts and traps or rhomboids? Rear delts sit at the back of the shoulder joint and move the arm, while traps and rhomboids sit on the upper back and control the shoulder blades. They work together, which is why exercises like face pulls and Y-raises train both at once.

Final Thoughts

Rear delts might be small, but skipping them shows up in the mirror, in your posture, and eventually in how your shoulders feel day to day. You don’t need to overhaul your entire program to fix this. Pick two or three exercises from this list, like face pulls, reverse pec deck flys, or Y-raises, and add them into your next couple of workouts.

Give it four to six weeks of consistent effort, and you’ll likely notice the difference before anyone else does, standing a little straighter, moving a little more freely, and finally getting that complete, three-dimensional shoulder look you’ve been training for.