How to Do the Bent Over Rear Delt Fly (Form & Benefits)

Strength training can be beneficial for your muscles, bones, and overall health, and exercising each muscle group equally can help keep your body balanced.

That means training the smaller, more often neglected muscles like the rear deltoids.

The bent over rear delt fly may not be an isolation exercise, but it does target the harder to reach rear delts, as well as a few of the major muscles in your upper back. It may not be as fun as the  bench press or bent over row, but it can help make these bigger lifts even stronger.

Why are the Rear Delts Important?

The rear delts, commonly referred to as the posterior deltoids, are one of three heads of the deltoid muscle, which is the largest muscle in your shoulder. Along with the anterior deltoids and lateral deltoids, these muscles work to abduct, extend, and flex your arm, as well as help provide stability to the shoulder joint.

As the name suggests, they are located on the rear side of your shoulder and connect to the scapular, which are the muscles surrounding the shoulder blades.

The primary responsibility of the rear delts is to extend your arm backwards, but they also play a role in pulling your shoulders back to create better posture and reduce your risk of injury.

Often lifters may focus on the anterior or front delts because those are the muscles you can see in the mirror, but neglecting the rear delts can lead to muscle imbalances.

Not exercising your shoulder muscles equally can lead to a shoulder injury, which accounts for over a third of sports-related injuries.

Even if you don’t experience an injury, weak rear delts can cause pain in your back and shoulders and instability of the shoulder joint.

While the arm is abducted, the rear delts help to stabilize the shoulder, so strengthening them can help you throw, lift, and function better.

Benefits of the Bent Over Rear Delt Fly

Training your shoulders doesn’t just mean you can lift heavier, but it also means you can stand up straight better, experience less pain, and build a more toned upper body.

Better Posture

If your rear delts are weak, it can cause your shoulders to hunch forward, resulting in poor posture.

The bent over rear deltoids recruits not only the rear delts, but the rhomboids and trapezius too, both of which can contribute to better posture.

The rhomboids are located on your upper back along your spine, and they help to pull your shoulder blades together. The traps are located in your upper and mid back, and they help pull your shoulder blades back and down. Training all of these muscles together can help contribute to improved posture.

Reduced Back Pain

Back pain is a common issue and is one of the main reasons for seeking emergency care.

Muscles like the traps and rhomboids help to support the back, and if these muscles are weak, it can cause poor posture and pressure on your spine. Keeping your back muscles strong with the rear delt fly can help reduce pain in your mid and upper back.

Upper Body Strength

Exercising only the bigger muscles or the muscles you see in the mirror could lead to strength and muscle imbalances. Training the smaller muscles can help make those bigger lifts even better. Performing exercises like the rear delt fly can help strengthen some of the muscles that contribute to stronger, more stable lifts. Different row variations or cleans are big compound exercises, but they can be improved by strengthening the rear delts.

Better Shoulder Stability

An exercise like the lateral raise relies on the rear delts for stability when the arm is abducted. When the shoulder muscles are weak, it can cause instability of the joint and put you at a greater risk of pain or injury. Improving your shoulder stability can help improve other areas of your life, whether that means heavier lifts or just a better quality of life. Anytime you move your arm or lift anything overhead, you rely on shoulder stability.

Shoulder Hypertrophy

Building muscle doesn’t just happen with bench presses and deadlifts. Big compound lifts are great, but the smaller lifts like the rear delt fly can target specific muscle groups better, which is beneficial for muscle growth. Although not an isolation exercise, the rear delt fly is beneficial for building the posterior deltoids and helping to build a well-rounded, balanced looking shoulder. This can be a good exercise for bodybuilding or used as an accessory or warm-up exercise for powerlifting.

How to Do the Bent Over Rear Delt Fly

Proper form is crucial when weightlifting, and the rear delt fly is one of those exercises that is often performed improperly. The hip hinge can be difficult for lifters, especially beginners, to master, and knowing how to properly engage your back muscles, so you’re not hunching, can take time and practice.

Check out our exercise guide to get you started:

1. Stand with your feet about hip-width apart, a slight bend in your knees, and one light to moderate weight dumbbell in each hand.
2. Roll your shoulders down and back and keep a slight pinch in your shoulder blades.
3. Maintain this neutral spine position as you push your hips back. This hip hinge can be difficult to get down at first, so using a mirror or a personal trainer can help.
4. Once your back is just about parallel with the floor, extend your arms toward the ground and hold the dumbbells with a neutral grip. Make sure to engage your core to help avoid your lower back from arching.
5. With a slight bend in your elbows, open your arms up towards the ceiling by squeezing your shoulder blades together.
6. When you’ve reached a full range of motion, slowly lower your arms back to the starting position and breathe before starting your next rep.

Bent Over Rear Delt Fly Variations

Although the rear delts can be difficult to target, the rear delt fly isn’t the only exercise that works them.

Check out some of the different variations you can try and still recruit the same muscle groups:

Band Pull-Aparts

Using a resistance band is a great way to simulate the resistance of dumbbells and can contribute to  strength and muscle gains.

The band pull-apart uses the same movement as the rear delt fly but without the hip hinge. If your hip hinge needs work, this exercise can help strengthen the same muscle groups and is also a great warm-up exercise for other shoulder exercises.

How to do Band Pull-Aparts: 

1. Hold a resistance band in both hands at chest height with your arms extended in front of you.
2. Keep your arms straight as you pull the band apart and squeeze your shoulder blades.
3. Slowly return to the starting position.

Incline Reverse Flyes

Similar to the rear delt fly, the incline reverse fly has you lie on an inclined bench and perform the fly motion. This can be a beneficial variation for a couple different reasons. The first being it eliminates the need for the hip hinge or the stabilization of the core, and the second being it doesn’t allow you to use momentum, helping to ensure your muscles and not the momentum are doing the work.

How to do Incline Reverse Flyes: 

1. Set a bench to an incline about 45 degrees. 
2. Lie face down with your chest supported by the bench and hold one dumbbell in each hand.
3. Squeeze your shoulder blades together as you raise your arms up.
4. Slowly lower the weights when you've reached your full range of motion.

Rear Delt Raise

The rear delt raise might look the same as the rear delt fly, but the delt raise is performed with your arms straight. It’s similar to a lateral raise, but you are slightly hinged over to help get better rear delt activation. This variation also targets the traps and the rhomboids and can be beneficial for building shoulder and upper back muscle.

How to do the Rear Delt Raise: 

1. Hold one light dumbbell in each hand. 
2. Slightly hinge over at your hips but not as much as you would the rear delt fly. 
3. Keep your arms straight as you raise your arms up similar to a lateral raise. 
4. Lower back to the starting position.

Single Arm Cable Rear Delt Fly

A cable machine is extremely versatile and uses a pulley system attached to weights for resistance. The single arm rear delt cable fly uses the same movement pattern as the rear delt fly, but with no hip hinge.

Unlike a dumbbell or barbell, the cable machine can help you keep constant tension on the muscle as long as the weight plates aren’t touching each other. Increasing the time under tension can help build muscle and strength.

How to do the Single Arm Cable Rear Delt Fly: 

1. Stand next to the cable machine loaded with the appropriate amount of weight for your fitness level.
2. The cable should be secured at shoulder height.
3. Keep your arm straight as you pull the cable back by squeezing your shoulder blades. 
4. Return to the starting position and repeat on the other side. 

Build More Balanced Shoulders

Although we may gravitate towards the exercises that build the big muscles we can see, the smaller muscles can make us stronger and more sculpted. The rear delts are a neglected muscle, but they are so important to maintaining a balanced set of shoulders.

If you’re wanting bigger and better lifts, you can’t forget about the smaller lifts because it’s not just the pecs and the lats that do all the upper body work.

Exercises like the rear delt fly and a pre-workout like  Charged-AF can enhance your performance in the gym, and stronger, more stable shoulders can enhance your quality of life.