Trying to get those 3D shoulders that your favorite fitness influencer has? If so, you really need to start focusing on your rear delts. One option is the rear delt cable fly.

This exercise is my personal favorite and go-to exercise when it comes to training your rear delts.

Apart from making your shoulders look bigger, rear delts help in many pulling movements and help stabilize the shoulder joint. In fact, a lot of the back exercises you do train your rear delts to a large degree. However, you need to start including isolation exercises into your workout routine like the rear delt cable fly.

And, speaking from personal experience, the rear delt cable fly is by far the most effective way to isolate your rear delts, if done with proper form.

So, what is the proper form? What are some variations or alternative exercises? What are the benefits of this exercise compared to others?

Don’t worry. We’ve got you covered. But before we get into the exercise itself, let’s start with the importance of our rear delts.

Rear Delts 101

Yes, here comes the theory lesson. Rear delts, or posterior delts, are one of the three deltoids located in the back part of our shoulder. More specifically, rear delts are located on the spine of your shoulder and attaches your humerus which is the upper arm bone. The other two deltoids are the front delts, or the anterior delts, and the lateral delts.

So, what’s the function of our rear delts? Why should we train them? Well, as we mentioned before, rear delts help in many pulling movements and stabilizes our shoulder joint. Apart from this, training our rear delts can reduce many shoulder related injuries.

The function of our rear delts is to move our arm backwards. Ultimately, it helps with shoulder horizontal abduction and external rotation. Hence the exercises we perform to target this muscle group will involve moving our arm back.

You might not want to accept this, but a lot of us have highly underdeveloped rear delts simply because they tend to be ignored and never trained. And you might argue that rear delts are used in many back movements, however rear delt isolation exercises have far more rear delt involvement.

And let’s not forget that we all want those 3D shoulders.

How to Perform the Rear Delt Cable Fly?

Like any exercise, you need proper form and technique to get the most out of it. And I’ll be honest, the rear delt cable fly is straightforward and simple, however there are those small errors that we don’t even notice which can really restrict our gains!

Here is how you perform the rear delt cable fly correctly.

The Set-up:

1. Set your cables at about head height or slightly higher.
2. Stand upright with your feet about shoulder width apart.
3. Grab the LEFT CABLE with your RIGHT HAND and grab the RIGHT CABLE with your LEFT HAND. I like to use the rubber ball attached at the end of the cable, however you might want to use a single hand attachment if that’s more comfortable.
4. Step back and pull the cables so that your arms are straight out in front of you. Have your elbows slightly bent. Make sure you retract your shoulder blades. This is your starting position.

The Motion

1. Keep your core tight and open your arms and bring them back and out. Your arms must be straight with only a slight bend at the elbows. Also, perform this motion with your arms relatively in the same position.  
2. As you reach peak contraction, squeeze your rear delts.
3. SLOWLY return your arm back to the starting position. Again, your arms should only have a SLIGHT bend at the elbows.
4. Repeat for the desired number of reps.

Related Reading: Best Legs and Shoulder Workout

Sets and Reps for the Cable Rear Delt Fly

To get the best results, aim for 3-4 sets of 8-12 repetitions. Personally, I do 4 sets of 8-12 repetitions with some other rear delt exercises (that I have mentioned later on in this article) to get the best results.

Muscles worked

Well, it’s in the name. REAR DELT cable fly’s work the rear delts. However, they do work some other muscles as well including the traps and rhomboids.

Yes, it’s still an isolation movement primarily working the rear delts however it does have secondary muscles that are involved.

Common Mistakes and Pro Tips

Yes, I know. You might be wondering what’s so hard about this exercise, right? It may not look hard, but there are still mistakes that are made which will negatively affect your gains.

1. Going Too Heavy!

Like any exercise, you need to perform the rear delt cable fly with proper form and technique to get the most out of it.  Going too heavy will result in poor form, half reps, and risks injury. Instead starting off with lighter weights and focusing on your form and gradually increasing your weights is the best way to go. This applies for most exercises.

If you’ve been reading Just Fit & Healthy articles, you should know that we do NOT support ego lifting. So, stop comparing yourself with people around you and decrease that weight and perform this exercise properly.

2. Exercise Speed

The biggest and most common mistake people make is finishing their exercise set too quickly. If you want to develop that mind muscle connection and get the most out of the exercise, you really need to start slowing down your reps. The slower you go, the more tension you place your working muscles under. In this case your rear delts.

In fact, a study was done comparing slow speed resistance training and regular speed resistance training. The slow speed resistance training resulted in a 50% greater increase in strength compared to regular speed.

The speed of your reps matters more if you’re performing isolation exercises like the cable rear delt fly.

3. Bending your Elbows.

If you want the most tension being placed on your rear delts, you need to make sure that your elbows are only SLIGHTLY bent. Bending your elbows too much removes the tension on your rear delts and places it on other muscles like your triceps. This generally happens when you increase the weight too much.

Instead, pick a weight that you can do with proper form and one that challenges your rear delts.

You might also start to bend your elbows when you reach the end of your set. If this happens and you literally cannot perform the last few reps without bending your elbow, decrease the weight and complete your set.

4. Arm Positioning Throughout the Exercise

When you’re opening your arms, make sure that your arms are in line with your shoulders. Going slightly lower is fine as well but if your arms are going too low, your lats will start getting involved. Now, although this isn’t a bad thing, there are just so many other exercises you could do for your lats, and this isn’t one of them.

We are trying to focus on the rear delts so make sure you have only a slight bend in your elbows and your arms are relatively in the same position throughout the entire movement.

5. Squeeze at the End

I can’t stress this enough. When you reach the end of the movement, pause and squeeze to get the most rear delt activation. And it’s not just the rear delt fly, pretty much all weight training exercises require that pause and squeeze at the end. Ultimately, you’re putting your targeted muscle in maximum tension.

Most people reach the end of the movement and instantly come back to the starting position. I want you guys to pause and squeeze your rear delts to get that mind muscle connection, and you will start noticing greater improvements.

Variations and Alternatives

I understand. Doing the same exercise over and over again can be boring and it’s always good to add some variety to your workouts. Here are some of the best rear delt cable fly alternatives and variations.

1. Dumbbell Reverse Fly

Let’s start with a question. What is the hardest part of the rear delt cable fly? Thought of an answer? That’s right. The hardest part about this exercise is finding an available cable machine. I don’t know about you guys but for me, no cable machine is ever free. That’s where the dumbbell reverse fly comes in handy.

Steps:

1. Grab a pair of dumbbells so that your palms are facing each other and stand upright.
2. Hinge at the hips until your upper body is nearly parallel to the floor. The dumbbells should be hanging in straight down.
3. Ensure your back is straight. Open your arms and raise the dumbbells to your sides until they are in line with your shoulders. Have a slight bend in your shoulders
4. Perform this for the desired number of reps.

This is a really good alternative to the cable rear delt fly. But remember, the further you drive your elbows back, the more rear delt activation you will get. Of course, you don’t want to end up doing the same rear delt cable fly again and again in the gym. Maybe use this at the gym. This exercise can also be down with cables.

2. Single arm Cable Rear Delt Fly

This is an obvious variation to the standard cable rear delt fly. Just perform this one arm at a time. Why would you want to do this? Well, the benefit of unilateral training is that the tension is applied to both arms equivalently instead of the dominant arm doing most of the work.

Another similar variation is instead of driving your arm across almost in line with your shoulder, drive the arm at a 45-degree angle from your torso.  Now I know I previously said that if your arms drop, it takes tension off the rear delts and activates the lats. However, instead of stopping the motion when the arm aligns with your body, keep driving that arm back behind you.

With this, you will notice a greater tension on the rear delts.

3. Face Pulls

Before we start with this alternative, let me ask you a question. What are the main functions of the rear delts? Hint: I explained this earlier.

That’s right. It’s shoulder horizontal abduction and external rotation. For the external rotation, we have the face pulls.

How do you perform this?

1. Set up a cable machine and have the pulley positioned above your head. Use a double rope attachment.
2. Grasp the rope with both of your hands and make sure that your palms are facing in.
3. Step back and lean back slightly. Make sure your arms are fully extended.
4. Pull the rope towards your face with your elbows flared out. Keep pulling until your arms can’t go further back and your palms are on either side of your face.
5. Return to the starting position.

If you want to really isolate your rear delts with this movement, try performing this lying down. This way other working muscles like the upper traps aren’t activated.

4. Wide Grip Seated Cable Row

As we mentioned previously, the main function of the rear delts is to move our arms backwards. This can be easily achieved with the wide grip seated cable row. Why not a short grip or a neutral grip? Well, with the wide grip, you will notice that your elbow travels much further back and hence will give the best rear delt activation.

However, this is a compound movement so definitely give this one a try, but also include isolation exercises for the rear delts like the rear delt cable fly.

Healthline has done a brilliant job in giving us the best rear delt exercises to try.

This also raises a question. Rear delts are part of your shoulders however they are used a lot during your back day. So, should you train your rear delts during your back workout or shoulder workout?

Should You Train Your Rear Delts During Back Day or Shoulder Day?

What I would recommend is distributing rear delt exercises throughout both your shoulder and back day. Maybe perform rear delt cable fly and dumbbell reverse fly during your shoulder day. During your back day, try incorporating wide grip seated cable rows and face pulls.

Also make sure that you’ve separated your back and shoulder day by at least 48 hours. That way your rear delts will have enough time to recover.

Key Takeaway

Rear delts are extremely important, especially if you want those 3D shoulders. They also help with many pulling and movement and they help stabilize our shoulders. Unfortunately, they are often neglected. An easy way to target your rear delts is with the rear delt cable fly.

Hopefully this article has given you all the information you need about the rear delt cable fly and some good alternatives and variations to try out. Stay tuned for our upcoming articles and as always, stay Fit & Healthy!