Why You Should Work Your Rear Delts

What are rear delts, and are they important to work out? Dr. Jonathan Su, the Get-Fit Guy, explains why giving these important shoulder muscles a little love can help you improve posture, reduce injuries, boost performance, and look great in a tank top.

Dr. Jonathan Su, DPT, CSCS, TSAC-F, C-IAYT
5-minute read
Episode #568
The Quick And Dirty
  • Your deltoids are made up of three distinct parts (front, mid, and rear).
  • Strong rear delts can help you improve posture, reduce injuries, boost performance, and look great.
  • Strengthen your rear delts by performing the following exercises: reverse fly, external rotation, and rows.
  • Continue reading for an in-depth look at these muscles.

It’s not every day that you hear someone say “it’s rear delts day at the gym!” You typically hear people say “it’s shoulder day” and you see popular exercises such as the overhead press, front or lateral raises, and upright rows being performed.

Don’t get me wrong, these are all great shoulder exercises for strengthening your deltoids—“delts” for short—the large triangular-shaped muscles that give your shoulders their rounded contour. I know because I use all of these exercises as part of my workout routine!

The problem is that none of these exercises actually target your rear delts. Rear delts you ask? Yes, the all-important rear delts that our high school PE teacher conveniently never taught us about.

Our delts are made up of three distinct parts (front, mid, and rear) and all the previously mentioned shoulder exercises target either the front or mid delts. The rear delts are frequently ignored or forgotten about. 

That’s a problem because giving the rear delts a little love and attention can help you improve posture, reduce the risk of injuries, and boost athletic performance. Let’s also not forget that strong rear delts also look great in a tank top.   

Shoulder anatomy made simple

One of the main muscles that moves your shoulder is your deltoid. The word “deltoid” comes from the Greek letter “delta” which is shaped like a triangle. Your deltoids are named as such because they look like an upside-down triangle. Actually, they’re shaped more like a half cone, but close enough. 

This muscle wraps from your collar bone to the spine of your shoulder blade on top and converges on the side of your upper arm or humerus about a third of the way down. As mentioned earlier, your deltoids are made up of three distinct parts (front, mid, and rear). 

Your front, mid, and rear delts primarily work to lift your arms forward, sideways, and backward, respectively. Your front delts also rotate your arms inward while your rear delts rotate your arms outward. 

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Importance of working your rear delts

I can’t emphasize enough the importance of working your rear delts. If you’ve neglected these muscles for most of your life as most people have, when you start working them, it’ll be like taking your first sip of warm coffee or hot cocoa after getting stuck in a blizzard for 24 hours without any power. 

Your body reacts in a way that just lets you know that you’re doing something right. If you’re still not convinced that working on your rear delts should be a priority, here are 4 reasons that’ll hopefully persuade you to start hitting up these muscles this week.

1. Improves your posture

Many of us spend a good part of our day sitting in front of a computer, tablet, or phone with our shoulders hunched forward. Like cement drying, we risk making this position a fixture of our posture over time. 

Your rear delts work alongside your rhomboids and mid trap muscles on the backside of your body to pull your shoulders back. This is important for good posture because it prevents your shoulders from hunching forward to keep your body in an upright position. 

2. Reduces injuries

Your front and mid delts tend to be dominant in a lot of exercises which creates an imbalance in your shoulders. This imbalance leads to excessive stress in your shoulders and increases the risk of injuries. 

Imagine driving your car for thousands of miles with your rear tires only half-inflated. Not only do you get poor mileage but you also increase the wear-and-tear on your tires. This is similar to what your body goes through when your rear delts are weak in relation to your front and mid delts. 

3. Boosts performance

When your front, mid, and rear delts are balanced and working together, it’s like having all of the cylinders of your engine firing in harmony. The result is improved performance in everyday activities and athletic performance. 

That’s because these muscles all work together to keep your shoulders stable, which translates into improved quality of movement. Improved quality of movement is like having improved handling on your car from power steering and traction control.

4. Looks great

Working your rear delts will help you fully develop your shoulders, which will, in turn, lead to amazing looking shoulders. I’m not going to lie, one of the reasons why I spend time working my rear delts is to look better and there’s no shame in that. 

How to work your rear delts

Here are 3 of my favorite exercises for working the rear delts. Perform 3 sets of 15 reps for each exercise on non-consecutive days. Check out my YouTube channel for videos on how to perform each exercise. 

Reverse fly 

Lie face down on a bench with a dumbbell in each hand and the inner sides of your hands touching each other. Begin exercising by moving your hands away from each other until your arms are parallel to your torso. Return to the starting position and repeat for up to 15 repetitions. 

External rotation

Lie on your side with a dumbbell in your top hand. Tuck your top elbow against the side of your body with your elbow bent 90 degrees and your hand against your belly button. 

Begin exercising by rotating your top hand away from your belly button as far as you can comfortably go while keeping your elbow against the side of your body with your elbow bent 90 degrees. Return to the starting position and repeat for up to 15 repetitions. 


Place your same side knee and hand on a flat bench with your back parallel to the floor. Hold a dumbbell in your opposite hand with the hand hanging toward the floor and the same side foot on the floor. Begin exercising by pulling the dumbbell toward the side of your body. Return to the starting position and repeat for up to 15 repetitions. 

5-day rear delt exercise challenge

Let’s put this knowledge to use with a 5-day rear delt exercise challenge! Over the next five days, your challenge is to exercise your rear delts for 2 or 3 days on non-consecutive days. Give it a try and let me know how you feel by emailing me at getfitguy@quickanddirtytips.com or leaving me a voicemail at 510-353-3104. 

All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Dr. Jonathan Su, DPT, CSCS, TSAC-F, C-IAYT

Dr. Jonathan Su is the host of the Get-Fit Guy podcast. He is a physical therapist and fitness expert whose mission is to make fitness accessible for everyone. Dr. Su is author of the bestsellers Six-Minute Fitness at 60+ and Six-Minute Core Strength.

Got a question for Dr. Su? You can email him at getfitguy@quickanddirtytips.com or leave him a message at the Get-Fit Guy voicemail line at (510) 353-3104.