Written by Steve Theunissen | ISSA: CPT & Fitness Nutrition
Fact checked by Tyler DiGiovanni, BSBM
FACT CHECKED
The posterior, or rear, delts don't seem to get much love among gymgoers. They're often trained as an afterthought, with a few sets of rear delt raises thrown in at the end of a grueling shoulder pressing and side raise session to hit the more showy front and side delts.
Yet, you will never get a truly impressive upper body unless you give the rear delts the attention they deserve. This muscle completes the rounded cap of your delts and ties into your traps and lats. Guys who ignore it look much narrower and thinner than the ones who do it justice.
But to grow impressive rear delts, you must do the right exercises the right way. In this article, I'll lay out the three best exercises (spoiler: Rear delt cable fly, lying supine cable crossover, and bent over one arm cable rear delt raise) for the rear delts, explaining the physics of why they're all you need and putting them together into a workout that works.
The Best Rear Delt Exercise: Rear Delt Cable Fly
The best rear delt exercise will have you holding resistance in each hand with your hands together in front of your scapula. You then move your arms down and back in an upside-down 'V' motion, ending with your hands out to the sides of your waist.
The best exercise to do that is the cable rear delt fly.
You will need a double pulley machine to perform the rear delt cable fly. If you only have access to a single pulley machine, you can do the exercise on it one side at a time.
Step-by-Step
- Set the pulleys on a double pulley cable machine to their highest setting. Remove the handles from the ends of the cables.
- Stand facing the machine about three feet in front of it and grab the ends of the cable crossover so your right hand is holding the left cable and vice versa.
- In the starting position, your hands should be crossed over at the level of your sternum.
- Extend your arms down and slightly back in an upside-down 'V' motion until fully extended to the sides of your waist.
- Contract your rear delts in this position.
- Return to the start position under control. Do not bring your hands higher than your sternum.
It should be noted that the rear deltoids are a relatively small muscle. As a result, it doesn't need a lot of weight to be maximally stimulated. I recommend using just a single plate on the pin weight stack for your first set and adjusting from there. I use fractional plates that can be added to the weight stack to get the right weight for the number of reps I'm doing.
The Second Best Rear Delt Exercise: Lying Supine Cable Crossover
The lying supine cable crossover is similar to the previous exercise, except it involves lying on a bench placed in the middle of the cable crossover machine. This makes for a stricter exercise, as you cannot use back-swing to introduce momentum to the movement. It also reduces strain on the lower back. This might be a tough exercise to pull off in a crowded gym, so I've also provided some alternate exercises further down in the article.
Step-by-Step
- Place a flat bench in the center of the cable crossover machine. Set the pulleys at your shoulder level when standing.
- Grab the opposite cable handles and lie on the bench.
- In the starting position, your arms should be extended directly above your chest with your hands together.
- Bring your arms down and out without bending your elbows.
- In the bottom position, your hands should be in line with your ribcage.
- Return to the start position under control.
The Third Best Rear Delt Exercise: Bent Over One Arm Cable Rear Delt Raise
The bent-over-one-arm cable rear delt raise allows you to focus on each side of the rear delts. Even though the action is opposite to the previous two exercises, with the arm coming up diagonally, it still follows the ideal angle of resistance because the cable pulley is set low.
Step-by-Step
- Set the pulley on a cable pulley machine to its lowest position.
- Stand side-on to the machine, about a foot away from it.
- Bend over so your torso is parallel to the floor.
- Grab the cable with your outside arm.
- In the start position, your outside arm should be reaching across so that it is just in front of your opposite shin.
- Pivot from the shoulder joint to extend your arm back and slightly outward in a diagonal action.
- Lower under control and repeat.
Rear Delt Anatomy
The rear delt muscle originates on the upper ridge of the scapula and inserts at the top of the upper arm (humerus), right behind the insertion of the lateral delts. The muscle's main job is to pull the upper arm back and down. It also assists in the external rotation of the upper arm.
The rear delt muscle fibers run diagonally from the origin to the insertion point. The ideal exercise for this muscle will simulate this muscle fiber direction. That direction causes the upper arm to move down and back when you are in a standing position. In the top position, your hands would be together at sternum level; in the bottom position, they would be extended to your sides at waist level. The arm movement would be down and slightly back.
That is not what you see with most conventional rear delt exercises. Instead, they emphasize having the arms either coming up from a low position, as in the rear delt raise, or perpendicular to the body, as on the rear delt machine. Those movements do not allow you to perform the natural action of the rear delts through its full range of motion, which is to extend the upper arms down and back in a diagonal sweeping motion.
Why The Cable Pulley is Best for Rear Delts
We have established that the best exercises to target the rear delts will involve a direction of resistance that aligns with the direction of movement of the muscle in its natural function. It should also align with the direction of the muscle fibers. In each case, that direction is diagonally down.
When you use a free weight, such as a dumbbell or a barbell, the direction of resistance is only ever straight down, in accordance with gravity. So, there is no way you can effectively work your rear delts with free weights.
When you use a cable pulley machine, however, you are able to set the direction of cable resistance. By setting the pulleys at their highest position and then grabbing the opposite cable ends so that your left hand is grabbing the right cable and your right hand is holding the left cable, you are able to create resistance through the ideal downward diagonal range of motion.
We love the cable machine for rear delts so much that we dedicated an entire article to the Best Cable Rear Delt Exercises.
Rear Deltoid Workout
I recommend working your posterior deltoids along with your front and side delts. Each of these three segments of your deltoid is a relatively small muscle, so they do not require a huge volume of work. I have found that around six sets for each head is ideal, giving you a total of 18 sets for your shoulders.
As we have identified, the rear delt cable fly is the single best exercise to work your rear delts. As a result, this exercise should be done for all six sets.
The rear delts respond best to higher reps. I have been using the following rep scheme with my bodybuilding personal training clients for decades with great results:
Each time you decrease the reps, you should slightly increase the resistance. Make use of fractional plates if your gym has them.
The other two cable exercises are not as good as the rear delt cable fly because they do not allow for as natural a range of motion. However, they are useful if you want to inject some variety into your workout. I recommend throwing one or the other in every fourth workout.
What if you Don't Have a Cable Machine?
So far, I've laid out the three best rear delt exercises in terms of muscle hypertrophy and strength development. But what if you don't have access to a cable pulley machine? Maybe you're working out in your home gym and need to do dumbbell rear delt exercises. Or it could be that your gym doesn't have a double pulley machine. Perhaps it's got one, but the time you visit the gym, it's almost impossible to find it available.
The following exercises are not as good as the three cable moves in the last section. However, they will still work your rear delts, just not as effectively. They make good alternatives for people who do not have access to a cable pulley machine.
Reverse Pec Deck Machine
The reverse pec deck machine moves your arms perpendicularly to your torso, which, as we have seen, is not the ideal direction of movement to hit the rear delts. However, it does activate the rear deltoid through the top half of its range of motion. Also, the fact that you are seated takes all the pressure off your lower back.
Step-by-Step
- Set the seat height so that your arms are moving horizontally.
- Sit on the reverse pec dec machine facing into it, and grab the handles.
- Push back with your delts to move handles together and contract your shoulder blades.
- Slowly return and repeat.
Incline Rear Delt Raises
The incline rear delt raise starts low and ends high and, because it uses dumbbells, has a direction of straight down resistance. This means you're fighting gravity as well as the weight.
Step-by-Step
- Set an incline bench to a 45-degree angle.
- Grab a pair of dumbbells and lie face down on the bench so your arms are hanging over the edge with your palms facing each other. Plant your feet firmly on the floor and press your lower back into the spine.
- With your elbows slightly bent, pivot from the shoulder joint to bring your arms back and out.
- Pause for a moment in the top position as you squeeze the posterior deltoid head.
- Lower under control and repeat.
Bent Over Rear Delt Raise
The bent-over rear delt raise is similar to the previous exercise, with the difference that it doesn't provide the same level of protection for your lower back. Nor does it ensure that you can't use momentum to lift the weight.
However, the bent-over rear delt raise is probably the most convenient posterior deltoid exercise. All you have to do is grab a pair of dumbbells and start repping out.
Step-by-Step
- Grab a pair of dumbbells and stand with your feet shoulder-width apart.
- Bend at the hips so your torso is parallel to the floor.
- Hang your arms in front of you with your palms facing each other. Your elbows should be slightly bent but locked in position.
- Pivot from the shoulder joint to bring your arms back and out (rather than directly up to shoulder level).
- Lower under control and repeat.
Lying One-Arm Delt Raise
The lying one-arm delt raise does a good job of isolating each side of the rear deltoid muscle. This is also a strict movement that prevents momentum.
Step-by-Step
- Lie on a bench on your side with your legs stacked upon each other and a dumbbell-free weight in your top hand. The other hand should be supporting your head or body if you're positioned at the top of the bench.
- Start with the dumbbell extended parallel to your shoulder.
- Without bending at the elbow, raise the dumbbell until it points to the ceiling. Bring the weight up in a diagonal movement rather than straight up.
- Slowly lower & repeat.
Benefits of Rear Delt Work
We've talked about how important it is for upper-body muscular development to work your rear deltoid muscle. But there's more to it than that. Here are four ways that strengthening your posterior delts will improve your health:
1. Improved Posture
The stronger your rear delts are, the better able they are to pull your shoulders back and down. This helps to overcome the hunched shoulder look that is so common today as a result of our screen obsession.
2. Greater Shoulder Stability
Shoulder stability is crucial when you're performing compound exercises like the clean and press. The stronger your rear delts are, the more solid your shoulder's base will be. That will make you far less likely to suffer injury when performing those heavy overhead exercises.
3. Balanced Muscle Development
The overemphasis on training the front and side delts and neglecting the muscle's rear head will result in muscle imbalances. The disproportionate strength and size between the heads that result make a person more susceptible to problems resulting from shoulder instability.
4. Enhanced Functional Movement
Virtually every functional movement of the upper body involves your shoulders. Having strong rear delts that are evenly developed in relation to the front and side heads will allow you to perform those functional movements with greater ease. Whether you're carrying groceries, hauling a suitcase, or using a wheelbarrow, you'll have greater shoulder strength and endurance to help you perform longer with less discomfort.
Looking for some shoulder inspiration? Discover how Arnold Schwarzenegger built his Olympia-winning shoulders here.
Rear Deltoid Training FAQ
Why should I train the rear delts separately?
The deltoids are a unique muscle group because each of the three heads has different muscle origin and insertion points. As a result, each head is able to move independently. That means that you need to do separate rear, lateral and front delt exercises to move each head through its full range of motion.
The range of movement of the front and side delts is different from the rear delts. So, when you are working your front and side delts, your rear delts are getting a free ride. This part of the deltoid will be underdeveloped unless you perform dedicated exercises for the rear delts.
How often should I train my rear delts?
You should train your rear delts, along with the front and side deltoids, once or twice per week. Ensure that you allow at least 48 hours between workouts to ensure the muscle recovers fully from the previous workout.
If you are working your shoulders along with another upper body muscle, hit the other muscle first. If you work your delts first, you'll exhaust them, providing a weak link when training the second body part.
Should I go heavy when training my rear delts?
No, you should not use a weight that is too heavy when training the rear delts. This relatively small muscle head responds best to a lighter resistance with higher reps. You will probably compromise your form if you try to go too heavy.
You should use a weight on your rear deltoid exercises that allow you to train in the 15-30 rep range. I recommend using fractional weight plates on your cable weight stack if your gym has them available.
Can I train my rear delts with bodyweight exercises?
Bodyweight exercises are not enough to specifically target the rear deltoid muscles. However, there are a number of bodyweight moves that effectively work the entire deltoid muscle. These include handstand push-ups, shoulder tap push-ups, and inverted rows. I recommend investing in a set of resistance bands if you don't have any equipment. This will allow you to replicate the rear delt cable fly exercise.
How can I prevent shoulder injuries when training my rear deltoids?
To prevent shoulder injuries when performing rear delt exercises, it is vital that you prioritize proper form. Do not swing or use momentum when doing rear delt exercises. Make sure that you are using a weight that allows you to do the movement without compromising your technique.
Wrap Up
The rear deltoid is a muscle head that often gets overlooked. As a result, a lot of people are walking around with only partially developed shoulders. By including dedicated rear delt exercises in your routine, you'll be able to produce fully capped delts with the mass and detail that marks a superior physique.
The three best rear delt exercises are all done on a cable machine, with the best of all being the rear delt cable fly. This should be your preferred posterior deltoid exercise if you have access to a double cable pulley machine. If not, choose one of the alternative exercises I've outlined in this article.
Train your rear delts, along with your front and side delts, once or twice per week. I recommend performing six sets, with a descending pyramid rep scheme from 30 down to 15 reps. Avoid going too heavy and keep your form strict for the best results.
Looking for some ideas to hit those side delts? Check out our article on the Best Lateral Delt Exercises.
Steve Theunissen
Author