Rear Deltoid Training: Reverse Pec Deck vs Cable Face Pulls vs Incline Dumbbell Flyes

The best rear delt exercise is the one you can do with clean form, close to failure, and progress for months. Reverse pec deck, cable rear delt flies and rows all load the posterior deltoid well, and no study has crowned a winner for muscle growth.

That sounds like a cop-out. It is not. It means the details (grip, arm angle, load, rep range) matter more than the machine. This article sits inside our complete shoulder and delt training guide, and it focuses on the back of the shoulder, the head most lifters skip.

What do the rear delts actually do?

The posterior deltoid pulls your upper arm backward and out to the side. In gym terms, it is the muscle that moves when you do a reverse fly. If the anatomy is new to you, start with our breakdown of the three deltoid heads.

Most pressing already hits the front delt, and lateral raises handle the side. The rear head gets little from bench pressing or a standard front overhead press. Rows help, which we will get to.

Reverse pec deck vs cable fly vs face pull: how do they compare?

Here is the honest summary. EMG studies show these exercises all activate the rear delt. What we do not have is a trial that trains one group on pec deck and another on cables for 12 weeks and measures growth. So the comparison below is about practicality, not proven superiority.

Exercise	Best for	Watch out for
Reverse pec deck	Stable, easy to push close to failure	Seat height that puts arms too high or low
Cable rear delt fly	Smooth tension, easy angle changes	Cable height and body lean changing the line of pull
Face pull	Upper back, external rotation, higher reps	Turning it into a trap and rhomboid pull
Chest-supported dumbbell fly	Cheap, works anywhere	Little resistance at the bottom of the rep
Rows and pull-ups	Heavy loading, big muscle groups	Rear delts may not be the weak link in the movement

Reverse pec deck

This is the default for most people. The pad fixes your torso, the path is guided, and you can focus on pushing the handles back. You also do not need to balance anything, so it is easy to train hard.

The downside is fit. Machines are built for an average body. If the handles start too far forward or your shoulders roll up, adjust the seat or skip it.

Cable rear delt fly

Set two pulleys at about shoulder height and cross the cables so each hand holds the opposite handle. Step back until there is light tension at the start. Or do it one arm at a time, which makes the path easier to feel.

Cables keep tension on the muscle through the arc, though the exact resistance depends on how you stand and where the pulley sits. Our guide to cable setup, pulley heights and angles covers this in more detail.

Face pulls

Face pulls pull the rope toward your face with the elbows high, then rotate the hands up. That mixes rear delt, mid-back and rotator cuff work. Treat it as a bonus, not your only rear delt exercise. The full technique lives in our face pull form guide.

Incline (chest-supported) dumbbell flyes

Lie chest down on a bench set at about 30-45 degrees and raise light dumbbells out to the sides. It costs nothing if your gym has no machine. Because gravity pulls straight down, the exercise is hardest near the top, when your arms are close to parallel with the floor, and easiest at the bottom where the dumbbells hang.

What does the research say about grip and arm position?

Two details have real data behind them.

Neutral vs pronated grip

Schoenfeld and colleagues (2013) had 19 resistance-trained men do reverse fly machine sets to failure with a neutral and a pronated grip. Mean posterior deltoid EMG was significantly higher with the neutral grip (p = 0.046), and so was infraspinatus activity (p = 0.002). The authors used surface EMG, which measures electrical activity, not muscle growth.

So a neutral grip, palms facing each other, looks like the better first choice. This is one small acute study in young men. It does not prove a neutral grip builds more muscle, but it is a reasonable tiebreaker.

Arm angle

The usual coaching cue is to keep your upper arms at about shoulder height, roughly perpendicular to your torso, rather than drifting up toward your ears or down toward your hips, so the rear delt does the work and the traps do not. This cue is common practice, not a tested rule. The closest data comes from Reinold et al. (2004), who used intramuscular electrodes in 10 healthy people. Prone horizontal abduction at 100 degrees of abduction with full external rotation produced the highest posterior deltoid activity of the seven exercises tested, at 88% of maximal voluntary isometric contraction.

That tells us the position, arms out to the side and thumbs up, loads the rear delt hard. It does not tell us it is best for growth, and the study was not a lifter-style trial.

How do rows and pull-ups fit in?

A 2024 systematic review pulled together 33 EMG studies on the three deltoid heads. For the posterior deltoid, pull-ups gave the greatest group activation, with standard pull-ups and suspension inverted rows the top individual exercises. For the other heads, other exercises led.

Not a reason to ditch reverse flies. Rows are heavy, big-muscle moves, and the rear delts probably get some work. If your back training is solid and your rear delts still lag, add direct sets. Our guide to chest-supported rows for the upper back shows how to row without your rear delts dropping out.

How do I keep the traps and rhomboids from taking over?

Excessive scapular retraction is the classic fault. You lean back, squeeze your shoulder blades together and the movement turns into a mid-back row. The rear delt is along for the ride.

Fix it like this:

1. Lower the load. If you can’t pause for one second at the end of the rep, it is too heavy.
2. Think about moving your hands apart, not pinching your shoulder blades.
3. Keep your shoulders down, not shrugged toward your ears.
4. Stop the rep when your arms are about in line with your body, not pulled behind it.
5. Keep your chest on the pad or bench.

The most common mistake here is ego loading: stacking the pin way too far down the stack and finishing every rep with a jerk. Rear delts are small and respond poorly to that.

What rep range works best for rear delts?

Roughly 10-20 reps is a practical zone. Rear delt exercises are awkward to load heavily, and light-to-moderate loads are easier to control. The evidence supports this. A 2017 meta-analysis of 21 studies found similar hypertrophy with low-load and high-load training when sets were taken to failure, while heavy loads favored 1RM strength. The 2021 review of the repetition continuum proposes that muscle growth can occur across a wide spectrum of loading zones.

None of that research looked at rear delts specifically, so treat it as a general principle, not a rear delt-specific result.

How many sets and how often to grow rear delts fast?

Faster results come from consistent weekly volume, not from exotic exercises. A meta-regression by Schoenfeld and colleagues (2017) of 15 studies found a graded dose-response between weekly sets and muscle size, with each added set linked to a small gain. That data covers muscles in general, not rear delts. A larger 2026 meta-regression of 67 studies confirmed that growth rises with weekly volume but with diminishing returns, and found frequency mattered little for growth once volume was set.

A practical starting point:

• 6-12 hard weekly sets for rear delts, rows included
• Split across two or three sessions
• One fly option as your main lift, one lighter option (such as face pulls) as a finisher

If your shoulders ache, cut sets before you add them. Our 3D shoulder protocol shows how to fit all three heads into a week. You can also plug your sets into the training volume calculator to see your weekly total.

Is it safe? When to see a doctor

Rear delt training is generally low-risk when the load is light and the range is comfortable. Scapular position matters for shoulder comfort. Escamilla and colleagues (2009) reviewed shoulder rehab exercises and noted that scapular retraction, compared with protraction, widens the subacromial space during elevation. That is one reason controlled retraction is useful, and also why swinging, shrugged reps are a poor idea.

Sharp pain, pain at night, numbness, tingling or sudden weakness are reasons to stop and see a doctor or physiotherapist. Do not push through them.

A simple rear delt template for Indian gym setups

Many Indian commercial gyms have a pec deck that doubles as a reverse fly, plus a cable crossover. That is enough. Here is a sample:

• Pull day: reverse pec deck, 3 sets of 12-15, neutral grip if available
• Push day: cable rear delt fly or chest-supported dumbbell fly, 2-3 sets of 15-20
• Optional finisher: face pulls, 2 sets of 15-20

Eat enough protein through dal, paneer, curd, soya or eggs, sleep properly, and be patient. Small muscles are slow to change visibly. Photograph your side delts and back every four weeks under the same light.

The bottom line

The best rear delt exercise is a controlled one you can progress. Use a neutral grip on the reverse pec deck when possible, keep reps in the 10-20 zone, avoid pinching your shoulder blades, and mix in cables, face pulls and rows. Then count your weekly sets and add only when progress stalls.