The reverse pec deck, also called the reverse fly machine, trains shoulder horizontal abduction with a fixed machine path. The posterior deltoid is the main target. The middle trapezius and rhomboids help manage the shoulder blades, while other shoulder muscles stabilize the joint.
Set the seat so your hands and elbows travel roughly at shoulder height, keep a small fixed bend in the elbows, and move the upper arms out and back without shrugging. If the machine is unavailable or uncomfortable, cables, bands, and chest-supported dumbbell flies can reproduce the movement more closely than rows or face pulls.
Reverse Pec Deck Muscles Worked
| Muscle | Role |
|---|---|
| Posterior deltoid | Moves the upper arm away from the front of the body in horizontal abduction. |
| Middle trapezius and rhomboids | Retract and control the shoulder blades, especially as the arms move toward the end of the range. |
| Infraspinatus and teres minor | Stabilize and externally rotate the shoulder. The exercise is not a rotator-cuff isolation movement. |
| Middle deltoid | Assists depending on arm path, grip, and machine design. |
The rear delts move the upper arms. The mid traps and rhomboids move the shoulder blades. Those actions happen together, but they are not interchangeable. If you pinch the shoulder blades hard before the arms move, the exercise can become more upper-back dominant and shorten the rear delts’ working range.
A study of 19 resistance-trained men compared neutral and pronated grips on a reverse fly machine. Neutral grip produced modestly higher posterior-deltoid and infraspinatus EMG in that session. This acute result does not prove greater long-term muscle growth, but it supports trying both grips and using the one that feels stable and keeps the target movement clean. See the study on PubMed.
How to Do the Reverse Pec Deck
- Adjust the machine arms. Set them for a reverse-fly path rather than a chest-fly path.
- Set the seat height. When you hold the handles, your upper arms should travel close to shoulder height without forcing the shoulders upward.
- Sit facing the pad. Keep your chest supported, feet planted, and ribs controlled.
- Choose a grip. Use the vertical handles for a neutral grip or horizontal handles for a pronated grip if the machine offers both.
- Lead with the upper arms. Open the arms out and back while keeping a small, fixed elbow bend.
- Stop before compensation. Finish when the upper arms reach your controlled end range, not when the stack or machine tells you to overreach.
- Return slowly. Let the arms come forward under control without allowing the weight stack to crash.
Common Reverse Pec Deck Mistakes
- Setting the seat too low: This can turn the path into a high pull and encourage shrugging.
- Using too much weight: Momentum, shortened range, and elbow movement usually appear before the target muscles receive better training.
- Pinching the shoulder blades first: Let the upper arms initiate the movement, then allow the shoulder blades to move naturally.
- Changing elbow angle during the rep: Bending and straightening the elbows introduces triceps movement and changes the lever.
- Forcing the hands far behind the torso: More range is not better when the shoulder rolls forward or the chest leaves the pad.
- Treating discomfort as a form cue: Adjust the seat, grip, range, or load. Stop if pain persists.
Sets and Reps
These are practical starting ranges for a rear-delt accessory, not outcomes or prescriptions tested by the cited EMG and resistance-training studies. Use the range that lets you keep the arm path consistent and progress without shrugging.
| Goal | Starting range | Priority |
|---|---|---|
| Learn the movement | 2 sets of 12 to 15 | Light load and repeatable arm path. |
| Muscle gain | 3 to 4 sets of 8 to 20 | Full controlled range with one to three good reps in reserve. |
| Higher-rep accessory work | 2 to 3 sets of 15 to 25 | No shrugging or shortened reps as fatigue builds. |
The rear delts do not require one magic rep range. Use a load that lets you control the lever and progress reps or weight over time. The reverse pec deck can fit after pressing, rowing, or pulling work in a shoulder workout.
Best Reverse Pec Deck Alternatives
| Alternative | Equipment | Movement match | Main tradeoff |
|---|---|---|---|
| Cable reverse fly | Dual cables | Very close | More setup freedom, less torso support. |
| Band reverse fly | Resistance band | Close | Resistance rises toward the finish. |
| Chest-supported dumbbell fly | Dumbbells and bench | Close | Gravity changes the loading through the range. |
| Bent-over dumbbell fly | Dumbbells | Close | Requires more trunk control. |
| Single-arm cable fly | One cable | Close | More anti-rotation demand. |
| Face pull | Cable or band | Partial | Adds elbow flexion and external rotation. |
| Rear-delt row | Dumbbells or cable | Partial | Allows more load but uses more upper-back and arm musculature. |
| YTWs | Bodyweight or very light weights | Partial | Low external loading and several arm paths. |
The closest substitute depends on why you chose the machine. For rear-delt loading with a similar arm path, start with a cable or band reverse fly. For greater stability, use a chest-supported dumbbell fly. Face pulls and rows are useful exercises, but they are not direct copies because the elbows and shoulder blades move differently.
1. Cable Reverse Fly
A dual-cable reverse fly closely matches the machine’s horizontal-abduction action while letting each arm follow a comfortable path. Start with the pulleys near shoulder height, cross the cables if needed, and move the upper arms out without shrugging.
Coaching cue: Keep the elbows softly bent and fixed. If your hands race behind your elbows, the movement has turned into an arm action.
- Best for: Closest gym-based substitute
- Equipment: Dual cable station
- Tradeoff: Less torso support than the machine
Use our full cable rear-delt fly guide for detailed setup options.
2. Resistance Band Reverse Fly
Anchor a band at chest or shoulder height and pull the hands apart until the upper arms line up with the torso. Band resistance increases as it stretches, so the finish may be the hardest part.
Coaching cue: Step closer to the anchor or use a lighter band if the final third forces you to shrug.
- Best for: Home and travel training
- Equipment: Anchored resistance band
- Tradeoff: Rising resistance differs from most machines
3. Bent-Over Dumbbell Reverse Fly
Hinge at the hips, brace the torso, and raise light dumbbells out to the sides. The arm action is similar, but holding the bent-over position adds fatigue that the chest-supported machine avoids.
Coaching cue: Keep the torso still. If the chest rises on every rep, reduce the load.
- Best for: Minimal-equipment training
- Equipment: Dumbbells
- Tradeoff: Greater trunk and hip demand
4. Lying Dumbbell One-Arm Rear Delt Raise
Lie on your side and raise a light dumbbell through a rear-delt-focused arc. This unilateral option can help you concentrate on one shoulder, but the resistance path is not identical to a machine fly.
Coaching cue: Use a short controlled range. Stop before the shoulder rolls forward or the torso rotates.
- Best for: Light unilateral work
- Equipment: One dumbbell
- Tradeoff: Unusual setup and limited loading
5. Bent-Over One-Arm Band Rear Delt Raise
Anchor a band low, hinge, and move one arm out and back. The unilateral setup makes side-to-side differences obvious, but it also creates rotational demand through the torso.
Coaching cue: Square the shoulders to the floor and resist the band’s pull across your body.
- Best for: Unilateral home training
- Equipment: Resistance band and low anchor
- Tradeoff: Less stability and rising resistance
6. YTWs
YTWs combine three arm positions to train scapular control and several shoulder muscles with very light resistance. They are useful for low-load accessory work, but only the T position closely resembles a reverse fly.
Coaching cue: Move slowly and keep the neck relaxed. More range is not useful if the shoulders shrug toward the ears.
- Best for: Low-load control work
- Equipment: None or very light dumbbells
- Tradeoff: Not a close loading match
7. Incline Bench Rear Delt Fly
Lie chest-down on an incline bench and raise dumbbells out to the sides. The bench removes much of the torso momentum found in a standing bent-over fly, making this one of the better dumbbell substitutes.
Coaching cue: Keep the chest on the pad and choose a bench angle that lets the arms move without the dumbbells hitting the floor.
- Best for: Stable dumbbell training
- Equipment: Dumbbells and incline bench
- Tradeoff: Gravity creates less resistance near the bottom
8. Lying Supine Cable Raise
Lie on a bench between high cable pulleys and pull the handles down and outward. The bench stabilizes the torso, although the cable direction makes this a less direct match than a standing cable reverse fly.
Coaching cue: Set the bench and pulleys before loading the stack, and check that the cables clear your head and bench.
- Best for: Supported cable work
- Equipment: Dual cables and bench
- Tradeoff: More setup and a different pull angle
9. Bent-Over One-Arm Cable Fly
Set one cable low, hinge with the free hand supported, and raise the working arm out. This version offers a long cable path and unilateral loading, but maintaining a square torso takes attention.
Coaching cue: Let the shoulder move the arm. Do not rotate the rib cage to finish the rep.
- Best for: Unilateral cable loading
- Equipment: Single low cable
- Tradeoff: Greater torso-stability demand
Reverse Pec Deck vs. Face Pull and Rear-Delt Row
| Exercise | Main action | Typical use |
|---|---|---|
| Reverse pec deck | Shoulder horizontal abduction with machine support | Direct rear-delt work with a repeatable path |
| Face pull | Horizontal pull plus elbow flexion and external rotation | Rear delts, upper back, and external rotators with a different pattern |
| Rear-delt row | Row with elbows away from the torso | Heavier upper-back and rear-delt loading, with more assistance |
Use the reverse pec deck when you want a stable fly pattern. Choose a face pull when you want a combined pull and external-rotation pattern; our face-pull alternatives page covers that exercise family. Choose a rear-delt row when loading the upper back more broadly is part of the goal.
Who Should Use the Reverse Pec Deck?
The machine suits lifters who want direct rear-delt work without supporting a bent-over torso. It can be useful after pressing or rowing because it is easy to set up and progress. It is not a posture treatment or a substitute for individualized shoulder rehabilitation.
If the machine path pinches, causes sharp pain, or forces an uncomfortable range, change the seat, grip, load, or exercise. Persistent shoulder pain, weakness after an injury, or instability deserves assessment from a qualified clinician.
FAQ
Are reverse pec deck flys necessary?
For complete deltoid development, you need to work all three heads of the muscle. The reverse pec deck fly does a good job of working the rear deltoid. All of the alternatives listed in this article are just as good, if not better.
How many reps should I do for the rear deltoids?
The rear deltoids are a small muscle group that responds best to high reps. This will also help keep the exercises momentum-free. You should ideally stay in the 15-30 rep range.
How often should I work the rear deltoids?
For best muscle and strength-building results, you should work your muscles, including the rear delts, every 3-4 days. Training the rear delts twice per week, with a three-day gap between workouts is recommended.
Movement match: Cable, band, and chest-supported reverse flies stay closest to the machine. Face pulls and rows train different patterns.
Choose the Reverse Pec Deck for Stable Rear-Delt Work
The reverse pec deck is a rear-delt exercise first and an upper-back assistance movement second. Set the seat so the arms travel comfortably near shoulder height, keep the elbow angle fixed, and use a load you can return under control. When the machine is unavailable, choose a cable, band, or chest-supported dumbbell fly for the closest match. Rows and face pulls remain useful, but they solve a different training problem.
Interested in measuring your progress? Check out our strength standards for Bench Press, Squat, Deadlift, and more exercises.
