What is the machine reverse flyes?
Machine reverse flyes, often called the reverse pec deck, are a seated isolation exercise for the posterior deltoids. You sit facing the pad, grab the handles in front of you with slightly bent arms, and sweep them back in a wide arc until they are level with your torso. Because the machine locks your torso in place, there is no lower-back fatigue and no way to cheat with momentum like on bent-over raises. It is the simplest tool for fixing the rear-delt deficit that pressing-heavy programs create, and it works for everyone from first-timers to advanced bodybuilders.
How to do the machine reverse flyes
- 1
Set the seat and handles
Adjust the seat so the handles sit at shoulder height and your arms are parallel to the floor. Chest against the pad, feet planted.
- 2
Grip light, elbows slightly bent
Take a neutral grip, palms facing each other. Fix a 10-20° bend in the elbows and freeze it for the whole set.
- 3
Sweep back, don't row
Open your arms in a wide arc until your hands are level with your shoulders. Lead with the elbows and move from the shoulder joint, not the shoulder blades.
- 4
Control the return
Control the return over 2-3 s and keep the plates from kissing between reps. Constant tension is the whole point of the machine.
Pro tip
Imagine your hands are hooks and your forearms don't exist. Drive every rep from the back of the shoulder and pause one second in the open position. If you can't pause, the weight is too heavy.
Common mistakes
Going too heavy.
Ego loads turn the movement into a shrug-and-swing. Rear delts respond to light weight, strict form and lots of reps.
Squeezing the shoulder blades.
Full scapular retraction hands the work to rhomboids and traps. Keep the blades quiet and move the arm in the shoulder socket.
Pumping the elbows.
Bending and straightening the arms turns the fly into a triceps pressback. Set the elbow angle once and never change it.
Chest leaving the pad.
Arching away from the pad means you're heaving the stack with your back. Stay glued and let the delts do everything.
Variations and progressions
Easier
Band pull-apart
Same arc with an elastic band. Teaches the pattern with almost no load and can be done daily, anywhere.
Harder
Paused reverse flyes
Hold 2 s in the fully open position every rep. Brutal at half your usual weight, and impossible to cheat.
No machine?
Bent-over dumbbell rear delt fly
Hinge to near-parallel and fly light dumbbells out. Same muscles, more core and lower-back demand.
How to program it
Three protocols by goal. Pick one per cycle and aim for progression on load or distance.
| Goal | Sets × distance | Load | Rest |
|---|---|---|---|
| Hypertrophy | 3 × 12-15 | Light-moderate, RPE 8 | 60-90 s |
| Shoulder health | 2 × 15-20 | Light, 1 s pause per rep | 45-60 s |
| Pump finisher | 2 × 15 + drop set | Drop 30-40% after failure | 90 s |
Machine Reverse Flyes FAQ
Palms down or palms facing each other?
Both hit the rear delts, but the neutral grip (palms facing each other) usually feels stronger and lets the arm sweep back in its natural groove. Try one set of each at the same weight and keep the grip where you feel the back of the shoulder burn most. For most lifters that's neutral.
Why don't I feel my rear delts on this machine?
Two culprits, almost always: too much weight and too much shoulder blade. Cut the load in half, keep the blades still, slow the negative to 3 s and pause in the open position. If your traps still take over, drop the handles slightly below shoulder height. The burn shows up within two sessions.
How often can I train rear delts?
Two to three times a week, easily. Rear delts are small, recover fast and are chronically underworked compared to the front of the shoulder, which gets hammered by every press. Aim for 10-20 quality sets weekly across reverse flyes, face pulls and rows, and your shoulder balance and posture will thank you.
