Rear Delt Fly Machine
The rear delt fly machine is an isolation exercise targeting the posterior deltoid. Using a dedicated rear delt machine allows for precise targeting of the often-underdeveloped rear shoulder, improving overall shoulder balance and upper back strength.
How to do it
- Sit on a rear delt fly machine and adjust the seat so the handles are at shoulder height.
- Grip the handles with both hands and keep a slight bend in your elbows.
- Pull the handles outward and backward in a controlled arc, driving your elbows back.
- Squeeze your rear delts and shoulder blades together at the end of the range of motion.
- Slowly return the handles to the starting position and repeat for the desired number of repetitions.
Form cues
- Keep a soft bend in your elbows throughout the movement.
- Drive your elbows straight back, not up.
- Squeeze your shoulder blades together briefly at peak contraction.
- Return the weight with control without letting the stack slam.
Breathing: Exhale as you pull the handles back and squeeze your shoulder blades; inhale as you slowly return to the starting position.
Common mistakes
- Using too much momentum by jerking the weight, which shifts work away from the rear delts.
- Bending the arms too much into a rowing motion, which recruits the larger upper back muscles instead of isolating the rear shoulders.
- Shrugging the shoulders up toward the ears, causing neck strain and tension.
- Rushing the negative (return) phase, missing out on valuable time under tension.
Muscles worked
Primary: delts. Secondary: rhomboids, traps.
Suggested sets & reps
Get fitter
3 sets × 10–15 reps, rest 60 s
Lose weight
3 sets × 12–15 reps, rest 45–60 s
Build muscle
3–4 sets × 10–12 reps, rest 60–90 s
Easier, harder & alternatives
Make it easier
Make it harder
Take care if…
- If you feel sharp shoulder discomfort, ease off and choose a gentler movement.
General educational guidance, not medical advice. Stop on sharp pain and check with a qualified professional if unsure.
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Start free →Frequently asked questions
What if I feel this in my upper back instead of my shoulders?
That usually happens if you bend your arms too much or pull with your hands. Focus entirely on driving your elbows backward in a wide arc.
How many times a week can I do rear delt exercises?
Most beginners benefit from training shoulders 2 to 3 times per week with at least one rest day between sessions.
Can I do this exercise if I don't have the machine?
Yes, you can easily substitute dumbbells or resistance bands to perform a bent-over rear delt fly at home.