Reverse Machine Flyes
Also called reverse pec deck, rear delt machine fly, rear delt fly machine
Quick answer
The reverse machine fly is a seated exercise on a rear-delt or pec deck machine where you sweep the handles from in front of you out to your sides with nearly straight arms. It targets the rear delts, with the middle back and traps assisting.
Written by the GymStreak coaching team · Updated
Muscles worked
Primary
Secondary
How to do Reverse Machine Flyes
- 1
Set the handles to the rear-delt position so they sit in front of you, then adjust the seat so the handles are at shoulder height.
- 2
Sit facing the machine with your chest against the pad and take the handles with a slight bend in your elbows.
- 3
Sweep your arms out and back in a wide arc until they are in line with your shoulders, making a T shape.
- 4
Pause for a moment, focusing on the backs of your shoulders.
- 5
Return the handles slowly toward the front, stopping just before the weight stack touches down.
Form cues
- Set the seat so the handles line up with your shoulders.
- Keep your chest on the pad and your elbows slightly bent and fixed.
- Think of pushing your hands out wide, not squeezing your shoulder blades hard.
- Stop when your arms line up with your body; going further brings in the traps.
- Keep the weight stack just off its rest between reps to hold tension.
Breathing: Breathe out as you sweep the handles out to your sides; breathe in as you bring them back to the front.
Common Reverse Machine Flyes mistakes
Bending the elbows more to move the weight
Lock in a slight elbow bend at the start and keep it the same for the whole set.
Shrugging the shoulders toward the ears
Keep your neck long and shoulders down so the rear delts, not the upper traps, do the work.
Leaning back off the pad
Keep your chest on the pad and pick a weight you can move without throwing your torso.
Seat set too high or too low
Adjust the seat so your arms travel straight out at shoulder height rather than angling up or down.
Sets and reps by goal
| Goal | Sets | Reps | Rest |
|---|---|---|---|
| Muscle growth | 3–4 | 8–15 | 60–90 s |
| Muscular endurance | 2–3 | 12–20 | 30–60 s |
Starting ranges in line with the ACSM guidance on resistance training. Pick a load you can lift with good form for every rep, and add weight or reps gradually.
Reverse Machine Flyes variations and alternatives
Variations
- Cable Rear Delt Flyes
Crossed cables give a similar arc and let you train one arm at a time.
- Rear Delt Dumbbell Raises
The bent-over dumbbell version, no machine needed.
- Seated Rear Delt Dumbbell Raises
Sitting and leaning over your thighs keeps your lower back out of it.
- Single-arm reverse machine fly
Working one side at a time helps you focus on a weaker rear delt.
Alternatives
- Dumbbell Incline Row
A chest-supported row with flared elbows that works the rear delts and middle back together.
- Seated Cable Rows
A compound pull for the middle back that also involves the rear delts.
- Barbell Upright Row
Trains the side delts and traps, pairing well with rear-delt work for rounder shoulders.
Reverse Machine Flyes FAQ
What muscles does the reverse machine fly work?
The reverse machine fly mainly works the rear deltoids on the back of your shoulders. The rhomboids and middle trapezius in your upper back help, especially toward the end of each rep as your shoulder blades move together. Your arms stay nearly straight, so the biceps do very little compared with a row.
Reverse pec deck vs dumbbell rear delt fly: which is better?
Both train the rear delts. The machine supports your chest and guides the path, so it is easy to learn, simple to load and good for controlled higher-rep sets. Dumbbell rear delt flies need no machine but ask you to hold a bent-over position, which makes it easier to cheat with momentum. Use whichever you can do with strict form.
How far back should I bring my arms on reverse flyes?
Bring your arms back until they are about in line with your shoulders, forming a T with your body. Going much further mostly comes from squeezing your shoulder blades together, which shifts work to the upper back. Stopping around that line and returning slowly keeps the focus on the rear delts.
How heavy should reverse machine flyes be?
The rear delts are small, so most people use a light to moderate weight for 8–15 or more reps. Choose a load you can move without bending your elbows further, shrugging, or leaning back. If you have to throw the handles to start a rep, lower the weight.
Sources
Related calculators
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