Rear Delts · Dumbbell
The Rear Delt Fly: Standing, Seated or Supported, and How to Choose
Everyone means something slightly different by this movement. The muscle does not care which one you pick — it cares whether your torso holds still.
Illustration adapted from Everkinetic via workout-guide, CC BY-SA 4.0. Full credits.
| Equipment | Dumbbell |
|---|---|
| Back zone | Rear Delts · Upper Back |
| Muscles | Rear Delts · Infraspinatus |
| Level | Beginner |
| Typical work | 3 × 12–15 |
| Where | Home or gym |
What is the Rear Delt Fly?
The rear delt fly is a dumbbell exercise for the rear delts and infraspinatus. Hinged forward with softened elbows, you raise the dumbbells out wide until the arms reach the height of your back. It is a family rather than a single movement: standing, seated and chest-supported versions all load the same arc from a different torso.
The one cue that matters: Hinge forward, soften your elbows, and raise the dumbbells out wide — light weight, no swinging.
Why the Rear Delt Fly is worth doing
- Three setups from one pair of dumbbells, so there is a version for almost any bench, chair or empty floor
- The arc runs straight up against gravity, so the load never disappears the way it does in a standing movement
- It reaches the infraspinatus, which only eight of the 77 exercises in the library touch at all
- Light dumbbells are the correct dumbbells, which makes it one of the cheapest movements to own equipment for
How to do the Rear Delt Fly
- Choose the torso Standing hinged, seated with your chest over your thighs, or face down on an inclined bench. Pick whichever one you can hold perfectly still for fifteen reps — that is the only criterion that matters.
- Set the elbows once Soften both elbows into a slight bend and keep exactly that angle for the whole set. The app’s cue is explicit about this: soften the elbows, then raise wide.
- Hang the weights under your shoulders Palms facing each other, arms straight down from the shoulder joint. This is the bottom of every rep.
- Raise out wide Sweep the dumbbells out to the sides until the arms are level with your back. Wide, not back — a rep that travels toward your hips is a row.
- Lower without swinging Two seconds down, all the way to the start. No swinging is the other half of the cue, and it applies to the descent as much as the lift.
Muscles worked
The rear delts move the arm from hanging to horizontal, which is the posterior deltoid’s defining job. The infraspinatus contributes the outward rotation of the upper arm as the hands turn over at the wide end.
Which version you pick changes none of that. What it changes is what runs out first. Standing hinged, the hamstrings and the muscles holding your back flat usually tire before the delts. Seated, the hinge is shorter and easier to keep. Chest-supported, nothing has to be held at all and the set ends when the target muscle is finished, which is the point of the position.
The bent-over rear delt raise is the strict standing member of this family, with a pinky-led path that leans harder on the infraspinatus. Treat that page as the how, and this one as the which.
| <a href=”/back-muscles/rear-delts/”>Rear Delts</a> | Posterior deltoid — Rounded shoulders from behind — the detail that finishes a back. |
|---|---|
| <a href=”/back-muscles/infraspinatus/”>Infraspinatus</a> | Infraspinatus & teres minor — The plate under the shoulder blade. Separation, and healthy shoulders. |
Form tips
- Pick the version by what fails first. If your set ends because your back position went, you chose the wrong setup, not the wrong weight.
- Palms facing, or pinkies up. Neutral palms is the simplest default. Rotating the little fingers up as you rise adds the infraspinatus, at the cost of a little load.
- Chest still, head down. Looking up in the mirror lifts the chest and unwinds the hinge. Eyes at the floor.
- The weight is smaller than you want. 12 to 15 reps with a long straight arm is a genuinely small load. Nobody has ever been held back by too light a rear delt fly.
Common mistakes
- Turning it into a row
- Bending the elbows and driving them toward your hips is a row, and it hands the work to the rhomboids and lats. Arms stay long, path stays wide.
- Swinging the weights up
- A small bounce of the torso can throw far more weight than the delts can lift, and it is the failure the app’s own cue names. If the torso moves, the rep does not count.
- Stopping short at the top
- The arms should reach the height of your back. Half reps here are very common because the last few inches are where the load is highest.
- Pulling the shoulder blades together
- Retraction moves the work to the mid back. Keep the blades quiet and let the arms travel.
Sets, reps and where it fits
Three sets of 12 to 15, at the end of a pulling day. Rear delts are small and recover quickly, so two exposures a week beat one, and this movement is easy to repeat because it costs almost nothing to recover from.
If your scan puts Rear Delts lowest, pair this with a movement whose resistance peaks somewhere else — a band pull-apart is hardest at the finish, a cable fly is hardest at the widest point, and this one is hardest at the top. Three curves, one muscle. The rear delt guide covers how the zone reads in a scan.
No dumbbell? Do this instead
No dumbbells? A banded rear delt fly holds the same hinge with a band under your feet. In a gym, the reverse pec deck gives you the same arc with a pad holding your chest, which removes the position from the equation entirely.
Variations and similar exercises
- Bent-Over Rear Delt Raise
- The strict standing member of the family, torso near parallel and pinkies leading. Pick it when you want the infraspinatus in as well.
- Reverse Pec Deck
- Seated with a chest pad. Pick it when holding the hinge is what ends your sets.
- Banded Rear Delt Fly
- The same hinge with a band instead of iron. Pick it at home, or when the smallest dumbbell you own is still too heavy.
7 Rear Delt Fly alternatives, by equipment and level →
Compared: Face Pull vs Rear Delt Fly · Rear Delt Fly vs Reverse Pec Deck
Frequently asked questions
What is the difference between a rear delt fly and a reverse fly?
Nothing consistent — they are the same movement under two names, and both describe raising the arms out wide from a hinged position. The differences that matter are the ones between setups: standing, seated and chest-supported, which change what tires first rather than what gets trained.
How heavy should a rear delt fly be?
Light. The library default is 12 to 15 reps with a nearly straight arm, which is a long lever on a small muscle. If you are choosing dumbbells by what looks reasonable rather than what you can raise without swinging, they are too heavy.
Should rear delt flys be seated or standing?
Whichever torso you can hold still for the whole set. Standing hinged is hardest to keep and is often ended by the lower back rather than the delts. Seated shortens the hinge; chest-supported removes it. The muscle gets the same arc in all three.
Why can’t I feel rear delt flys?
Usually because the elbows are bending and the arms are travelling backwards rather than sideways, which turns the rep into a row. Fix the elbow angle before the first rep, keep the path wide, and drop the weight far enough that neither has to change.
Should the Rear Delt Fly be in your plan?
BackMaxx scores your rear delts from one photo and builds the week around whatever is lagging — so the Rear Delt Fly only shows up when it is the right call.
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