Rear Delt Fly

Also known as: reverse fly, rear delt raise, bent over reverse fly, rear deltoid fly

Rear delts are the most neglected muscle on most lifters, and the rear delt fly is the most direct way to fix that. Hinged forward with light dumbbells, you sweep your arms out to the sides and let the back of the shoulder do the work, with the mid traps and rhomboids assisting. Strong rear delts round out the shoulder from every angle and help balance all the pressing in a typical program.

PRIMARY MUSCLEShoulders
ALSO WORKSUpper back
EQUIPMENTDumbbell
TYPICAL SETS × REPS3 × 15–20

How to do the rear delt fly, step by step

  1. Hold a light dumbbell in each hand and hinge at the hips until your torso is close to parallel with the floor, back flat.
  2. Let the dumbbells hang below your chest with palms facing each other and elbows slightly bent.
  3. Keeping that elbow bend fixed, raise both arms out to the sides in a wide arc.
  4. Lead with the elbows and stop when your upper arms are level with your back.
  5. Pause briefly at the top without squeezing the shoulder blades all the way together.
  6. Lower the dumbbells slowly back under your chest and repeat without swinging your torso.

Form cues that fix most reps

Keep a soft squeeze in the shoulder blades but let the rear delt, not the traps, lift the arm.

Point your pinkies toward the ceiling at the top of each rep to bias the rear delt.

If your torso bobs up and down, brace on an incline bench chest-down and take the lower back out of it.

Common mistakes (and the fix)

Standing too upright so the movement becomes a lateral raise
Hinge until your chest faces the floor.
Using heavy dumbbells and rowing the weight up with bent arms
Keep the elbow angle frozen and drop the load.
Retracting the shoulder blades hard and letting the traps take over
Think of the arms sweeping wide, not the blades pinching.

Rear Delt Fly sets and reps

Match the rep range to your goal, not the other way around. These are the standard evidence-based ranges:

GoalSets × RepsRest
Strength3–5 × 3–62–3 min
Muscle growth3–4 × 8–1260–90 sec
Endurance2–3 × 15–2030–60 sec

How our free programs prescribe it

Rear Delt Fly FAQ

What muscles does the rear delt fly work?

The posterior deltoid is the target, with the mid traps and rhomboids assisting as the arms sweep back. Trained strictly, it is one of the only movements that puts the rear delt first rather than treating it as an afterthought to rowing.

How many sets and reps should I do?

Rear delts handle high volume well: 3–4 sets of 15–20 reps with a deliberate pause at the top is a good prescription. They recover fast, so training them two or three times per week is reasonable.

Rear delt fly vs face pull — do I need both?

They overlap heavily, so you don't need both in every session. The fly isolates the rear delt a bit more, while the face pull adds external rotation and mid-trap work. Rotating them, or picking whichever your gym setup makes convenient, covers the base either way.

More shoulders exercises

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