Dumbbell One Arm Reverse Fly (with support) (VERSION 2) exercise animation (Male)

Dumbbell One Arm Reverse Fly (with support) (VERSION 2)

Target muscle
Deltoid Posterior
Synergist muscles
Deltoid Lateral, Infraspinatus, Teres Minor, Trapezius Lower Fibers, Trapezius Middle Fibers
Equipment
Dumbbell
Body part
Shoulders
Type
Strength

The dumbbell one arm reverse fly (with support) is a single-arm isolation exercise that targets the rear deltoid, with help from the lateral deltoid, infraspinatus, teres minor, and the lower and middle trapezius. Bracing your torso against support and working one arm at a time lets you isolate each rear delt cleanly and build upper-back balance and posture.

How to do the Dumbbell One Arm Reverse Fly (with support) (VERSION 2)

  1. 1Set an incline bench to roughly 30–45° and lie chest-down against the pad, or stand and brace your free hand on a bench so your torso is supported and stable.
  2. 2Hold a single dumbbell in the working hand with a neutral grip (palm facing inward), letting the arm hang straight down below your shoulder.
  3. 3Maintain a slight bend in the working elbow and keep it fixed there for the whole rep.
  4. 4Brace your core, keep your neck neutral, and pull your shoulder blade toward your spine to set the rear delt.
  5. 5Raise the dumbbell out to the side in a wide arc until your upper arm is roughly level with your torso.
  6. 6Squeeze the rear delt at the top, keeping the movement driven by the shoulder rather than the elbow.
  7. 7Lower the dumbbell under control along the same arc back to the start without letting it swing.
  8. 8Complete all reps on one side, then switch the dumbbell to the other hand and repeat.

Form tips

  • Lead the motion with your elbow and the back of your hand, not your palm, to keep tension on the rear delt instead of the traps.
  • Use a lighter dumbbell than you think — rear delts respond to clean reps and a strong top-end squeeze, not momentum.
  • Keep the elbow angle locked throughout; turning it into a press or a pull recruits other muscles and reduces rear-delt work.
  • Brace firmly against the bench so your spine stays neutral and only the working arm moves.
  • Pause briefly at the top of each rep to confirm you feel the contraction in the rear shoulder, not the lower back.

Common mistakes

  • Swinging the dumbbell up with body English, which shifts the load off the rear delt and onto momentum so the muscle barely works.
  • Going too heavy and shrugging, which hands the work to the upper traps and can strain the neck.
  • Bending and straightening the elbow during the rep, turning the fly into a row and losing the isolation.
  • Raising the arm too high past torso level, which over-recruits the traps and stresses the shoulder joint.
  • Rounding the back or twisting the torso instead of staying braced against the support, which risks the lower back.

Frequently asked questions

What muscles does the dumbbell one arm reverse fly work?

It primarily targets the rear deltoid (posterior delt), with the lateral deltoid, infraspinatus, teres minor, and the lower and middle trapezius assisting to move and stabilize the shoulder blade.

Why do the reverse fly one arm at a time with support?

Working one arm against support lets you brace your torso and focus fully on a single rear delt, which improves isolation and helps even out side-to-side strength differences.

How many sets and reps should I do?

Rear delts respond well to higher reps with lighter weight. Aim for 3–4 sets of 12–20 reps per arm, prioritizing a controlled tempo and a firm squeeze at the top.

Why don't I feel this in my rear delts?

Usually the weight is too heavy or you're swinging. Lighten the load, lead with your elbow, retract the shoulder blade, and stop when your upper arm reaches torso level rather than going higher.

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