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Dumbbell Decline One Arm Fly

A single-arm decline fly that isolates one side of the lower chest while the free hand stabilizes, useful for fixing left-right strength and size gaps.

ChestDumbbellHorizontal adduction
GoLightWeight mediadumbbell-decline-one-arm-fly

Demonstration coming soon

Primary

Pectoralis major

Secondary

Anterior deltoidsCoreBiceps

Equipment

Dumbbell

Pattern

Horizontal adduction

Setup

  1. 01Set a decline bench to roughly 15 to 30 degrees and secure the feet.
  2. 02Lie back holding one dumbbell extended above the lower chest, palm in.
  3. 03Grip the bench or place the free hand on the ribs for stability.
  4. 04Set a slight fixed bend in the working elbow.

Execution

  1. 01Lower the dumbbell out to the side in a wide arc until you feel a chest stretch.
  2. 02Keep the elbow bend constant through the descent.
  3. 03Reverse the arc, squeezing the chest to bring the dumbbell back over the body.
  4. 04Stop above the chest midline without rotating the torso.

Checkpoints

  • -Torso stays square on the bench despite the one-sided load.
  • -Elbow angle never changes during the rep.
  • -The stretch is felt in the pec, not the front of the shoulder joint.
  • -The arc is the same width on every rep.

Common mistakes

  • -Twisting the torso toward the working arm.
  • -Turning the fly into a press by bending the elbow at the bottom.
  • -Dropping too deep and straining the shoulder capsule.
  • -Using a weight suited for two-arm flys.

Programming notes

  • -Use 2 to 3 sets of 10 to 15 reps per side, starting with the weaker side.
  • -Match reps to the weaker side to close asymmetries over time.
  • -Program after a bilateral press, not as a main strength movement.

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