Exercise Profile
  • Target Muscle Group
  • Exercise TypeStrength
  • Equipment RequiredDumbbell
  • MechanicsIsolation
  • Force TypePull
  • Experience LevelIntermediate
  • Secondary Muscles
Target Muscle Group


Shoulders Muscle Anatomy Diagram

One-Arm Seated Rear Delt Fly Overview

The one-arm seated dumbbell rear delt fly is a great exercise to assist you in building a complete set of shoulders as it targets the rear delts, an often lagging muscle for many lifters.

Strengthening the rear delts can lead to improved posture and a greater level of strength on other lifts.

Performing unilateral movements can help improve weaknesses, balance your strength and aesthetic physique, and work towards reducing injuries by addressing imbalances in the body.

One-Arm Seated Rear Delt Fly Instructions

  1. Grab a dumbbell with a neutral grip and sit on the edge of a flat bench. 
  2. Allow your arm to hang by your side. You can place your non-working forearm across your knee for stability.
  3. Bring your torso forward by bending at the waist. Keep your head up and your eyes facing forward. This is the starting position.
  4. Take a deep breath and pull the dumbbell towards the ceiling using the rear deltoids, until parallel or as much as your range of motion allows.
  5. Slowly lower the dumbbell back to the starting position under control.
  6. Repeat for the desired number of repetitions, and then repeat on your opposite arm.

One-Arm Seated Rear Delt Fly Tips

  • Focus on the rear deltoids and not the scapular retractors. Keep movement at the shoulder blade should be limited.
  • If you experience shoulder pain during the movement then it may be beneficial to rotate the dumbbells until the thumbs point away from one another and the palms are facing forward. This is also known as a supinated grip and will externally rotate the shoulder.
  • Use slow and controlled movement, don’t rely on momentum.
  • Allow the arms to move freely but avoid locking out the elbows.