Exercise Profile
  • Target Muscle Group
  • Exercise TypeStrength
  • Equipment RequiredDumbbell
  • MechanicsIsolation
  • Force TypePull (Unilateral)
  • Experience LevelBeginner
  • Secondary Muscles
    Traps, Triceps
Target Muscle Group


Shoulders Muscle Anatomy Diagram

Side Lying Rear Delt Fly Overview

The side lying rear delt fly is a shoulder exercise used to target the rear delts.

It is a great unilateral exercise to use to target a smaller and often lagging muscle group.

Side Lying Rear Delt Fly Instructions

  1. Secure a flat bench and select the desired weight from the rack.
  2. Hold one dumbbell directly in front of you while side lying against the bench. Use your free hand to support your head and bend your knees slightly to allow the bench to support your weight.
  3. Take a deep breath and pull the dumbbell towards the ceiling using the rear deltoid.
  4. Slowly lower the dumbbell back to the starting position under control.
  5. Repeat for the desired number of repetitions.

Side Lying Rear Delt Fly Tips

  1. Ideally we want to focus on the rear deltoids, not the scapular retractors so movement at the shoulder blade should be limited. Move the shoulder within the joint, not the shoulder blade on the ribcage.
  2. Keep the abs braced and don’t arch the back at the top of the movement.
  3. If you can’t hinge to 90 degrees, then hinge as far as comfortably possible while completing the exercise. Or, you could also take a seated position to complete the exercise as well.
  4. If you experience shoulder pain during the movement then it may be beneficial to rotate the dumbbells until the thumbs are pointing away from one another and the palms are facing forward. This is also known as a supinated grip and will externally rotate the shoulder.
  5. Don’t jut your head forward during the movement - this is about stimulation for a small muscle group. Focus during the movement and don’t just rely on momentum.
  6. Allow the arms to move freely but don’t lock out the elbows.