Exercise guide
Dumbbell Single Arm Reverse Fly Rack Support
- Intermediate
- Compound
- Rep-based
- Back
- Shoulders
This unilateral variation isolates the posterior deltoid and middle trapezius by using a power rack for stability, minimizing momentum and allowing for a deeper mind-muscle connection.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Stand sideways to a power rack and hold a dumbbell in your outer hand with a neutral grip.
- Hinge at the hips until your torso is nearly parallel to the floor, keeping your back flat.
- Place your non-working hand firmly against the rack at shoulder height to stabilize your torso.
- Let the dumbbell hang straight down with a slight bend in the elbow and your palm facing your midline.
How to do it
- Exhale as you raise the dumbbell out to the side in a wide arc, keeping the elbow fixed in a slight bend.
- Continue the movement until your arm is level with your shoulder, focusing on pulling with the back of the shoulder.
- Pause for a split second at the peak of the movement to maximize the contraction in the rear deltoid.
- Inhale as you slowly lower the dumbbell back to the starting position using a controlled 2-second tempo.
Form checklist
- Keep your torso stationary and avoid rotating your chest away from the floor.
- Lead the movement with your elbow and the back of your hand, not the dumbbell.
- Maintain a neutral spine by looking at a spot on the floor about two feet in front of you.
- Ensure the movement occurs only at the shoulder joint; do not increase the bend in your elbow.
Pro tips
- Think about pushing the weight 'out' toward the side wall rather than 'up' to better engage the posterior deltoid.
- Minimize trap involvement by keeping your shoulder blade depressed and avoiding a shrugging motion during the lift.
Make it harder
- Add a 2-second isometric hold at the top of each rep to increase time under tension.
- Use a 'pinky-up' grip (slight internal rotation) to further emphasize the posterior fibers of the deltoid.
Frequently asked
- What muscles does the dumbbell single arm reverse fly rack support work?
- The dumbbell single arm reverse fly rack support primarily targets the deltoids, and also works the rhomboids as secondary muscles.
- What equipment do you need for the dumbbell single arm reverse fly rack support?
- The dumbbell single arm reverse fly rack support uses dumbbell.
- Is the dumbbell single arm reverse fly rack support good for beginners?
- The dumbbell single arm reverse fly rack support is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.