Rear Delt Fly

The forgotten third of your shoulder — small muscle, big posture payoff.

Rear Delts, Upper BackDumbbellsBeginner
Animated form guide for the rear delt fly — two-pose loop with the rear delts, upper back highlighted
Worked muscles are highlighted. Loop runs continuously — rear delt fly, start to finish.

Setup

  1. Hinge to near-flat back, light bells hanging, slight elbow bend.

How To Do It

  1. Raise the bells out wide like spreading wings.
  2. Squeeze the rear shoulders at the top.
  3. Lower with control.

Breathing

Exhale on the raise.

Common Mistakes

  • Heaving with the torso — the hinge is frozen.
  • Too heavy — this muscle is small; train it like it.
Coach Sam's cue: Wings out, thumbs down slightly.

Programming It

Three sets of 12-20. Light.

Why This Exercise Works

Rear delts are behind you, so nobody trains them until a coach points it out. They also oppose everything you do at a desk and everything you do on a bench, which is why adding two easy sets a week changes how the shoulder feels within a month.

Where You Should Feel It

The back of the shoulders, small and specific. Rear delts are behind you so nobody trains them until told to, and they oppose everything a bench press and a desk do.

Where It Fits in a Program

The forgotten third of your shoulder — small muscle, big posture payoff. Put it late. Nothing here needs you fresh, and the reps are cheap to recover from.

Progressing and Regressing It

To progress the rear delt fly: add reps and a one-second hold before adding load. To regress it: support the chest on an incline and reduce the load further.

Who It's For

Everyone with a pressing-heavy programme. Two easy sets a week changes how the shoulder feels within a month.

Equipment and Substitutions

This version uses dumbbells. No dumbbells? A kettlebell of similar weight works for almost all of this, and the cable and machine versions below cover the rest.

Related Exercises

Common Questions

What muscles does the rear delt fly work?

The rear delt fly primarily trains the rear delts, upper back.

How many sets and reps should I do?

Three sets of 12-20. Light.

What are the most common rear delt fly mistakes?

Most often: heaving with the torso; too heavy.

Do I need dumbbells to do this?

This version uses dumbbells, and it trains the rear delts, upper back. Kettlebells substitute directly here. So does a cable, if you would rather have constant tension than a free weight.

Is this safe if I have an existing injury?

The rear delt fly puts the shoulder and elbow under load through a range many people have lost, so a cranky shoulder usually objects here before anything else does. Pain that pinches at a specific point is worth assessing; ordinary training discomfort is not. Not medical advice.

Form guide for educational purposes — not medical advice. New to training or working around an issue? Apply for coaching and get a plan built for your body.

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