what does rear delt fly work

Rear delt fly primarily works the rear delts — the back part of your shoulders — and also hits the rhomboids and traps in your upper back. It’s mainly a pull movement and helps improve shoulder balance, posture, and upper-back stability.

Main muscles worked

• Posterior deltoids : the primary target.

• Rhomboids : help retract the shoulder blades.

• Trapezius : assists with shoulder and scapular stability.

• Rotator cuff muscles like the infraspinatus and teres minor can also assist, especially in stabilization.

What it’s good for

• Building the back of the shoulders.

• Improving posture by strengthening muscles that pull the shoulders back.

• Supporting shoulder health and stability during other lifts.

Quick tip

If you feel it mostly in your traps, the weight may be too heavy or your form may be turning it into a shrug. Keeping the movement controlled usually shifts the work back to the rear delts.

If you want, I can also give you the best form cues for rear delt flys in 5 bullets.