Rear delt fly

What it is

A movement in which you take the arms out and back against resistance from dumbbells, cables or a reverse pec-deck machine. It isolates the posterior deltoid, which pressing does nothing for and which most people carry as a visible weak point.

Muscles worked

Primary: Rear deltoids. Secondary: Mid-back (rhomboids, traps), Mid-back, Rotator cuff.

How to perform it

1. Hinge forward with light dumbbells hanging below you, or sit facing into a reverse pec-deck machine.
2. Set the shoulder blades and keep a slight fixed bend at the elbows.
3. Raise the arms out and back in a wide arc until they are roughly in line with your shoulders.
4. Lower under control without letting the weight swing back to the start.

Common form faults

• Going too heavy and turning it into a row. Light weight, wide arc, elbows fixed. If the elbows are bending, you are rowing.
• Shrugging the shoulders towards the ears. Keep the shoulder blades down and think about moving the upper arms, not lifting the shoulders.
• Swinging the torso to start each rep. Brace, or use a chest-supported or machine version so the torso cannot help.

Programming

A shoulder and upper-back accessory in higher reps. It responds well to volume and poorly to heavy loading, so treat it as a set you take close to failure with a manageable weight.