Rear Delt W Fly
Sit on the front of a bench with a dumbbell in each hand, and bend forward until the trunk is at a 45-degree angle or lower.
Raise the dumbbells to the sides while bending the elbows and rotating the hands back, trying to create a W shape at the top, then lower under control.
Purpose
The rear delt W fly trains the posterior and lateral delts as well as most of the upper back musculature to a lesser degree. Unlike a conventional rear delt fly, the W fly adds the external rotation function.
Programming
Generally 10-20 reps are appropriate. Weights will typically be much lighter than expected because of the relative weakness of the posterior delts.