Bent Over Rear Delt Fly

The bent over rear delt fly is the standard isolation exercise for the posterior deltoid, the head of the shoulder that almost no programme trains directly. Hinged forward with the torso close to parallel to the floor, you raise the dumbbells out to the sides until the arms reach shoulder height, letting gravity pull the weight straight down so the rear delt is the only muscle that can lift it. That torso angle is what makes the exercise work. If you stand up as the set gets hard, the load shifts to the lateral deltoid and the movement stops doing its job. A slight, fixed bend in the elbows keeps it a fly rather than a triceps extension. Use modest weight, because the rear delt is small and responds far better to a clean path than to loads that force you to heave with the back.