TRX Rear Delt Fly
"This works the same area as the rear delt raise but also hits more upper back muscles," says Ballantyne.
The Setup: Grab the TRX straps and take two steps backward. Lean back, so your arms are extended in front of you.
How to Do It: Squeeze the muscles between your shoulder blades and spread your arms out to the side while pulling your body to an upright position. Slowly return to the start position.