The Exercise That Adds Muscle Mass to Your Rear Shoulders

Your posterior or rear deltoid is typically thought of as a shoulder muscle. But the exercises that work them best are the same ones that work your middle and upper back. That’s because your rear delt pulls your upper arm backward - just like a rowing exercise does. 

And the best row for your rear delt: the batwing, according to Men’s Health Fitness Director B.J. Gaddour.