Stand or sit holding a dumbbell in each hand and hinge slightly at the hips with a neutral spine. Begin with arms down and palms facing each other. As you lift the weights outward and upward, rotate your shoulders so your palms end facing slightly back. Focus on squeezing the muscles between your shoulder blades and controlling both the lifting and lowering phases to build strength and stability in the rear shoulders and upper back.
Log your dumbbell rotation reverse fly sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.