This power move works the core, shoulders, upper back, biceps and triceps. And thanks to the positioning, it also forces the body to use the stabilizing muscles of the core, which tones your abs and promotes good posture.
Assume the push-up position with the feet shoulder-width apart, gripping a dumbbell in each hand. Keeping your back flat, pull the right dumbbell up towards your torso, elbow tucked close to you side. Control the dumbbell back to the ground, and repeat on the left side.