STARTING POSITION:
Select the appropriate weight of the dumbbells. Lie on a flat bench. If is not, adjust the bench to get it. Move your arms to hold the dumbbells just above you with your elbows slightly bent and the palms looking at each other. Contract your pelvic floor and core. Make sure your feet are flat on the floor (or on the bench) and your head rest on the bench.
MOVEMENT:
Start lowering your arms to the sides until they are paralell to the floor preventing the elbows from bending. Inhale during the descent. Return to the starting position in a strong movement while you exhale.
TIPS: While your are doing the exercise, move only the shoulder joint, make sure you don't move any other part of your body. During the descent, focus on slow and controlled movement.