Grab a set of dumbbells and start by lying on your back on a bench.
With one dumbbell in each hand, raise your arms so they are above your chest, making sure your elbows are straight but not locked.
Slowly lower both arms toward your head, bending your elbows at 90 degrees as the dumbbells reach the mat. Aim to lower your dumbbells so they are on either side of your head, elbows bent and pressing in toward your head.
Lift arms back up to starting position.