Pick up a pair of dumbbells and sit at the end of a bench or chair and lean forward at the waist. We are going to be working both arms at the same time.
Now bend your arms and raise your elbow back and up – as far as your shoulders will allow. Keep your elbows fixed and close to your sides and let the dumbbells hang. Press the dumbbell back and hold for a second, flexing. Then slowly bring the dumbbells back down.