Sit on an upright chair that has a back support, holding a dumbbell in each hand with an overhand grip and with both feet firmly on the floor. Raise the dumbbells upto your shoulders, level with your ears, with the palms of your hands facing forwards and your elbows in line with your shoulders. This is the start position. As you exhale, push the dumbbells up and directly over your head by extending your arms until the dumbbells almost meet at the top of the movement. Think about initiating the push from your elbows as opposed to your hands. Slowly return to the start position inhaling as you do so. Repeat for the required number of reps (or time).