Performing the: A Step-by-Step Tutorial Dumbbell One Arm Hammer Press on Exercise Ball
Slowly roll down the ball until your upper back and shoulders are resting on the ball, your knees are bent at a 90-degree angle, and your body forms a bridge from your knees to your head.
Hold the dumbbell in your hand with a hammer grip (palm facing inwards towards your body), and extend your arm straight up towards the ceiling.
Slowly lower the dumbbell down to your chest by bending your elbow, keeping your arm close to your body.
Push the dumbbell back up to the starting position, fully extending your arm but not locking your elbow, then repeat the movement for the desired number of repetitions before switching to the other arm.