Shoulder Press Arm Exercise
1. Get into the normal press up position.
2. Move your hands and feet closer together so your body forms a V-shape.
3. Raise and lower yourself, you should feet the emphasis on your shoulders and triceps.
To make the exercise harder you can put your feet on a high object (as shown below) or put a few books under each hand so you can go lower into the exercise and have a fuller range of movement.