The Hollow Body Position is a vital element in Calisthenics, as it will be the base for many other exercises.
1. Lay down on your back and tighten your abdominals. Make sure your lower back is touching the ground. The arms and legs need to be kept straight at all times and the toes of your feet need to be pointing.
2. Lift your shoulders and legs from the ground. The arms and head also need to lift from the ground following the shoulders. The lower back needs to remain in contact with the ground.