Bring yourself to the ground and enter a high plank position with your hands directly under your shoulders and your feet directly behind you, resting on the top of an exercise ball. Keep your core braced and be sure not to the let your hips drop. With control, proceed to bend at the hips driving them upwards and towards your shoulders. Exhale as you do so. Make sure to keep your core contracted throughout. You should finish in an inverted V position. Pause and slowly return to the start position, inhaling as you do so.