Bring yourself to the ground and enter a high plank position with your hands directly under your shoulders and your feet directly behind you. Carefully, insert one foot at a time into hanging TRX straps. With both feet securely in the straps in a high plank position, proceed to bend your knees and bring them towards one side. Exhale as you do so. Make sure to keep your core contracted throughout. Pause at the top of the movement and slowly return to the start position, inhaling as you do so. Repeat the same movement on the other side; bringing your knees towards the opposite side. Keep alternating sides for the required number of reps or time.