Start in a standard high plank position with your wrists directly underneath your shoulders and your fingers pointing forward. Your back should be flat and in a neutral position; there shouldn't be any arching or rounding of your spine.
Without shifting your hips, lift your right foot off of the ground and drive your knee toward your left elbow or as far as you can go.
Hold for 30 second and then repeat for 30 seconds on the left side.