HOW: Start this exercise on your back in a 90/90 position, with your knees over your hips and your arms in front of your shoulders. Keep the small of your back pushed into the floor by activating your core. While maintaining core activation drop one leg and the opposite arm towards the floor. The closer you drop the arms and legs towards the floor the more challenging this exercise will be. Return to starting position and repeat on the opposite side.
FEEL: You should feel the abdominal muscles engaging while you perform this exercise.