HOW: Begin in an all fours position. From here, push up onto your toes into a bear plank position. With a strong core, kick one leg behind you, return to the starting position, and switch legs.
FEEL: You should feel your core, shoulder and leg muscles working. Your gluteal muscles will work as you extend your leg behind you.
COMPENSATION: Avoid allowing your hips to rotate as you do this exercise. Keep your core engaged and work through a smaller more controlled motion if you notice excessive rocking of your hips.