Begin in a plank position with your shoulders stacked above your wrists, and your body in a straight line between the top of your head and your heels. Lift your right leg and bend the knee 90-degrees, bringing your heel toward your butt. With a flexed foot, squeeze your glutes, and raise your right heel up toward the ceiling as high as you can. Pause, then bring your right knee back to meet your left knee to complete one rep