Stand an arm's length from a chair or countertop, with your feet hip-width apart, toes pointing forward. Fold forward at your hips to make an L shape with your body, placing your hands on the surface in front of you.
Soften your knees, and pull your abs in. Lift one leg to seat height (as shown), then bend your knee in half, flexing your foot.
Keeping your chest in line with the top of the chair or counter, quickly lift your leg upward about an inch for 20 reps. Next, do the same movement at a slower pace for 10 reps.
Repeat this circuit five times before switching legs.