This kickboxing move not only shapes up your glutes, thighs, and hips, it also helps flatten your belly!
How to do it: Stand with arms bent, hands in fists by your chin. Rotate your left heel in towards your body and shift weight to your left foot. Bend your right knee, flexing foot, and lift your leg up to hip height. Extend your lifted leg out to the side, as if pushing something away from your body with your heel. Bend your knee back in (try not to lower your leg in between repetitions if possible). That's one rep. Do up to 3 sets of 15 reps on each leg, switching sides after each set. Need help balancing? Try lowering your leg for the kick and/or lightly holding onto a chair or the wall.
Also try: Side kick plank, kneeling roundhouse kicks.