The Sweeper exercise works your abs, butt and legs.

-Beach Body Now: Sweeper. As you swing your leg out to the side and in front of you, really squeeze your glutes and feel the burn. Try to remain in that bent, seated position keeping the weight on your stable leg, as you quickly return to the back lunge. Do 10 reps, switch sides, and repeat. Do 2 to 3 sets total.