Check out Women's Health's FitGIF Friday every week for fun and challenging new moves to make your sweat sesh really count. This week's exercise is courtesy of Furthermore:

Three-way medicine ball slams: Are you ready to throw down in this gym this weekend? Puns aside, this move delivers a total-body workout with extra emphasis on lengthening and strengthening your abs. And the simple form is nearly impossible to screw up—what more could you want? For the full circuit workout, check out this page on Furthermore. 

(Get more legs-sculpting workouts from Women's Health's Look Better Naked DVD.)

Three-Way Medicine Ball Slam
Furthermore

How to: Stand with feet shoulder-width apart, holding a medicine ball with both hands overhead. Slam the ball hard enough to bounce off the floor, then catch. Lift the ball overhead, pivot your body to left and repeat. Rotate back through center, lifting the ball overhead, and pivot to right; slam the ball to floor. Continue alternating from side to side, moving as quickly as possible, for 45 seconds.