Split Squat Rotation...

Best for: Leg, glute, and arm strengthening 

Stand with feet together, holding a 5- to 10-lb medicine ball (you can also use a soccer ball or a stack of books) at chest. Step left foot back and lower into squat with right knee bent. Push into right leg, straightening both legs while twisting torso to push medicine ball over right shoulder; return to previous position. Continue for 30 seconds; switch sides and repeat.