“This highly functional exercise not only works the core, it also challenges the important reactive process involved in core stability. It's amazing the sweat you can produce with this move because of the multiple muscle groups involved,” says Michele Olson, Ph.D., professor of exercise physiology at Auburn University.
How to do it: Stand sideways with your feet wider than shoulder-width apart and hold a weighted ball at about forehead level, arms bent 90-degrees and knees slightly bent. Then, as if you were going to hurl the ball down and behind you to the right, tighten your abs and rotate your body into a lunge-style stance, bending both knees until the back shin is parallel to the floor. Your arms will straighten with your hands traveling to the outside of your left knee. To reverse, tighten your abs and explode up through your legs, returning to the start position. Do 15 from left to right and another 15 from right to left.