Instead of calling it a “stability ball” perhaps we should call it a “belly ball” since scientists have shown that using a stability ball in conjunction with a cardiovascular workout can shed as much as an inch from your belly in as little as two weeks! The trick seems to be to alternate your workouts: one day of cardio, one day of the stability ball.

Stability balls can be purchased online or at a sporting goods store (or any store that sells fitness equipment). Most people need to use a twenty-two inch ball, but people less than 5’1″ should buy the eighteen inch ball and people over 5’8″ should purchase a twenty-six inch ball. You want to find a ball that is resistant to punctures and that, if it does get punctured, will deflate slowly (nothing is worse that being balanced one second and then falling flat on your backside the next). Stability balls typically cost around thirty dollars.

One of the best exercises to do with a “belly ball” is to lie down on the floor facing up. Rest your calves on the ball and, pushing your legs into the ball, squeeze it between your thighs and calves. Contract your abs and lift your hips from three to six inches off of the floor while you pull your knees in toward your chest, keeping hold of the ball. Hold that pose for at least one second and then lower your hips. Repeat this exercise for two minutes!

If you are very coordinated, you will love the “pike” exercise in which you start with the ball under your shins and your hands flat on the floor and roll it to the tops of your feet while lifting your hips so that your torso is as straight as possible, forming close to a ninety degree angle—almost like you are trying to do a handstand!