46. Kick Boxing
Kick boxing is awesome for a variety of reasons. You get your heart going, so there's your cardio. The best part is that you're working your entire body. It's fun, intense, and extremely helpful in working off a muffin top. Plus you'll look ripped in the bargain! Ask around about possible kick boxing classes, or see if your gym or YMCA offers any classes. Take a friend with you while you're at it -- the two of you can learn together!