Aerobic exercise (or just dance, it's fun!)

Good news! You don't have to kill yourself with crunches to get a sleek stomach. But it turns out that you do need to get your heart rate up. Aerobic exercise is key to banishing both the deep belly fat and the superficial doughy stuff that give you a pooch. How much aerobic exercise does it take to trim a tummy? In a recent study, overweight people who jogged, cycled, or hit the elliptical for about 3 hours a week had the best belly-busting outcome -- as long as they exercised at an up-tempo pace. Not ready to go that distance yet? Try walking briskly for just a couple of hours per week. That's enough to at least keep belly swelling in check.