"Maybe I should have bought that Abkajigger after all…"

RODALE NEWS, EMMAUS, PA—The airwaves are buzzing this time of year with miracle cures for paunchy bellies, whether it's the Ab Dolly, the Ab Lounge, the Ab Roller, Crunchless Abs videos, or any of the countless other "get six-pack abs in just 15 minutes a day" workout machines. Yet, anyone seriously dedicated to losing that spare tire or muffin top can simply get down on the floor to do some crunches to get the same results. Or can they? We asked Fabio Comana, MS, MA, an exercise physiologist with the American Council on Exercise, for his advice on the most effective ab exercises.

This: Ab Equipment
Pros: While there's very little science to back up the effectiveness of these machines, "they're not entirely ineffective," says Comana. "For one, they get a person started with exercise." The better-designed machines, he adds, target a variety of muscles, including the abdominals that'll give you the six-pack you want—your obliques (the side-ab muscles) as well as your lower-back muscles—and it's that balance of muscle strength, often neglected with floor exercises, that helps to prevent back injuries.

Cons: They can be expensive. Second, says Comana, they put you at risk of hitting a plateau. Muscles need increasing amounts of overload to make them stronger, and "when someone starts out with machines, there is that initial overload because their abs have been doing nothing. But eventually, your body adapts, and if you don't give it any further stimulus, you reach a plateau," he says.