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Ab belts may cause muscle contractions if used properly. But the belt alone cannot produce six-pack abs. The real challenge to ab definition is the layer of fat that lies right under the skin, hiding muscle tone.
Crunches have been the mainstay of ab workouts for decades and, though we've found plenty of other exercises, crunches are still a great way to target your abs. Specifically, crunches target the rectus abdominis or what we usually call the '6-pack muscles' that run along the front of the torso.