The 3 most effective ab workouts, according to experts

Shutterstock According to a study done by the American Council on Exercise, there are three abdominal workouts that are most effective in achieving a strong core and washboard stomach muscles. Bicycle crunches use all of the abdominal muscles, including the rectus abdominis — the front ab muscles that make up the visible six-pack. The captain's chair stimulates both the abdominals and the obliques that line the sides of your abs. Finally, crunches done on a medicine or balance ball will engage...