People spend millions of dollars annually on exercise machines and products that are promoted as quick-fix solutions to achieving washboard abs. The real question, however, is how do those products measure up to the traditional crunch?

In keeping with its role as America's Workout Watchdog, the American Council on Exercise (ACE) commissioned exclusive research from experts at the University of Wisconsin, La Crosse to evaluate the effectiveness of the most popular equipment and exercises compared to the traditional crunch.

"We spent a considerable amount of money on abdominal exercise equipment to basically show that you can effectively train the abs at home for free," said Edward Stenger, M.S., who led the research team alongside John Porcari, Ph.D. "Everything else is arguably a waste of money from this standpoint."

The team incorporated popular equipment including the Ab Circle Pro, Ab Roller, Ab Lounge, Perfect Sit-Up, Ab Coaster, Ab Rocket, Ab Wheel and Ab Straps, as well as exercises including the yoga boat pose, stability ball crunch, decline bench curl-up, captain's chair crunch, bicycle crunch, side plank and front plank.

Electromyography (EMG) was used to identify a baseline of abdominal strength among all participants (eight males and eight females, ages 18-24). Electrodes placed on the upper and lower rectus abdominis (URA and LRA), external obliques (EO) and the rectus femoris (RF) measured subjects' maximum voluntary contraction (MVC) as they used each piece of equipment and performed each bodyweight exercise.

The result was that none of the moves elicited greater muscle activation than the traditional crunch. The Ab Wheel, Ab Circle Pro, side plank and front plank all had significantly lower muscle activation in the URA compared to the traditional crunch. And for the LRA, the Ab Circle Pro, side plank and front plank also all had significantly lower muscle activation than the crunch.

"Obviously, lying on the ground doing the traditional crunch is not appropriate for everyone," Stenger said. "But for the average person who wants to work his or her abdominal muscles to get stronger, have less back pain and get better health benefits, all you need to do is get a comfortable spot on the floor, lie down and do some crunches."

Regardless of the results, ACE Chief Science Officer Cedric X. Bryant, Ph.D., said, "It's important to keep in mind that there is no single abdominal exercise that challenges all the abdominal muscles in the safest and most effective way. For example, some exercises like the planks help to promote the development of core stability despite their relatively modest levels of muscle activation in the muscles examined in this study."