"The first abdominal sculpting system that is designed to shed pounds and inches in just minutes a day," claims an infomercial for the $400 Ab Coaster.
We've seen other machines with similar claims, and like those, the Ab Coaster is not all that it seems.
Our electromyography tests, which measure muscle activity, found that the device activated abs as promised, but so did the simple, back-friendly McGill curl-up. A side-plank lift, another exercise you can do without equipment, provided greater oblique-muscle activity than the Ab Coaster's side lift.
The manufacturer claims that the product causes "virtually no stress or strain on your neck or back," but 16 percent of our testers reported lower-back discomfort when using it.
Any weight loss resulting from the Ab Coaster "system" would probably come from following the accompanying low-calorie diet, a two-week "express" plan, and performing the supplementary cardiovascular workout on the included 20-minute DVD, rather than the triweekly, 5-minute machine workout. Our nutrition experts thought the supplement-heavy diet, with some skimpy meals, would be difficult for many people.
The promotional materials claim that the machine is "so easy," but we found that only 20 of the 50 testers could consistently perform the exercises properly, even when our fitness expert intervened.
If buying the Ab Coaster inspires you to exercise and watch what you eat, the product could be helpful. But diet and some routine exercises can replicate the results, so your money—and floor space—can probably be put to better use.