We've all seen them: perfectly toned celebrities on late-night television telling us that we too can develop rock-hard abdominal muscles. It's easy! Just slap down $149.99 for the Torso Track or $149.75 for the Ab-Doer and watch those unwanted inches melt from your waist. Americans shelled out tens of millions of dollars last year on various devices to firm up their flabby midriffs.
And did they work? Not necessarily. Independent studies have concluded that most of these products--no matter who endorses them or how expensive they are--shape your midsection no better than old-fashioned stomach crunches. Some can even cause injury--like the...