A round-up of the most ridiculous fitness gadgets in recent memory.

Ab Rocker & Ab Roller:

In a study sponsored by the American Council on Exercise, researchers at San Diego State University ranked 13 of the most common abdominal exercises.

And what did they find?

For one, they discovered that the Ab Rocker was the least effective of all methods tested; actually 80 percent less effective than a good, old-fashioned traditional crunch. Though it promised great results and a less p...