Fitness fanatics are scuttling around on all fours, in a practice that has been dubbed 'quadrobics'. Advocates of quadrobics say it offers a 'full-body workout', with one even claiming they were able to achieve a six-pack within weeks. However, not everyone is so convinced. Some critics have warned of the potential injury risks associated with quadrobics, while others have gone so far as to claim that the exercise 'poses a danger to society'.
You may be surprised to learn that the treadmill was invented as a prison torture device in 19th-century England. Or maybe you're not surprised, depending on your feelings about huffing and puffing as you trod along on an automatic belt to nowhere. Still, it's a little wild to realize that upward of 50 million Americans willingly use a device each year that was conceptualized to make criminals suffer. A lot of people are gluttons for punishment, though.