Mellalieu estimates that by participating in one session of Wii boxing, tennis or bowling, you can burn between 75 to 125 calories. In addition, a study by researchers at the Liverpool John Moores University in England found that "regular use of the console could burn up to 1,830 calories a per week -- the equivalent to almost four Big Macs." Wow.

So the next time you hear someone complain that working out is boring, just let them borrow your Wii.