I've tried the soccer headbutt-game and hula hoop. I kept missing the ball. the hula hoop really made me exercise...!

Tip: Remember the receiver is on the board, I kept moving my head. Then saw the eg. pic at the bottom and found that it was sensing the movement of your body weight. baka!

I can see it being a nice end-of-day habit for me (with the body-flexing, etc...), since I'm stuck at the office desk too much.
Don't expect becoming Hulk in 3 days tough, unless you're going the buy 2 boards for weightlifting~

I'm sure there are more conventional ways to exercise. Fit just makes it fun and records the progress for you to see, so I guess it's a great thing for making kids into it too.
Note: Since you're standing for the game, the height the tv is placed is a cause of concern (especially if you're gaming room is really small).