Games consoles and fitness have never really mixed well.
Expensive gyms have tried to link running machines and bikes with computer displays for years. Even Sony tried to cash in with an easily forgotten Playstation game called Kinetic.
So Nintendo is taking a bit of a gamble with its new Wii add-on.
Wii Fit is a £70 set of plastic weighing scales. Four pressure sensors in the "balance board" measure your centre of gravity and body mass index.
Before you start training, the game lets you pick an instructor and calculates your body mass index. You can set weight loss goals over weeks or months.
BBC Radio 1's Scott Mills can be seen in our video giving it a whirl.
And Sharon Irvin, 28, has been testing the game for Newsbeat.
'Easy to use'
She said: "I've been trying to lose weight for 20 years. I've tried diet classes, exercise classes and gyms. I'm looking for something that will finally get me fit.
"Sometimes I just can't be bothered to go to the gym. I'd rather use something like the Wii for 15 minutes every day rather than make the decision to go training.
"Game consoles are so advanced these days, they can put people off. But the Wii is easy to use.
"I thought I would get bored really quickly, but the games are well designed so you keep progressing every day."
Training is split into four main areas: aerobic exercise, muscle conditioning, yoga and balance games.
In the step class, you jump on and off the board in time to the background music.
Yoga forces you to bend your body into position while the board measures your centre of gravity.
Less sporty, but more fun, are balance games like hula hooping and snowboarding.
Other games don't use the board. One makes you jog on the spot with the standard Wiimote stuffed in your pocket.
Sharon reckons she worked up a sweat using the game. But she doesn't think you can compare it to regular exercise.
She said: "It's more of an introduction to training for someone who wouldn't normally go to the gym. You do run the risk of feeling you have done your day's exercise after 15 minutes."
Charlene Shoneye is the obesity dietician at the charity Weight Concern.
She said although it is likely to burn off more calories than sitting down and playing a computer game, losing weight through exercise alone is almost impossible.
"Unfortunately the amount we burn up through exercise isn't as much as we think it is," she said. "I doubt a game console in itself is likely to have much of an effect on weight.
"One of the concerns we have is the name - Wii Fit. For some people it may imply it has a dramatic effect on their fitness. I don't see this replacing the more vigorous physical activity like sport or the gym."
Wii Fit beat records when it went on sale in Japan last year. Two million sets have already been sold in Asia.
Gamers in Europe can get hold of the board from 25 April with North America following on 19 May.