Shaped like a household body scale with a white top and grey bottom, Wii Balance Board contains pressure sensors used to control the virtual movements. Also, the sensors are used to measure the user's center of mass and body mass index.

Since the product was released in Japan in December last year, Wii Fit has already sold 1.5 million copies, and is expected to do very well on the US  market.

Wii Fit includes more than 40 types of training activities which fall into four fitness categories: Aerobic Exercise: 10-minute exercises that are designed to get the heart pumping, Muscle Conditioning: Controlled motions using arms, legs and other body parts, Yoga Poses: Classic poses that focus on balance and stretching, and Balance Games: Fun activities, such as ski jumping and heading soccer balls, which challenge the player’s overall body balance.

In Japan it has been encouraging family members as a whole to discuss the topic of fitness and take an active interest in understanding their own fitness in a fun and entertaining way, all in the comfort of their own home, Nintendo said.

Wii Fit allows up to 8 people to track progress and monitor performance. Once you insert the Wii Fit Disc into a Wii console, a new channel - Wii Fit Channel can be added to your Wii Menu system.

Once the Wii Fit Channel is added it enables users to not have to insert the Wii Fit Disc into a Wii console in order for the Wii Balance Board to scale your weight to calculate your BMI, measure the center of your bodily balance and conduct a balance test in order to calculate your Wii Fit Age.

It also allows you to monitor how long you did which category of exercise for in one day, all in the comfort of your own home and without the need to keep inserting the Wii Fit Disk into your Wii console each time.

Wii Fit will receive the largest marketing launch in Nintendo’s history. Wedbush Morgan Securities analyst Michael Pachter predicted that Wii Fit will sell 3 to 4 million units in the US.