Play.com has sold out of its entire allocation of Wii Fit in just one day, ahead of the games official release on April 25 in the UK.
Pre-order demand has "overwhelmed" the online retailer, following success in Japan that saw the game sell one million copies in just over a month on sale.
"People continually look for new and fun ways to stay in shape and it’s fantastic to see exergames in big demand," commented Gian Luzo, head of games at Play.com.
"Wii Fit is going to be huge – let’s hope that we can keep up with demand. We are expecting more stock before launch," he added.