Gamers across North America and Europe are doing gentle warm-up laps of their living rooms in anticipation for the athletic event of the year. No, it’s not the Olympics but the release of Wii Fit on the 25th of April. The game has seen huge success in Japan, with sales of over 1 million since its December ‘07 release, and the expectation has been that things can only get better in the west.

It seems the game is well on track to fulfilling all expectations. Play.com today announced that they received an overwhelming number of pre-orders and sold out of the game in a single day. Head of games at Play.com, Gian Luzo commented, “People continually look for new and fun ways to stay in shape and it’s fantastic to see exergames in big demand.” Play.com are hoping for more stock of the game before release.

They’re not the only retailer feeling the pressure of such high demand. Earlier in the week GAME.co.uk plastered their website with notices stating they may not be able to fulfil pre-orders made after the 4th of April.

Though it’s early days for this “exergame”, there is the added production strain of its weighing scale-esque peripheral. It has already proven to be quite a rarity and Japan and unless Nintendo buck their ideas up they may find that it suffers from Wii-itus and is forever out of stock.