In an effort to be more environment friendly, organizers of this summer's Tokyo Olympicshave built cardboard beds for the athletes to sleep on.Some observers have questioned whether such beds will be strong enoughto hold some of the heavier Olympic competitors.But Takashi Kitajima, who is in charge of the athletes' housing for the event,told The Associated Press he is not worried about any beds breaking."Those beds can stand up to 200 kilograms," he said.Kitajima added that the cardboard beds were made to be even stronger than wooden beds.However, he did say there could be a problem if some athletes get too excitedcelebrating their gold-medal success."Of course, wood and cardboard would each break if you jumped on them," Kitajima said.The Athletes Village housing center is expected to be completed in June.The Olympics are set to open in Tokyo on July 24.Japanese officials say the cardboard bed parts will be recycled into paper products after the games.The mattresses are not made of cardboard.But, they can be recycled into plastic products.The mattresses are made up of three separate parts.This will permit the athletes to change positions to create the best sleep experience possible.Kitajima said, "The organizing committee was thinking about recyclable items,and the bed was one of the ideas."Organizers said it is the first time for Olympic bedding to be made out of renewable materials.The Athletes Village is set along Tokyo Bay.It will include 18,000 beds for the Olympics in 21 separate buildings.Local advertising has suggested that the units will be sold off after the Olympics.Starting prices for the housing were listed at about $500,000.Some locals fear the apartments will flood the market and reduce their property values.The listings suggested that many of the units will be a bit largerthan a usual living space in Tokyo, which is about 60 to 70 square meters.