"Those beds can stand up to 200 kilograms,"explained Takashi Kitajima,the general manager of the Athletes Village,speaking through an interpreter.
Surely no Olympic athlete weighs that much.
"They are stronger than wooden beds,"Kitajima added.
He also took into account the possibility of a wild room celebration after,say,a gold-medal victory.
"Of course,wood and cardboard would each break if you jumped on them,"he said.
The single bed frames will be recycled into paper products after the games. The mattress components - the mattresses are not made of cardboard - will be recycled into plastic products.
The mattress is broken up into three distinct sections,and the firmness of each can be adjusted.