The Beijing education authority's directive that school students exercise for an hour each day during the coming summer vacation to ensure good health may fail to have much effect, despite a 20 percent obesity rate among the city's school children.

"Given how little importance parents attach to physical exercise nowadays, I'm not optimistic kids will come back to school stronger and healthier after two months' vacation," said Wang Bao, a physical education teacher in Beijing's Chaoyang district.

Most parents, especially those of primary school students, pay little attention to the physical condition of their children, he said.