The overweight rate among Chinese urban teenagers is 13.25 percent for boys and 8.72 percent for girls.

Apart from obesity, Chinese students face other physical problems like short-sightedness and high blood pressure, and their stamina, speed, vital capacity and strength are decreasing, the survey said.

Statistics also showed that 20.9 percent of parents are not in favour of physical exercise for their children and 66 percent of students exercise for less than an hour everyday.

Zhong, who was a national 400 meters hurdles champion and still holds several track and field records of the Medical School of Peking University (formerly the Beijing Medical University), said that competitive sports are the best way for the youngsters to improve their health.

"I am 71 years old and am still energetic. I should thank sports to make me so fit. I began to take part in competitive sports when I was in primary school. And sports have always been a part of my life since then."

Zhong has been playing basketball twice a week since 1983 and without sports, he can never hold on as a doctor. "I worked for 40 hours without any rest during the SARS outbreak in 2003 and lost five kilograms of weight. I should thank sports most."

Editor:Du Xiaodan