Chinese children have grown taller and heavier in recent years but their health is getting worse, a senior education official said on Wednesday, criticising pressure from parents and teachers to study.

A pupil raises his hand to answer questions at a class in Jiaxing, east China's Zhejiang Province, in this photo taken on April 6, 2005. [Newsphoto/file]

"The inappropriate educational concepts, which put study ahead of anything else and impose great burden on pupils, have seriously affected their healthy growth," said Liao Wenke, an official in charge of youth development.

"The endurance, strength and lung capacity of the children continue to fall - and rapidly, especially in the last 10 years," Liao told a news conference.

The average height of children aged seven to 18 had increased by up to 1 cm in 2005 from 2000, and the average weight had also risen - but the performance in sports had declined.

"Obese schoolchildren are increasing in numbers swiftly, and the percentage of myopia remains high," he said.

China now has the world's second highest myopia rate among schoolchildren, blamed in part on too much study, and obesity among the young has become a major health concern.

Chinese parents and teachers pressure children to succeed at an early age, with holidays and leisure time often sacrificed for homework to ensure success in college entrance exams.

The education ministry had urged schools nationwide to pay more attention to sports and lighten children's burden by reducing homework and increasing exercise, Liao said.

President Hu Jintao also emphasised the importance of sports for children this week, urging local governments to use "healthy competition" to shape Chinese youth.