Long-term change trend of cross age among pupils and middle school students in Anhui province from 1985 to 2005

Objective To study the long-term changing trends of pubertal growth spurt of adolescents in Anhui from 1985 to 2005.Methods To describe the cross chart of height and weight,combine its'increase rate from 7 to 18 years old students in Anhui province by using the data from the Physical Fitness and Health Surveillance of Chinese School Students in 1985,1990,1995,2000 and 2005.Results It was shown that from 1985 to 2005 the cross age of height and weight in adolescent shifted ahead and the cross interval reduced and narrowed gradually.The max of height extent decreased from 2.635 cm in 1985 to 1.656 cm in 2005.The max of weight extent decrease from 1.605 kg in 1985 to 1.521 kg in 2005.Conclusion The growth spurt among boys was higher than among girls from 1985 to 2005,which causes the cross age space decreased.