（1.School of Life Science and Material Chemistry，College of Science & Technology Ningbo University，Ningbo 315300，China；2.School of Economics and Management，Shanghai Institute of Technology，Shanghai 201418，China；3.School of Physical Education & Health，East China Normal University，Shanghai 200241，China；4.Department of Physical Education，Shanghai Institute of Technology，Shanghai 201418，China)
Abstract: The authors analyzed the similarities and differences, changing patterns and distribution characteristics with respect to the body mass index (BMI) and cardiorespiratory fitness (CRF) of Tibetan and Han children and teenagers, so as to probe into the relationship between the BMI and CRF of Tibetan and Han children and teenagers. By using the random case method, the authors sampled 4 443 Tibetan and Han children and teenagers aged 7~18 in China (Han nationality: 2 400, Tibetan nationality: 2 043) as the research objects, evaluated their height, weight and 20m shuttling run (SRT), used the LMS method to establish the main SD distribution values of BMI and the main percentile distribution characteristics of Tibetan and Han children and teenagers, and used linear regression to probed into the relationship between the BMI-Z and 20m SRT-Z scores of Tibetan and Han children and teenagers. Results: before the age of 15, the 20m SRT scores at P50 of Tibetan boys and girls were lower than those of Han boys and girls, after the age of 15, the 20m SRT scores at P3, P50 and P97 of Tibetan boys and girls were all higher than those of Han boys and girls; the 20m SRT scores of Tibetan and Han children and teenagers with a normal weight were higher than those of overweigh or obesity children. The range of BMI-Z scores of Tibetan Han children and teenagers was -3.0~ 8.0; except Tibetan boys, the differences in the 20m SRT-Z scores of other different BMI-Z groups were statistically significant (P<0.05). Together with BMI-Z scores, the 20m SRT-Z scores of Tibetan chil-dren and teenagers increased first and then decreased; when BMI-Z scores were relatively high or low, 20m SRT-Z scores were relatively low. Conclusions: the CRF of Tibetan children was lower than that of Han children before the age of 15, but higher than that of Han children after the age of 15. The CRF of Tibetan and Han children and teen-agers with a normal weight was higher than that of overweigh or obesity children, and there was a roughly “para-bolic” changing relationship between the BMI and CRF of Tibetan and Han children and teenagers.
Key words: physical health；BMI；cardiorespiratory fitness；children and teenagers；Tibetan nationality；Han nationality