(1.Foundation School,Guangzhou Medical University,Guangzhou 510182,China;2.Sports Science and Community Health Care Sestem,University of Illinois at Urbana-Champaign,Urbana IL61801,USA) Abstract: In order to clarify dose-effect relations between medium and high intensity physical activities and obe-sity, hypertension, dyslipidemia and metabolic syndrome of teenagers, so as to determine medium and high intensity physical activity doses recommended for preventing cardiometabolic health risks of teenagers, the authors selected 3162 aged 12~17 teenagers in US Health and Nutrition Survey in 200—2004 and 2005—2006 as their research sub-jects, measured the height, weight, waist circumference, blood pressure, blood sugar, blood fat, food intake and physical activity levels of the testees, used the fractional polynomial model to respectively analyze the relations be-tween medium and high intensity physical activity times and cardiometabolic health risks (obesity risk, hypertension risk, dyslipidemia risk and metabolic syndrome risk), worked out their dose-effect curves by fitting, and revealed the following findings: there were dose-effect relations between medium and high intensity physical activity times and obesity risk, hypertension risk, low and high density lipoprotein risks, high triglyceride risk and metabolic syndrome risk of teenagers; these cardiometabolic health risks tended to decrease in a curvilinear manner as daily medium and high intensity physical activity times increased. Key words: sports medicine;physical activity;cardiometabolic health;dose effect;teenagers |