title: [Step-test on surveillance of students' physical fitness and health].
abstract: OBJECTIVE
  To analyze the role of step-test on large sample surveillance in students' physical fitness and health.
  
  
  METHODS
  Totally, 36 237 students aged 12-, 14- and 17-year-old from fifteen Chinese provinces taking part in the 2004th National Surveillance on Students' Physical Fitness and Health were enrolled in this study. All of them passed through the step-test, of which the indices were calculated in combining with the performance time and pulse rates in resuming period. The means of step-test index were analyzed among various youth groups, and compared with the obesity, overweight and the normal-weight subjects.
  
  
  RESULTS
  As compared with the general level of physical growth, the means of step-test index were found higher in rural groups than in urban ones, and higher in southern groups than in northern ones. The highest means of index was found in the rural groups in having the lowest socioeconomic status, and also the lowest means found in metropolis groups having the highest socioeconomic status. These gaps were due to the change of life style, absence of physical exercise and relatively to the high body weight of the high socioeconomic-level groups. Among the obesity, overweight and normal-weight youths, the means of step-test index was shown in a gradient decrease tendency, and those significant gaps might be found between the obesity and the overweight, and the overweight and the normal-weight groups, showing that there should be harmful influences of overweight and obesity on the youth's cardiovascular function.
  
  
  CONCLUSIONS
  As a safe and easily-taken measure for cardiovascular function, the step-test should be useful in regularly measuring the national students' physical fitness and health status.
authors.affiliation: Institute of Child and Adolescent Health, Peking University, Beijing 100083, China.
authors.forename: Cheng-ye
authors.initials: CY
authors.lastname: Ji
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.forename: De-cai
authors.initials: DC
authors.lastname: Zhao
authors.forename: Pei-jin
authors.initials: PJ
authors.lastname: Hu
authors.forename: Yi
authors.initials: Y
authors.lastname: Xing
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000517:prevention & control*; D010809:Physical Fitness; D012424:Rural Population / Q000706:statistics & numerical data; D013334:Students / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data; D055815:Young Adult