title: Short-term Effects of a Physical Activity Intervention on Obesity and Aerobic Fitness of Adolescent Girls.
abstract: BACKGROUND
  In the past two decades, physical activity has decreased during both childhood and adolescence, and particularly adolescence. It seems that schools are attractive settings in which to implement interventions designed in order to promote physical activity in children; but in Iranian students, few studies have evaluated the effects of such interventions on overweight and obese children. The aim of this study was to evaluate the effects of a short-term school-based physical activity on obesity and aerobic fitness in 12-14 years aged girls.
  
  
  METHODS
  This is a study with single group pretest and posttest design, in which 129 middle school girls in city of Isfahan were assessed based on preventive plan of inactivity in children at the Provincial Health Office. Variables, including weight, height, body mass index (BMI), waist-hip ratio (WHR), body fat percentage and aerobic power of subjects were measured using valid tests.
  
  
  RESULTS
  This study showed that subjects' body fat percentage changed about 3.6% (37.74% pretest vs. 36.39% posttest), VO2 max changed 7.43% (29.72 pretest vs. 31.93 posttest), WHR changed 1.12% (0.89 pretest vs. 0.88 posttest), whereas BMI was changed 1.65% (27.80 pretest vs. 27.34 posttest). Findings also revealed that there were significant differences between fat percent, (P = 0.001) and VO2 max (P = 0.001) of subjects, but there was no difference between BMI of them in pre- and post-tests (P = 0.361).
  
  
  CONCLUSIONS
  These results suggest that even a short-term exercise intervention may lead to positive changes in body fat percentage, WHR and aerobic fitness of overweight children. Therefore, school-based physical activity interventions can be an effective preventive strategy to control obesity and overweight in students.
authors.affiliation: Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Kelishadi
authors.affiliation: Sport Faculty, University of Isfahan, Isfahan, Iran.
authors.forename: Vazgen
authors.initials: V
authors.lastname: Minasian
authors.affiliation: Sport Faculty, University of Isfahan, Isfahan, Iran.
authors.forename: Sayed Mohammad
authors.initials: SM
authors.lastname: Marandi
authors.affiliation: Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ziba
authors.initials: Z
authors.lastname: Farajzadegan
authors.affiliation: School of Medicine and and Social Determinants of Health Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Pooyan
authors.initials: P
authors.lastname: Khalighinejad
authors.affiliation: Vice-chancellery for Research, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Soheila
authors.initials: S
authors.lastname: Shirdavani
authors.affiliation: Provincial Health Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Razieh
authors.initials: R
authors.lastname: Omidi
keywords: Intervention; middle school; obesity; physical activity; students