title: Physical activity evaluation in Yugoslav Study of the Precursors of Atherosclerosis in School Children - YUSAD study.
abstract: BACKGROUND
  It is observed that there is a lack of physical activity and exercise in children, stressing higher prevalence of childhood obesity. The purpose of the study was to evaluate duration of physical activity in a child population and correlation of dynamics in physical activity during 5 years of follow-up in the same population.
  
  
  METHODS
  We evaluated 3243 school children from 12 regional centres across Serbia. The first examination was done when the children were 10 years old (baseline group), while the second examination was done on the same population when children were 15 years old. Physical activity was classified as recreational activity after school. We analysed 3 groups regarding physical activity: a group of children who were physically active less than 1 hour per day (group I), a second group active from 1 hour to < 3 hours per day (group II), and a third group active ≥ 3 hours per day (group III).
  
  
  RESULTS
  In our study we have found on examination that the majority of children were physically active between 1 and 3 hours per day. Our results indicate that there is significant movement from groups I and III toward group II on the second examination regarding the proportion in the baseline group. There is a significant increase in the number of children in group I as they get older.
  
  
  CONCLUSIONS
  School children in Serbia are physically active predominantly between 1 and 3 hours per day at the age between 10 and 15 years.
authors.affiliation: School of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Slavko
authors.initials: S
authors.lastname: Simeunovic
authors.forename: Zeljka
authors.initials: Z
authors.lastname: Milincic
authors.forename: Dejan
authors.initials: D
authors.lastname: Nikolic
authors.forename: Dejan
authors.initials: D
authors.lastname: Simeunovic
authors.forename: Dragana
authors.initials: D
authors.lastname: Arandjelovic
authors.forename: Ivana
authors.initials: I
authors.lastname: Novakovic
authors.forename: Ivana
authors.initials: I
authors.lastname: Petronic
authors.forename: Dijana
authors.initials: D
authors.lastname: Risimic
authors.forename: Srecko
authors.initials: S
authors.lastname: Nedeljkovic
authors.forename: Milija
authors.initials: M
authors.lastname: Vukotic