title: Physical activity levels and patterns of 9- and 15-yr-old European children.
abstract: OBJECTIVE
  The purpose of this study was to assess physical activity levels and patterns from children participating in the European Youth Heart Study (EYHS). Very limited physical activity data exist that have been collected from representative samples of children and even fewer data collected where physical activity has been measured using objective methods.
  
  
  METHODS
  Subjects were 2185 children aged 9 and 15 yr from Denmark, Portugal, Estonia, and Norway. Physical activity data were obtained using MTI (formerly CSA) accelerometers. The primary outcome variable was established as the child's activity level (accelerometer counts per minute). Children wore the accelerometer for 3 or 4 d, which included at least 1 weekend day.
  
  
  RESULTS
  Boys were more active than girls at age 9 (784 +/- 282 vs 649 +/- 204 counts.min-1) and 15 yr (615 +/- 228 vs 491 +/- 163 counts.min-1). With respect to time engaged in moderate-intensity activity, gender differences were apparent at age 9 (192 +/- 66 vs 160 +/- 54 min.d-1) and age 15 (99 +/- 45 vs 73 +/- 32 min.d-1). At age 9, the great majority of boys and girls achieved current health-related physical activity recommendations (97.4% and 97.6%, respectively). At age 15, fewer children achieved the guidelines and gender differences were apparent (boys 81.9% vs girls 62.0%).
  
  
  CONCLUSIONS
  Accelerometers are a feasible and accurate instrument for use in large epidemiological studies of children's activity. Boys tend to be more active than girls, and there is a marked reduction in activity over the adolescent years. The great majority of younger children achieve current physical activity recommendations, whereas fewer older children do so-especially older girls.
authors.affiliation: Department of Exercise and Health Sciences, University of Bristol, Bristol, UK. c.riddoch@mdx.ac.uk
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Riddoch
authors.forename: Lars
authors.initials: L
authors.lastname: Bo Andersen
authors.forename: Niels
authors.initials: N
authors.lastname: Wedderkopp
authors.forename: Maarike
authors.initials: M
authors.lastname: Harro
authors.forename: Lena
authors.initials: L
authors.lastname: Klasson-Heggebø
authors.forename: Luis B
authors.initials: LB
authors.lastname: Sardinha
authors.forename: Ashley R
authors.initials: AR
authors.lastname: Cooper
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
mesh_terms: D000054:Acceleration; D000293:Adolescent; D017677:Age Distribution; D000704:Analysis of Variance; D002648:Child; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D009043:Motor Activity / Q000502:physiology*; D017678:Sex Distribution; D012984:Software