title: Physical activity pattern of children assessed by triaxial accelerometry.
abstract: OBJECTIVE
  Accelerometry was used to assess the relationship between the physical activity level (PAL) and time spent on activities of various intensities in children.
  
  
  METHODS
  A total of 20 children aged 8.6+/-3.3 y wore a triaxial accelerometer (Tracmor2) for 2 weeks. PAL was calculated with Tracmor2 output data. The fraction of time spent on activities with a given level of intensity (low, moderate, high) was calculated. The fractions of time spent on activities of different intensities were compared with previously obtained data for young adults and elderly persons.
  
  
  RESULTS
  PAL showed an inverse relation with the percentage of time spent on low-intensity activities (r = -0.76; P < 0.0001) and a positive relation with the percentage of time spent on high-intensity activities (r = 0.93; P < 0.0001). The fraction of time spent on low-intensity activities was smaller in children than in young adults (P < 0.05) and elderly persons (P < 0.0001), while the fraction spent on high-intensity activities (P < 0.0001) was larger.
  
  
  CONCLUSIONS
  The present data are important for a better understanding of physical activity in children, which is necessary for education and prevention about physical (in)activity in childhood. Our observations suggest that to obtain a higher PAL in children, they should be given the opportunities to perform high-intensity activities.
authors.affiliation: Department of Pediatrics, University of Maastricht, The Netherlands. Marije.hoos@kg.unimaas.nl
authors.forename: M B
authors.initials: MB
authors.lastname: Hoos
authors.forename: H
authors.initials: H
authors.lastname: Kuipers
authors.forename: W-J M
authors.initials: WJ
authors.lastname: Gerver
authors.forename: K R
authors.initials: KR
authors.lastname: Westerterp
mesh_terms: D002648:Child; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000209:etiology / Q000517:prevention & control*; D012044:Regression Analysis; D013997:Time Factors