title: Tracking cardiorespiratory fitness and physical activity in children with and without motor coordination problems.
abstract: OBJECTIVE
  Previous research has shown children with Developmental Coordination Disorder (DCD) have lower cardiorespiratory fitness (CRF) than typically developing (TD) children. This has been hypothesized to be due to an activity deficit, whereby poor motor functioning discourages children from participating in physical activities, but this hypothesis has not been directly tested. In this study, we use longitudinal data to measure the extent to which physical activity explains differences in CRF between children with and without motor coordination deficits.
  
  
  METHODS
  Longitudinal observational study.
  
  
  METHODS
  The study sample is an open cohort of children, numbering 2278 at baseline (age 9-10), that was followed for up to 5 years (to age 13-14). Motor skills were assessed once over the study period. Children scoring at or below the 5th percentile (n=103) on the Bruininks-Oseretsky Test of Motor Proficiency-Short Form were considered to have possible DCD (pDCD). CRF (estimated peak VO2) was estimated from performance on the Léger 20m shuttle run test, and physical activity was measured with the Participation Questionnaire. Both fitness and physical activity were measured up to 7 times over the study period.
  
  
  RESULTS
  Children with pDCD had significantly lower CRF than their TD peers at each time point. CRF declined for both groups, but this decline was steeper for children with pDCD. Physical activity explained only a small part of the difference in CRF.
  
  
  CONCLUSIONS
  The activity deficit did not contribute to the persistent and gradually widening gap in CRF between children with and without possible DCD. Possible reasons for this and future directions are discussed.
authors.affiliation: Faculty of Kinesiology & Physical Education, University of Toronto, Canada; Department of Family Medicine, McMaster University, Canada; Department of Psychiatry & Behavioural Neurosciences, CanChild Centre for Studies in Childhood Disability, Offord Centre for Child Studies, McMaster University, Canada; INfant and Child Health (INCH) Lab, McMaster University, Canada. Electronic address: cairnej@mcmaster.ca.
authors.forename: John
authors.initials: J
authors.lastname: Cairney
authors.affiliation: Department of Family Medicine, McMaster University, Canada; INfant and Child Health (INCH) Lab, McMaster University, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Veldhuizen
authors.affiliation: Department of Kinesiology, McMaster University, Canada; INfant and Child Health (INCH) Lab, McMaster University, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: King-Dowling
authors.affiliation: Department of Health Sciences, Brock University, Canada.
authors.forename: Brent E
authors.initials: BE
authors.lastname: Faught
authors.affiliation: Department of Health Sciences, Brock University, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Hay
mesh_terms: D000293:Adolescent; D000072599:Cardiorespiratory Fitness / Q000502:physiology*; D002648:Child; D015444:Exercise; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D019957:Motor Skills Disorders / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D011795:Surveys and Questionnaires
keywords: Developmental Coordination Disorder; Motor skills; Motor skills disorders; Physical activity; Physical fitness; Youth