title: Physical activity and respiratory symptoms in children: the Generation R Study.
abstract: BACKGROUND
  To assess the relationship between physical activity in second year of life and respiratory symptoms during the pre-school period.
  
  
  METHODS
  This study was embedded in the Generation R Study, a large prospective birth-cohort study in Rotterdam, the Netherlands. Physical activity was measured in the second year of life by an Actigraph accelerometer in a subgroup of 347 children (182 boys, 165 girls; mean age 25.1 months) and data were expressed as counts per 15 sec in categories: light activity (302-614 counts/15 sec), moderate activity (615-1,230 counts/15 sec), and vigorous activity (≥1,231 counts/15 sec). Respiratory symptoms were assessed by the International Study of Asthma and Allergies in Childhood Questionnaire in the third and fourth year of life.
  
  
  RESULTS
  Physical activity levels were not associated with wheezing symptoms in the third and fourth year of life (OR: 0.98; 95% CI: 0.92-1.05 and OR: 0.99; 95% CI: 0.92-1.07 for total activity, respectively), nor associated with shortness of breath symptoms (OR: 0.98; 95% CI: 0.92-1.05 and OR 1.03; 95% CI: 0.96-1.11 for total activity, respectively).
  
  
  CONCLUSIONS
  These results suggest that physical activity may not play an important role in the development of respiratory symptoms in pre-school children.
authors.affiliation: The Generation R Study Group, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Pediatrics, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Driessen
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Kiefte-de Jong
authors.forename: Vincent W V
authors.initials: VW
authors.lastname: Jaddoe
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Hein
authors.initials: H
authors.lastname: Raat
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.forename: Henriette A
authors.initials: HA
authors.lastname: Moll
mesh_terms: D001249:Asthma / Q000503:physiopathology*; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D011446:Prospective Studies
keywords: accelerometry; infants; physical activity; respiratory symptoms; shortness of breath; wheezing; young children