title: Longitudinal associations of cycling to school with adolescent fitness.
abstract: OBJECTIVE
  To investigate whether change in transport to school from non-cycling to cycling was associated with change in cardio-respiratory fitness (CRF) over a six-year follow-up.
  
  
  METHODS
  Participants were 384 children (9.7 (0.5) years) who participated in the Danish arm of the European Youth Heart Study in 1997 and who were followed up 6 years later. CRF was assessed by a maximal cycle ergometer test and travel to school was investigated by questionnaire at both time points. Linear regression models were used to investigate associations between CRF and change in mode of travel to school between baseline and follow-up.
  
  
  RESULTS
  Higher CRF was significantly associated with cycling to school in children and adolescents of both sexes. Longitudinal regression models showed that a change in travel mode from non-cycling to cycling was a significant predictor of CRF at follow-up (P<0.001) after adjustment for potential confounders. Participants who did not cycle to school at baseline, but who had changed to cycling at follow-up, were significantly fitter (0.33 W kg(-1)) than those who did not cycle to school at either time point (P=0.001), a difference of 9%.
  
  
  CONCLUSIONS
  Cycling to school may contribute to higher cardiovascular fitness in young people.
authors.affiliation: Exercise, Nutrition and Health Sciences, University of Bristol, UK. ashley.cooper@bris.ac.uk
authors.forename: Ashley R
authors.initials: AR
authors.lastname: Cooper
authors.forename: Niels
authors.initials: N
authors.lastname: Wedderkopp
authors.forename: Russell
authors.initials: R
authors.lastname: Jago
authors.forename: Peter L
authors.initials: PL
authors.lastname: Kristensen
authors.forename: Niels C
authors.initials: NC
authors.lastname: Moller
authors.forename: Karsten
authors.initials: K
authors.lastname: Froberg
authors.forename: Angie S
authors.initials: AS
authors.lastname: Page
authors.forename: Lars Bo
authors.initials: LB
authors.lastname: Andersen
mesh_terms: D000293:Adolescent; D001642:Bicycling / Q000502:physiology; D002319:Cardiovascular System; D002648:Child; D005080:Exercise Test; D005260:Female; D006304:Health Status; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D010809:Physical Fitness / Q000502:physiology; D012574:Schools; D013334:Students; D011795:Surveys and Questionnaires; D014186:Transportation