Bicycling to school improves the cardiometabolic risk factor profile: a randomised controlled trial

OBJECTIVES: To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children. DESIGN: Prospective, blinded, randomised controlled trial. SETTING: Single centre study in Odense, Denmark PARTICIPANTS: 43 children previously not bicycling to school were randomly allocated to control group (n=20) (ie, no change in lifestyle) or intervention group (ie, bicycling to school) (n=23). PRIMARY AND SECONDARY OUTCOME MEASURES: Change in cardiometabolic risk factor score and change in cardiorespiratory fitness. RESULTS: All participants measured at baseline returned at follow-up. Based upon intention-to-treat (ITT) analyses, clustering of cardiometabolic risk factors was lowered by 0.58 SD (95% CI -1.03 to -0.14, p=0.012) in the bicycling group compared to the control group. Cardiorespiratory fitness (l O(2)/min) per se did not increase significantly more in the intervention than in the control group (β=0.0337, 95% CI -0.06 to 0.12, p=0.458). CONCLUSIONS: Bicycling to school counteracted a clustering of cardiometabolic risk factors and should thus be recognised as potential prevention of type 2 diabetes mellitus and cardiovascular disease (CVD). The intervention did, however, not elicit a larger increase in cardiorespiratory fitness in the intervention group as compared with the control group. TRIAL REGISTRATION: Registered at http://www.clinicaltrials.gov (NCT01236222).