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).