Effects of Commuter Cycling on Physical Activity, Cardiometabolic Health and Body Composition

The aim of this study was to evaluate effects of a 10-week commuter cycling intervention on physical activity (PA), cardiometabolic health and body composition. A randomised controlled trial was conducted in healthy males and females (n = 26, BMI ≤ 30, ≥ 20 years ≤ 55 years). The intervention group (CYC) cycle commuted (148 ± 38 min.wk^-1). The control group (CON) received public transport or petrol vouchers. $\dot{V}$ O_2max increased in CYC (10.5 ± 16.2%), decreased in CON (-2.8 ± 12.3%) (p = 0.03). HR_rest decreased in CYC (-5.4 ± 6.8%), increased in CON (1.7 ± 9.5%) (p = 0.02) as did diastolic blood pressure (-1.2 ± 7.5%, 11.9 ± 16.5%, respectively, p = 0.02). Weekly logbooks indicated no group difference in total PA (Group p = 0.15) or change over time (p = 0.18). CYC conducted more moderate and vigorous PA combined (p = 0.008). No changes in body mass were observed (CYC: wk0 78.5 ± 9.0, wk10 78.7 ± 9.0, CON: wk0 69.8 ± 6.7, wk10 70.3 ± 6.7 (p = 0.17), or difference between groups (p = 0.61). Body fat (sum of 4 skinfolds) was maintained similarly in both groups (p = 0.95). Body fat (DXA) was 29.4 ± 9. 7% before and 29.5 ± 9.8% after in CYC (p = 0.97). The intervention did not alter C-reactive protein, HDL, LDL, or total cholesterol, fasting glucose, insulin or HOMA-IR (p > 0.05). In conclusion, some cardiovascular benefits can occur with commuter cycling even if total PA and body composition are not altered. The increase in more intensive PA is likely responsible for the enhanced cardiovascular fitness. TRIAL REGISTRATION: The study was registered with the Australian New Zealand Clinical Trials Registry (ANZTCR:12617000123347).