Bicycle Commuting Over Relatively Short Distances (Vs. Commuting By Car) Is Associated With Higher Aerobic Power, Improved Microvascular Function, Greatly Diminished CO2 Output In Atmosphere

When feasible, commuting from home to work by bicycle (vs. car) should represent an advantage both in terms of personal health and environmental pollution. PURPOSE: To determine whether bicycle compared with car commuting, over relatively short distances in a mid-size town like Udine (Italy, about 90,000 inhabitants) supports such concepts. METHODS: In a cross-sectional study, we compared a group of subjects (A) regularly commuting by bicycle (11 m and 15 f, age 43 ± 13 yr, body mass index [BMI] 22.7 ± 2.5 kg·m−2) and a group of subjects (S) commuting by car (12 m and 19 f, age 38 ± 14 yr, BMI 23.4 ± 2.8 kg·m−2). The following variables were determined: a) “Peak” aerobic power (V̇O2peak) during an incremental test on a cycle ergometer. b) Blood flow increase in the common femoral artery, by echo-Doppler, during 1-min of passive leg movement (PLM) to evaluate microvascular/endothelial function. c) V̇CO2 exhaled during a usual one way commute trip with a portable metabolimeter. d) Blood biomarkers related to cardiovascular risk. 11 S dropped out and 20 S (7 m and 13 f, age 45 ± 11 yr, BMI 23.4 ± 2.8 kg·m−2) agreed to change commuting habits, from car to bicycle, for 24 weeks and repeated the same measurements (longitudinal study). PLM data were analysed in a sub-group of 20 A and 11 S. RESULTS: V̇O2peak was significantly higher in A vs. S (34.8 ± 5.3 ml.kg-1.min-1 vs. 26.7 ± 4.3; p<0.0001) V̇O2peak significantly increased in S after 24 weeks of bicycle commuting (+15%; p<0.0001), reaching a value closed to A. Variables measured during PLM such as peak blood flow, area under the blood flow vs. time curve (AUC) and common femoral artery diameter were significantly higher in A vs. S (+25%, +46% and +11% respectively; p<0.05). Peak and AUC values significantly increased in S after 24 weeks of bicycle commuting but did not reach values observed in A. Blood biomarkers were not different across groups. During bicycle commuting the weekly energy expenditure was 1127 ± 665 kcal.week-1, and the V̇CO2 output was 9.9 ± 3.2 g.km-1, that is about 10 times less than a typical hybrid car and 15 times less than a typical petrol car. CONCLUSIONS: Bicycle (vs. car) commuting over a relatively short distance (about 5 km and 17 min one way) is associated with: higher aerobic power; improved microvascular/endothelial function; greatly diminished CO2 output in the atmosphere.