Commuting by bicycle (vs. by car) is associated with improved aerobic power, microvascular function and diminished CO ₂ output in the atmosphere

The study investigated whether bicycle compared with car commuting, over relatively small distances, has positive effects on physiological variables, cardiometabolic fitness and CO₂ output in the atmosphere. Bike Commuters (11 M, 15 F; age [median value (interquartile range)] 51.5 (38.3-56.8) years; body mass index [BMI] 22.8 (21.0-24.1) kg m^-2) were compared with Car Commuters (12 M, 19 F; age 47.0 (36.0-56.5) years; BMI 23.5 (21.4-24.9) kg m^-2). In a longitudinal arm of the study, 20 Car Commuters were re-evaluated after they switched for 24 weeks to bicycle commuting (Car→Bike Commuters). Measurements included peak aerobic power ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> <mml:mi>peak</mml:mi></mml:mrow> </mml:msub> <mml:annotation>${\dot V_{{{\mathrm{O}}_2}{\mathrm{peak}}}}$</mml:annotation></mml:semantics> </mml:math> ) and ventilatory thresholds on a cycle ergometer, blood flow increase in the common femoral artery during a passive leg movement (PLM) test, energy expenditure and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:mi>C</mml:mi> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:msub> <mml:annotation>${\dot V_{{\mathrm{C}}{{\mathrm{O}}_2}}}$</mml:annotation></mml:semantics> </mml:math> exhaled during commuting. Bike Commuters had higher <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> <mml:mi>peak</mml:mi></mml:mrow> </mml:msub> <mml:annotation>${\dot V_{{{\mathrm{O}}_2}{\mathrm{peak}}}}$</mml:annotation></mml:semantics> </mml:math> (33.7 (31.3-38.1) versus 25.3 (23.5-28.9) mL kg^-1 min^-1, P < 0.001) and ventilatory thresholds than Car Commuters, higher Δpeak blood flow (+25%, P = 0.04) and area under the blood flow versus time curve (+46%, P = 0.03) during PLM, and an enhanced skeletal muscle oxidative metabolism. <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> <mml:mi>peak</mml:mi></mml:mrow> </mml:msub> <mml:annotation>${\dot V_{{{\mathrm{O}}_2}{\mathrm{peak}}}}$</mml:annotation></mml:semantics> </mml:math> and PLM variables increased in Car→Bike Commuters. Metabolic CO₂ output during bicycle commuting was ∼12 times less than that for a petrol car. In moderately active individuals, short-distance bicycle commuting at moderate intensity was associated, compared with car commuting, with positive effects on several physiological functions and environmental factors.