Inter-limb Changes in Arterial Function after Intense Cycling Exercise

We investigated whether muscle exercise, by inducing a subsequent local response, alters local and systemic arterial function differently. Eleven healthy volunteers (31±8 years) performed a 45-min cycling session at a heart rate corresponding to 10% above ventilatory threshold. Measurements were performed before and 45 min after exercise. Central and peripheral blood pressures were assessed by applanation tonometry and automatic sphygmomanometer, respectively. Brachial and popliteal arterial changes in diameter and blood flow were assessed using ultrasonography. The endothelium-dependent function was assessed simultaneously on brachial and popliteal arteries by flow-mediated dilation. Systolic blood pressure decreased significantly in both upper and lower limbs as well as centrally. Ankle-brachial index decreased significantly. Cross-sectional area and blood flow of popliteal and brachial arteries increased significantly. The increase in blood flow was higher in the brachial than in the popliteal artery, whereas diameter increase was of similar magnitude between the two arteries. When normalized with shear rate, brachial flow-mediated dilation was significantly greater, whereas popliteal flow-mediated dilation was similar post- vs. pre-exercise. After an acute bout of intense cycling, blood flow increase and endothelial function were greater in the non-exercised upper limb compared to the exercised lower limb, suggesting that anaerobic exercise blunts the enhancement of systemic endothelium-dependant vasodilation in active muscle beds.