EFFECTS OF ONE-LEGGED EXERCISE ON LEG ARTERIAL STIFFNESS

Abstract

A previous study reported that leg arterial stiffness decreases after moderate-intensity cycling (Kingwell et al. 1997). To determine whether the exercise-induced decrease in the leg arterial stiffness is systemic in nature or is rather confined to the arteries supplying exercising muscles, eight young male subjects performed three bouts of one-legged cycling (mild = 30%, moderate = 50%, and heavy = 80% of one-legged peak Vo2, 40 min) in a randomized order at the same time of day one week apart. Measurements of leg (femoral-dorsalis pedis) pulse wave velocity (PWV) and femoral blood flow (via Doppler ultrasound) were made both before and after each bout of one-legged cycling. There were no baseline differences between exercised and unexercised legs or any effects of intensity on any parameters measured. In the exercised leg, leg PWV significantly decreased ∼9–10% (moderate, 823 ± 27 to 765 ± 25 cm/s; heavy, 839 ± 25 to 762 ± 28 cm/s; mean ± SE) and femoral blood flow increased ∼10–20% after moderate and heavy cycling, but there were no changes after mild cycling. These changes after moderate and heavy cycling returned to the baseline completely during 90 min recovery. In contrast, there were no significant differences in any parameters in the unexercised leg. The change in leg PWV in the exercised leg was significantly related to that in the femoral blood flow (r = 0.41, P < 0.001) whereas there was no such relation in the unexercised leg (r = 0.07, NS). These results support the hypothesis that the regional, rather than systemic, factors are associated with the decrease in arterial stiffness induced by moderate or heavy exercise. (Supported by JSPS: 13780041)