There is an increasing recognition that pulse wave velocity (PWV), an index of arterial stiffness, changes transiently via alteration of vascular smooth muscular tone. The aim of this study was to determine whether acute change in leg PWV after a low- intensity exercise bout reflects endothelial function. Apparent healthy 6 young (21±1 years) and 10 older (69±3 years) adults male subjects were studied. Each subject was measured both leg PWV before and after a low-intensity single-leg pedaling exercise (20 watt, 5 min). Young subjects demonstrated a significant reduction in the exercised leg PWV (-8.0%), whereas the non-exercised leg PWV did not change significantly (+2.2%). These results suggest that the decrease in PWV in the exercised leg was induced mainly by exercise-related regional factors (e.g., endothelium-derived vosoactive substance). In older subjects, on the other hand, no significant changes in PWV were observed either in the exercised leg or the non-exercised leg. These results might indicate the aging-related impairment of endothelial function. Together, response of leg PWV to the single-leg pedaling might be a screening tool of endothelial dysfunction. In young subjects, however, responses of leg PWV to the single-leg pedaling did not change significantly after 8 weeks of endurance exercise training intervention. Further study to determine the sensitivity of this index is warranted.

DESCENTE SPORTS SCIENCE Vol.31/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE