Habitual physical activity is an important inhibitory factor on age-related decreases in arterial distensibility, but the arterial segments affected by the inhibitory effect, or effective amount and quality of physical activity have not been clarified. We investigated the effect of the amount and quality of physical activity on the distensibility of different segments of arteries in the elderly. Subjects were 162 freeliving Japanese aged 65-86 years (71 men, 91 women). An accelerometer provided step count (year-averaged daily step count) and physical activity intensity (yearaveraged duration of physical activity > 3 METs) data throughout each 24-h period for one year. At the end of the year, arterial stiffness was evaluated by measuring pulse wave velocity (PWV) in the heart-carotid, heart-brachial, heart-femoral, and femoral-ankle segments using an automatic device. Significant negative correlations of the year-averaged daily step count and duration of physical activity > 3 METs with hfPWV were noted. These relationships were marked even though the influences of gender, age, and SBP were excluded. When the year-averaged daily step count and duration of physical activity > 3 METs were divided into quartile, and hfPWV was compared, hfPWV was significantly higher only in the lowest quartile group compared to the other 3 groups in both parameters. Habitual physical activity is an independent aortic sclerosis-determining factor, and decreases in physical activity promote aortic sclerosis, but the findings suggested that maintenance of physical activity at a certain level maintains aortic distensibility, and both the amount and intensity of physical activity are important.

DESCENTE SPORTS SCIENCE Vol.28/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE