ABSTRACT

　Aquatic exercise is ideal for older adults because it mitigates weight-bearing stress. However, the effect of aquatic exercise on central arterial properties (e.g., proximal arterial stiffness and aortic blood pressure [BP]), strong determinants of future cardiovascular disease, remains unclear. We determined if aquatic exercise would decrease arterial stiffness and central blood pressure. To do so, we performed two experiments: firstly, we compared central arterial properties of lifelong Japanese pearl divers (Ama) with age-matched adults living in the same fishing villages (Study-1). Secondly, we determine the effect of regular aquatic exercise on central arterial properties in middle-aged and older adults (Study-2).In Study-1, we recruited 115 female pearl divers (mean age: 65±11 yr) as well as age-matched 50 physically inactive and 33 physically active female non-divers living in the same fishing villages in rural locations. Pulse wave velocity from the heart to the brachial artery (hbPWV; partly reflecting proximal aortic stiffness) and between the brachium and the ankle (baPWV; reflecting stiffness of abdominal aorta and leg arteries) were measured. No significant group differences were found in either brachial blood pressure or baPWV among the groups. hbPWV was 5% lower in physically active adults and 9% lower in Ama compared with their sedentary peers (P<0.05). There were no significant differences in central blood pressure among groups. In Study-2, central arterial properties were evaluated in twelve normotensives middle-aged and older peoples (mean age=66±9 yrs) before and after the supervised aquatic exercise program (90 min, 1 day/week, 3 months) which consisted of walking, stretching, and muscle strengthening in water. Following the training intervention, brachial and aortic systolic blood pressure and baPWV significantly decreased, whereas no significant change was seen in hbPWV. These results demonstrate that regular aquatic exercise, even at a low frequency, could mitigate cardiovascular disease risk in normotensive middle-aged and older people. The inconsistency of results between Study-1 and Study-2 might be attributed to the duration of experience (e.g. lifelong vs. 3 months).

DESCENTE SPORTS SCIENCE Vol.39/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE