The Effect of Head-Out Aquatic Exercise on Arterial Stiffness in Middle-Aged and Elderly People

Aquatic exercise is ideal for older adults because it mitigates weight-bearing stress. However, the effect of head-out aquatic exercise on arterial stiffness, a strong future cardiovascular disease (CVD) risk, remains unclear. We determined whether head-out aquatic exercise would mitigate arterial stiffness in middle-aged and elderly people. In 25 middle-aged and older people (9 men, mean age 64 ± 8 years), blood pressure (BP) and brachial-ankle pulse wave velocity (baPWV) were measured before and after a supervised aquatic exercise training program (60 min, 1 session/week, 14 sessions) which mainly consisted of walking, stretching, and muscle strengthening in water. In the pooled subjects, systolic BP tended to decrease (p = 0.07) after the training intervention, whereas no significant changes were observed, including baPWV (from 1,537 ± 301 to 1,496 ± 308 cm/s). In the sub-analysis, by dividing subjects into a healthy group (n = 13) and a CVD risk group (n = 12), no significant interaction between time and group was seen in BP. On the other hand, baPWV decreased significantly in the healthy group (from 1,476 ± 299 to 1,365 ± 215 cm/s) but not in the CVD risk group (from 1,603 ± 301 to 1,637 ± 339 cm/s). The current study demonstrates that regular head-out aquatic exercise, even at a low frequency, could mitigate CVD risk in apparently healthy middle-aged and older people.