ACUTE AEROBIC EXERCISE REDUCES AMBULATORY BLOOD-PRESSURE IN BORDERLINE HYPERTENSIVE MEN AND WOMEN

Ambulatory blood pressure (BP) monitoring was undertaken on two days i n 31 men and women (11 with elevated resting and ambulatory BP and 20 who were normotensive), once following each of these treatment conditi ons: 20 min of moderate aerobic bicycle ergometry, and an equivalent c ontrol rest period. The two monitoring days were conducted within a 72 h period with the order of treatments counterbalanced across subjects . Mean BP and heart rate (HR) levels were calculated for each individu al on an hourly basis and for work, home, and sleep periods. In the el evated BP group, the exercise day compared to the control day was asso ciated with lower BP at work. Hour-by-hour analyses confirmed that the BP-lowering effect of exercise was significant for 5 h and diminished in magnitude between hours 6 and 9. These effects were not attributab le to any marked differences in mood, total daily stress, posture, or activities between test days. Exercise was not associated with any app reciable differences in sleep BP or in the 24-h HR profile. No differe nces in BP or HR as a function of exercise were seen in the normotensi ve group; however, the exercise-induced reduction in mean arterial BP (MAP) for hours 2 through 5 was significantly positively correlated wi th control day MAP levels at work in the total sample. Thus, moderate aerobic exercise, when engaged in prior to the stresses of daily livin g, seems to confer a protective reduction in ambulatory BP, particular ly in individuals with elevated BP.