Acute aerobic exercise reduces ambulatory blood pressure in borderline hypertensive men and women.

Ambulatory blood pressure (BP) monitoring was undertaken on two days in 31 men and women (11 with elevated resting and ambulatory BP and 20 who were normotensive), once following each of these treatment conditions: 20 min of moderate aerobic bicycle ergometry, and an equivalent control 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 individual on an hourly basis and for work, home, and sleep periods, In the elevated BP group, the exercise day compared to the control day was associated 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 attributable to any marked differences in mood, total daily stress, posture, or activities between test days. Exercise was not associated with any appreciable differences in sleep BP or in the 24-h HR profile No differences in BP or HR as a function of exercise were seen in the normotensive group; however, the exercise-induced reduction in mean arterial BP (MAP) for hours 2 through 5 was significantly positively correlated with control day MAP levels at work in the total sample. Thus, moderate aerobic exercise, when engaged in prior to the stresses of daily living, seems to confer a protective reduction in ambulatory BP, particularly in individuals with elevated BP.