The purpose of this study was to investigate whether the amount of time participants exercised in the target heart rate zone (THRZ) influenced change in blood pressure (BP) one year following a cardiac event. Lifestyle exercise (habitual, small exercise opportunities) and intensity were objectively measured using portable heart rate monitors. Linear mixed models were used to analyze change in BP among 331 participants. Mean BP at baseline was 118/70 mmHg, and both systolic and diastolic BP increased from baseline to one year-4.79 mmHg (p <.001) and 2.09 mmHg (p =.002), respectively. Overall, participants had a decrease in levels of lifestyle exercise. After controlling for time, age, gender, and study group, SBP change was inversely associated with amount of time in THRZ. Given suboptimal engagement in recommended exercise, the underlying mechanisms of lifestyle exercise effects on the time spent in THRZ to reduce BP warrants further study in this population.
Keywords: Exercise; blood pressure; cardiovascular disease; older adults; target heart rate.