The effects of two aerobic training intensities on ambulatory blood pressure in hypertensive patients: results of a randomized trial

Abstract

The effect of different intensities of aerobic exercise on blood pressure remains uncertain. The goal of this trial was to compare the effect of two different levels of aerobic physical training on 24-hour ambulatory blood pressure. In this double-blind parallel-group trial, 28 sedentary hypertensive patients (mean diastolic blood pressure of 90 to 104 mm Hg) were randomly assigned to 10 weeks of physical training at 20% (Group I) or 60% (Group II) of their maximal workload on a cycle ergometer (mean load of 32 and 85 watts, respectively). Maximal oxygen consumption was estimated by the time spent on a mechanical braked Monark bicycle (Monark, Sáo Paulo, Brazil). Indexes of physical fitness were determined by cycle ergometer tests before and after the experimental period. The principal outcome variable was mean 24-hour ambulatory blood pressure. Mean 24 hour systolic blood pressure fell from 137.2+/-14.9 to 135.2+/-12.7 mm Hg in Group I and from 144.4+/-13.3 to 138.6+/-12.9 in Group II (mean between group difference of -2.1 mm Hg, P = 0.479, adjusted for baseline blood pressure). Mean diastolic blood pressure fell from 9.21+/-10.0 to 89.3+/-7.7 mm Hg in Group I and from 93.3+/-5.8 to 90.6+/-6.8 mm Hg in Group II (mean adjusted difference of -0.06, P = 0.765). Nighttime blood pressure did not change in either group. Across all participants, a reduction in systolic blood pressure was significantly associated with improved physical fitness as manifest by increased physical work capacity at heart rate of 130 bpm (PWC130), increased systolic blood pressure at PWC130, and decreased maximum heart rate measured during the cycle ergometer test We conclude that aerobic training programs at 20% and 60% of the maximum work capacity have similar effects on ambulatory blood pressure.