CARDIAC AUTONOMIC MODULATION IN INDIVIDUALS WITH CONTROLLED AND UNCOMPLICATED HYPERTENSION DURING EXERCISE-HEAT STRESS.

Abstract

Impaired cardiac autonomic modulation is implicated in the development of hypertension. Exercise improves sympathovagal balance and is often prescribed for hypertension management. Environmental conditions, however, are not considered during the development of these exercise recommendations. We examined cardiac autonomic modulation, assessed using heart rate variability (HRV), in individuals (49-77 years) with (n=20) and without (n=28) controlled, uncomplicated hypertension performing three 30-minute bouts of exercise (light, moderate, vigorous) in dry heat (40.2±0.3˚C, 17±7% relative humidity), each separated by 15-minute breaks. Regardless of intensity, short bouts of exercise-heat stress did not significantly disrupt HRV in individuals with hypertension relative to normotensives.