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 min bouts of exercise (light, moderate, and vigorous) in dry heat (40.2 ± 0.3 °C, 17% ± 7% relative humidity), each separated by 15 min breaks. Regardless of intensity, short bouts of exercise-heat stress did not significantly disrupt HRV in physically active individuals with hypertension relative to normotensives. Take-home message During short bouts of light-to-vigorous exercise in the heat, controlled and uncomplicated hypertension did not significantly modulate HRV in physically active individuals. These findings can be used to refine guidance on use of exercise for hypertension management in the heat.