Exercise protects cardiovascular recovery from stress in a sample of Black ethnicity adolescents

Abstract

Background: Exaggerated cardiovascular response to a subsequent psychosocial challenge (cardiovascular reactivity) have an adverse effect on future cardiovascular risk status in younger populations. Several studies have shown that black individuals exhibited significantly greater blood pressure (BP) and heart rate (HR) responses to stressors than white individuals. The purpose of the study was to determine whether interval exercise reduces cardiovascular reactivity and recovery from stress in black adolescents. Methods: In a counterbalanced order and one-week apart, black Cuban adolescents (n=25) completed an interval exercise program followed by the Trier Social Stress Test for Child (TSST-C) and no exercise followed by the TSST-C. The exercise consisted of a cycle ergometer fitness test (5-min, 50 rpm, 60% HR reserve), followed by 60-s rest, and another bout of exercise (6-min, 80 rpm, 30-s intervals) at the resistance that elicited the target HR reserve during the fitness test. Adolescents rested 2-min before completing another 6- and 4-min interval exercises. Following a 5-min post-intervention period, adolescents completed the TSST-C. BP, HR and heart rate variability (HRV) were measured before, during and after the exercise and TSST-C. Results: Systolic blood pressure (SBP) remained unchanged following exercise. TSST-C-induced changes in BP, HR and HRV reactivity were not reduced for aerobic exercise. Recovery SBP and HR were reduced in the exercise condition (P<0.01, CI95% = -8.36, -2.51, and P<0.01, CI95% = -8.07, -4.31, respectively). Conclusions: Acute interval aerobic exercise appears to have a significant impact on cardiovascular recovery in black adolescents who have suffered stressful events.