The impact of acute and chronic exercise on the psychophysiological responses to real-life and cognitive stressors

Abstract

Heightened stress responses may be linked to the pathogenesis of various cardiovascular diseases. Individuals who are fitter and more physically active or have just completed an acute bout of exercise are proposed to have an attenuated cardiovascular stressor response. However, research to date utilises mainly laboratory-based stressors and there is a paucity of research investigating real-life stressors. Three studies were conducted to examine these relationships. Firstly, current fitness and physical activity levels and musicians' (n=58) psychological and physiological responses to musical performance (real-life stressor) and cognitive laboratory stressors were examined. Results showed that fitness was positively related to heart rate reactivity pre-real-life stressor but inversely related to absolute heart rate during a cognitive laboratory stressor. Physical activity was not related to any of the psychological or physiological measures pre- or during a real-life or laboratory stressor. Fitter individuals in this sample did not show a differentiated pattern of heart rate variability response prior to a real-life stressor. Secondly, the effect of l6 weeks of aerobic training (n=12) on psychological and physiological responses to a musical performance and a cognitive laboratory stressor were examined, and compared to an Alexander Technique group (n=9). Aerobic training resulted in lower heart rate during the real-life stressor compared to the Alexander Training. Finally, the effect of 20 min of exercise (70% VO₂max) on psychological and physiological indices pre-stressor were compared to no exercise (n=12) in a within-subject random crossover design. Patterns of heart rate, blood pressure and heart rate variability were similar for both conditions. Overall these results provide mixed evidence on the benefits of exercise, fitness and physical activity in altering individuals' responses to stressors. The use of musical performance as a real-life stressor is generally supported, but differences are noted between study conditions suggesting that study design needs careful consideration when working with real-life stressors.