Physical Activity and Stress Reactivity
- Stephen H. BoutcherStephen H. BoutcherAssociate Professor, School of Medical Sciences, University of New South Wales
Cardiovascular disease has been estimated to be responsible for over 30% of deaths worldwide. The traditional cardiovascular risk factors of smoking, obesity, diabetes, physical inactivity, and family history predict about 50% of the variance of new cardiovascular disease cases; therefore, a number of other risk factors must contribute to cardiovascular disease development. One such factor is psychological stress, which has been identified as playing a role in the development of cardiovascular disease. The major research strategy for assessing the impact of psychological stress on cardiovascular disease development is to measure cardiovascular reactivity to laboratory mental stressors. Exaggerated mental stress-induced cardiovascular reactivity and slow stressor recovery have been associated with the development of cardiovascular disease.
In contrast to exposure to psychological stress, there is strong evidence that participation in aerobic exercise leads to a reduction in cardiovascular disease. Participation in regular aerobic exercise generally reduces the cardiovascular response to acute exercise; therefore, researchers have hypothesized that the ability of aerobic exercise to enhance cardiovascular health works partly by modifying the cardiovascular reactivity response to mental stressors. There is mixed evidence to suggest that chronic aerobic exercise decreases or increases cardiovascular reactivity to mental challenge in normotensive, healthy individuals. A decrease in reactivity, however, has been found in those studies that have examined individuals at risk of disease or diseased adults. The optimal volume and intensity of aerobic exercise that brings about maximum decreases in cardiovascular reactivity has yet to be determined. The impact of other forms of exercise on reactivity such as resistance exercise and interval sprinting exercise is starting to be assessed. The challenge for researchers in this area is to identify the mode of exercise that takes the least amount of time but brings about the greatest reduction of levels of stress-induced cardiovascular disease.