The Effects of Different Exercise Intensities and Modalities on Cortisol Production in Healthy Individuals: A Review

Cortisol is a hormone that is secreted in response to physiological stress. Exercise contributes significantly to changes in circulating cortisol concentrations. With exercise, there is increased activation of the sympathetic system to stimulate the release of adrenocorticotropic hormone, which releases cortisol into the blood. Current research has predominately studied the effects that aerobic exercise and resistance training have on cortisol production. Prolonged aerobic exercise, especially at higher intensities, significantly elevates cortisol concentrations when compared to similar duration and intensities of resistance exercise. Age, gender, physical fitness level, exercise intensity, training status, and modality are all variables that influence the production of cortisol. Elevated cortisol concentrations are highly indicative of muscle catabolism, increasing the loss of lean muscle tissue. This is a significant health concern for the growing elderly population. The rate of cortisol production changes as an individual ages and has been observed to have differing responses to exercise intensities in males and females. Cortisol production is correlated with exercise intensity and duration but does not increase the same across all exercise intensities. Higher exercise intensities and duration appear to be the main contributing factors that influence the production of cortisol, increasing the potential for muscle catabolism and muscle loss.