Exercise and the Brain : A Journey from the Exercise‐Glucocorticoid Paradox

Abstract

Glucocorticoid, also known as a “stress hormone”, has been considered to play a central mediator role in the detrimental effects of chronic stress on the brain, cognition, and mental health. Yet, physical exercise, despite activating the HPA axis and increasing glucocorticoid, exerts many beneficial effects to the brain, cognition, and mental health. Here, we will introduce this Exercise‐Glucocorticoid Paradox and propose three potential solutions to the paradox, 1) , exercise buffers the HPA‐axis response to novel stressors, 2) , exercise does not downregulate or even increases glucocorticoid receptors, and 3) , exercise increases medial prefrontal dopamine. Via examining the Exercise‐Glucocorticoid Paradox, we hope to provide an opportunity to reconsider the functional role of glucocorticoid in stress coping and in the pathophysiology of chronic stress and depression.