The role of the human hypothalamus-pituitary-adrenocortical system in adaptation to physical exercise

Abstract

Regular physical activity, especially associated with the development of aerobic abilities, helps to improve the physical and mental health of a person. Increasing the level of fitness reduces the risk of overall mortality for both healthy people and people with chronic diseases. Exercise is accompanied by activation of the hypothalamic-pituitary-adrenocortical axis (HPA). The degree of its activation depends primarily on the intensity and duration of the load. Glucocorticoids of the adrenal glands which are hormones of the final link of the HPA, and their synthetic analogs can have a positive effect on the physical form of people. They adapt carbohydrate and fat metabolism to the energy needs of the body during exercise; have anti-inflammatory and immunosuppressive effects, protecting working muscles from damage. Adaptation to regular physical activity changes the reactivity of HPA most often in the direction of decreasing its susceptibility to negative feedback. It is also accompanied by changes in the sensitivity of tissues to glucocorticoids, which may be associated with the appearance of variations in the number and sensitivity of glucocorticoid receptors. The review describes the factors influencing the reaction of the HPA system in response to acute and chronic exercise, discusses the role of this system in adaptation of a person to physical activity. The great influence of individual characteristics of a person on the level of HPA reactivity during exercise is emphasized.