Cortisol, a steroid hormone your adrenal glands produce, has widespread and varied effects throughout your body. It plays roles in stress management, exercise and inflammation. Your cortisol levels rise and fall in response to these conditions. Cortisol can inhibit the immune system, suppressing inflammation. Its anti-inflammatory effects make cortisol a useful drug in conditions where inflammation needs to be controlled, such as forms of arthritis and autoimmune conditions.

Exercise Effects

Cortisol's main purpose during exercise is to raise your blood sugar level to make glucose available to parts of the body, such as your heart, lungs and muscles, where it is needed most. To accomplish this, cortisol inhibits insulin secretion, promotes the breakdown of proteins and fats throughout the body and stimulates the liver to use these compounds to manufacture glucose. To balance its blood sugar-raising effect, cortisol stimulates the liver to produce glycogen, the short-term storage form of glucose. Concurrent with cortisol release, a part of your brain known as the hypothalamus releases a hormone called vasopressin, which causes the kidneys to retain water, thereby increasing blood pressure. As part of the cortisol response, in moderate exercise your brain releases the neurotransmitter dopamine, which heightens your motivation and enjoyment of your exercise.

Duration and Intensity

Longer sessions of exercise, such as increased sets in weight training, or endurance activities, such as jogging, may increase cortisol levels more than brief sessions of exercise. A study published in the May 2012 issue of the "Journal of Strength and Conditioning Research" found that high-intensity exercise causes greater elevations of cortisol than moderate-intensity exercise. High-intensity exercise may also result in overtraining, a condition characterized by decreased performance, fatigue and constant soreness. In the study, trained men and women performed high-intensity bouts of weight training. Results showed considerably higher cortisol values than for more typical strength training routines. Researchers recommend gradual implementation of high-intensity exercise to avoid injury and setbacks in reaching training goals.

Detrimental Effects

Cortisol helps prepare your body for physical activity, whether it be recreational exercise or to respond to a dangerous or threatening situation. When your cortisol levels remain elevated for prolonged amounts of time, though, your health may suffer. Excessive fatigue, sleep disturbance, elevated heart rate during exercise and prolonged recovery times are associated with chronically high cortisol levels. Detrimental effects, such as depression, brain atrophy, cognitive decline, abdominal obesity and decreased bone mass can also occur.

Stress Reduction

Moderate exercise may be useful for reducing stress-related depression, which is associated with elevated cortisol levels, concludes a study published in the April 2012 issue of the "International Journal of Sports Medicine." In the laboratory study of rats, a 10-week swimming program resulted in increased levels of serotonin, noradrenaline and dopamine, brain neurotransmitters that are all decreased in depression.

About the Author


Photo Credits

  • Jupiterimages/Comstock/Getty Images