Do high-intensity workouts raise cortisol? Here's why the stress hormone isn't always bad

Wellness influencers have recently focused on cortisol, often blaming the stress hormone for issues like weight gain and fatigue. A common suggestion is that intense or prolonged exercise excessively stresses the body, leading to unhealthy cortisol spikes. However, scientists clarify that this view misinterprets cortisol's essential role.

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Cortisol’s main role is to help your body respond to stress: When you are under strain, your adrenal glands release the hormone to help set off the so-called fight-or-flight response.

Cortisol is vital for health, primarily helping the body respond to stress by initiating the fight-or-flight response. It increases blood flow to muscles and provides energy by converting carbohydrates into fuel, actions crucial for survival in perceived danger. Dr. Lena Fan, an endocrinologist at Mount Sinai, notes that cortisol also aids in fighting infection and inflammation, and regulates heart rate, blood pressure, blood sugar, and sleep cycles.

While social media discussions might suggest chronically high cortisol is common, actual cortisol disorders are rare, affecting only about 1% of the population. Even individuals experiencing chronic stress or anxiety typically see cortisol levels rise within the normal range, according to Dr. Fan.

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While chronically high cortisol may seem common from conversations on social media, cortisol disorders are, in fact, rare

Strenuous exercise naturally signals the body to release cortisol, which benefits muscles by delivering more oxygen during a workout. Anthony Hackney, a professor emeritus of exercise physiology, explains that cortisol levels remain elevated for a few hours post-exercise. Once the body recovers and refuels, these levels typically drop, often below the starting point.

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Cortisol typically stays high for a few hours after exercise, but once you’ve recovered and refueled, it drops back down, often to a lower level than where it started.

To achieve the stress-lowering benefits of exercise and reduce baseline cortisol, proper nutrition and recovery are key. Dr. Marie Schaefer of the Cleveland Clinic emphasizes that insufficient fuel, particularly carbohydrates, after a hard workout can prolong high cortisol levels. Overtraining without adequate rest can also diminish the positive effects of exercise on stress reduction.

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If you do a hard workout but haven’t eaten enough fuel, including carbohydrates, it may feel more challenging and your cortisol will likely remain high for longer afterward