Cortisol has often been unfairly demonized in the context of high-intensity exercise. This has led some individuals with PCOS (polycystic ovary syndrome) to avoid exercise, fearing that cortisol will worsen their insulin resistance. However, this concern is largely unfounded.
Understanding Cortisol
Cortisol is a critical hormone produced by the adrenal glands, essential for survival. It helps maintain blood pressure, blood glucose levels, and initiates a normal stress response. In conditions of excessive cortisol, such as Cushing’s syndrome or when taking glucocorticoids for medical reasons, various side effects can occur, including insulin resistance, hypertension, weight gain, and immune suppression. However, these effects are seen in disease states where cortisol is released uncontrollably, not during normal fluctuations or stress responses.
Stress and Cortisol
When the body is subjected to significant physical or psychological stress without adequate recovery, cortisol levels may rise, potentially causing slight adverse effects. However, these effects are not comparable to those seen in disease states. It’s important to understand that it is the behaviour driving the cortisol levels, not the cortisol itself being pathological.
Types of Stress
Factors that can increase cortisol levels include:
- Sleep deprivation
- Fasted training/low energy availability
- Psychological stress
- Illness
High-Intensity Exercise and Cortisol
High-intensity exercise increases cortisol, which is beneficial as it prepares the body by increasing blood glucose levels. As long as you refuel and rest appropriately, cortisol levels will decrease. All forms of exercise are beneficial, with moderate to high-intensity exercise showing strong evidence for reducing the risk of chronic diseases, lowering inflammation, and improving mental health. In PCOS, higher intensity training has been shown to restore ovulation and improve insulin sensitivity and should not be avoided due to cortisol concerns.
Balancing Exercise and Recovery
While high-intensity training is beneficial, it should not be done every day. The body can only absorb and recover from a certain amount of stimulus/load. Rest and recovery are critical, and cortisol spikes are a normal, functional aspect of physiology that should not be demonized. 😊