CORTISOL
YOUR FRIEND OR YOUR ENEMY?
Cortisol is often referred to as the body's primary stress hormone. It follows a natural daily rhythm known as the cortisol curve and in healthy individuals cortisol will peak within 30–45 minutes after waking, helping to increase alertness, mobilize energy, and regulate metabolism. Throughout the day, levels gradually decline, reaching their lowest point in the evening to support relaxation and sleep. This cycle is tightly regulated by the hypothalamic-pituitary-adrenal (HPA) axis and is essential for maintaining homeostasis, immune function, and cognitive performance. However, chronic stress and certain lifestyle habits can disrupt this curve, leading to fatigue, mood disturbances, and metabolic imbalances.
One of the most significant disruptors of the cortisol curve is chronic psychological stress. Prolonged exposure to work-related stress, emotional distress, or trauma can keep cortisol levels elevated throughout the day, flattening the natural morning peak and preventing the expected evening decline. This dysregulation can lead to symptoms like chronic fatigue, poor sleep, increased abdominal fat storage, and insulin resistance.
Other lifestyle choices like inconsistent bedtimes, working night shifts, abuse of drugs and alcohol or bedtime blue light exposure from screens, can delay or blunt the morning cortisol surge. Individuals with chronic sleep deprivation or irregular sleep patterns often experience elevated nighttime cortisol and disruption of deep sleep cycles and recovery.
Diet and nutrition also significantly impact cortisol regulation as well. High-glycemic diets, excessive caffeine intake, and nutrient deficiencies (particularly in magnesium, vitamin C, and B vitamins) can all contribute to cortisol dysregulation. Consuming protein-rich meals in the morning, maintaining stable blood sugar levels throughout the day, and avoiding excessive stimulant use in the late afternoon can help maintain a balanced cortisol curve. Conversely, excessive caloric restriction or very low-carb diets without calorie periodization can prolong cortisol elevation due to the body's perception of energy scarcity.
Lastly, exercise timing and intensity influence cortisol dynamics. High-intensity workouts naturally elevate cortisol, which is beneficial when aligned with the body's natural rhythm, such as in the morning or early afternoon. However, excessive training without adequate recovery or performing high-intensity exercise late at night can prolong cortisol elevation, interfering with sleep and muscle recovery. Activities like yoga, light resistance training, and walking in the evening can help facilitate cortisol reduction and prepare the body for rest. On the contrary, explosive, fast, or heavy movements will activate the immune system and the nervous system and cause a cortisol spike.
Optimizing the cortisol curve requires a well balanced approach. Tools like managing stress exposure, prioritizing sleep hygiene, stabilizing blood sugar, and aligning exercise habits with the body's natural rhythm all can help re-establish a healthy cortisol curve. By focussing on a healthy cortisol cycle, individuals can improve energy levels, mental clarity, metabolic function, and overall resilience to stress. Understanding these daily fluctuations allows for more strategic lifestyle choices that support long-term well-being and peak performance.
A PEAK INTO PERFORMANCE METRICS:
When working with high performers in any industry it is important to remember that attention to detail is KING. The body does NOTHING in isolation. Just like one rock dropped into a lake creates waves that push out from the center of impact, one small change in one part of the body sends ripples throughout the entire system. The goal of working with high performers is to help them see, understand, and manage these signals.
One other major factor that plays a crucial role in a healthy Cortisol curve is a healthy gut biome. In your body, the daily Cortisol levels and the alertness of your immune system are positively correlated, meaning that when cortisol is elevated the immune system is on high alert and active. When cortisol levels are low, the immune system is depressed and less active. This make perfect sense when you think about it from sleep/wake cycle perspective. When the sun is up, cortisol should be up; and when the sun goes down, cortisol should go down. However, In modern society with lighted homes and cities, processed foods, and chronic toxic stress, our natural circadian rhythm is often disrupted, leading to a disruption in the daily cortisol curve.
For athletes who are eating right, living right, and training hard, but still experience symptoms like: the inability to fall asleep, anxiety in the evening, or poor sleep quality it may be that those symptoms are related to a spike in evening cortisol caused by the activation of the immune system from the overgrowth of bad bacteria in the gut. As we learned in the beginning of this blog post, cortisol levels and the immune system are like two cars on the same track. When one goes up the other follows. So for people who are living with gut biome dysfunction, every night when your cortisol levels drop and your immune system begins to decrease, your unhealthy gut biome start their party. This the moment their have been waiting for all day. As the immune system goes to sleep they begin to multiply and multiply and multiply as cortisol continues to pull down the alertness of the immune system. Now, your body is faced with a dilemma. Do we stay in the “healthy cortisol curve” and continue to suppress the immune system in order to get good sleep and recovery; or do we deal with this immediate problem of microbiome overgrowth and raise cortisol levels back up in order to fight off the bad bacteria invasion. Left unchecked this internal war will continue every night, often leading to melatonin over consumption, more poor sleep, and a more suppressed immune system. This eats away at muscle growth and development, neuromuscular connection, and hormone levels. It is far too common for people to be unknowingly stuck in this cycle for years or decades.
If you are experiencing any symptoms related to cortisol levels, please get them checked immediately.
As stated in this post, you cannot take one daily reading of cortisol and know where your level is at. Must establish a daily cortisol curve, meaning a minimum of 3 tests (in the same day). 4 tests is better than 3, 2 tests is almost pointless. If a Dr. or nutritionists only tests your cortisol once then it’s time to take your business elsewhere.
EATWATER
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