Stressed Out? Cortisol and Creatine Kinase Play Big Roles

Dealing with stress and anxiety? Explore your body's signals, learn to manage high CK and cortisol, and reclaim your energy and health.

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By Staff Writer
Jovan Mijailovic
Edited by Jovan Mijailovic

Published March 6, 2024.

A tired woman looking up creatine kinase online.

Being stressed out is a 21st-century trend. If you're sleep-deprived, over-working, and constantly busy, you are deemed a super(wo)man. When did this become the norm, and why do we think we can keep charging full speed ahead?

While we may tell ourselves that more is better, checking in and seeing if our bodies can tolerate how we live is vital. Have you ever had a full night’s rest and woke up exhausted?

This is not normal, although many people experience it. And it would be best if you didn't trudge through life this way. The stress hormone—cortisol—is a critical component in these patterns, and it's essential to understand what we are looking for.

What is cortisol?

Cortisol is a hormone produced by our adrenal glands—the little hats that sit atop our kidneys—and is responsible for responding to physical and emotional stress. [1] It is best known for our fight-or-flight response and can be essential to increase energy production when under pressure.

Its levels are meant to follow our circadian rhythm. [2] They should be at their highest in the morning and fall throughout the day, reaching their lowest point around midnight or 2 hours after falling asleep.

Note: The body's stress response is meant for acute situations, like running or even when a predator is chasing us. You face a chronic issue if your commute to work, job, or relationship triggers it.

» Explore the significance of cortisol to testosterone ration

What is creatine kinase?

Creatine kinase (CK) reflects our body’s reaction to exercise, a specific type of stress, or a test of overall body strain. It rises when muscle damage occurs. [3] The value shows how your body is reacting to training load and intensity. This enzyme peaks about two to four days after intense exercise and returns to normal levels (<200 units) simultaneously.

Note: Chronically high CK levels will likely result in side effects like muscle pain, fatigue, injury, and more—which is not ideal for top athletic performance.

» Dispel common myths about creatine supplements

5 ways to lower CK and cortisol levels

1. Meditate

Everyone meditates differently, but finding time to reflect on your life has been shown to be helpful. [4] Even something as simple as taking a break from social media would be best, and could be considered a form of meditation for those that are always connected.

2. Add low-impact exercise

Exercise, work, and relationships can be causes of stress. You can quickly lower your CK and cortisol levels by doing yoga, swimming, and long walks on the beach. [5, 6]

Note: If you use a wearable fitness device, the InsideTracker mobile app can provide real-time, daily feedback by monitoring resting heart rate. It will help you reach your overall health goals. These insights also seamlessly integrate with your blood and DNA data.

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3. Get rid of excess stressors

While quitting your job or ending your stressful relationship would seem great, that's only sometimes realistic. You can try switching your commute, avoiding the news before bedtime, or changing how you respond to aggravation from colleagues.

4. Improve your sleeping habits

The body undergoes more stress from poor sleep habits than you may realize. [7] Getting adequate sleep—more than seven hours per night—is essential to helping your body recover and stay in tip-top shape.

5. Add an ashwagandha supplement

Ashwagandha can help reduce your cortisol levels. There is no magic pill, but this might push your levels to head in the right direction. Remember, if you start supplementing for a problem you do not have, you are not helping the root cause of your suffering and may create other problems. That's why you should consult your physician first.

Physical vs. emotional stress

While it is important not to push yourself over the edge, you should note where your stress comes from. Athletes usually complain of adrenal fatigue or "overtraining."

Stress can come from all areas of life, and it can be difficult for the body to identify which type it's dealing with. Knowing the difference is essential, especially if you are training for a big event.

Physical stress appears as:

  • Normal or optimized cortisol
  • Normal or high creatine kinase

Emotional stress does the opposite:

  • High or not optimized cortisol
  • Normal or low creatine kinase

Physical stress 

It can come from many avenues, but let's assume this stress comes from exercise. The wear and tear from pushing the body to new limits is the way to improve and work towards new goals. It is an acute type that is reduced with sufficient sleep, proper hydration, a diet rich in antioxidants, and rest days.

Emotional stress

This type of stress may be very subjective but can cause anxiety, depression, and poor sleep quality. We often put it upon ourselves, and it can become a chronic issue that can leave you emotionally and physically drained. It isn't just limited to traumatic events but can also come from negative self-talk.

Note: If physical and emotional stress appear together, we will see biomarkers that are all over the place. That would be a telltale sign that the brakes must be applied in training and life. 

High Cortisol InsideTracker

Optimized Cortisol InsideTracker

Why should you care about stress?

Many clients come in thinking they have adrenal fatigue or high cortisol when they may have chronically high creatine kinase, low iron, B12vitamin D, or just a perceived level of high stress and burnout. That's why checking your blood is essential.

Other clients have no idea that the internal stress from worrying is causing their bodies to respond with high cortisol and even completely disrupted blood glucose levels. They may end up bottling it up and putting the blame on themselves, avoiding the deeper.

Chronically elevated cortisol can lead to weight, immunity, and chronic disease issues. On the other hand, high CK can lead to muscle fatigue, injury, and decreased athletic performance. It is not something to guess or ignore. Take control of your stress and figure out the root of it all by testing today and monitoring over time.

» Discover science-backed ways to cope with stress

Chart your path to calm: proactive stress management 

You don't have to guess your anxiety levels. Biomarkers like cortisol and creatine kinase provide valuable insights. You should do blood testing and consultations with healthcare professionals to build a personalized roadmap for stress management.

A proactive approach is vital to optimizing health and achieving personal and professional goals. InisdeTracker's Ultimate plan can establish a healthy baseline for your biomarkers and provide actionable insights and expert guidance to achieve your goals and live healthier and longer.

InsideTracker doesn't treat or diagnose medical conditions. Consult your physician for any health-related concerns.


[1] S. L. King and K. Hegadoren, “Stress hormones: How do they measure up?,” Biological Research for Nursing, vol. 4, no. 2, pp. 92–103, Oct. 2002, doi: 10.1177/1099800402238334.

[2] M. K. Lee, E. Kim, and M. H. Choi, “Technical and clinical aspects of cortisol as a biochemical marker of chronic stress,” Journal of Biochemistry and Molecular Biology, vol. 48, no. 4, pp. 209–216, Apr. 2015, doi: 10.5483/bmbrep.2015.48.4.275.

[3] P. Brancaccio, N. Maffulli, and F. Limongelli, “Creatine kinase monitoring in sport medicine,” British Medical Bulletin, vol. 81–82, no. 1, pp. 209–230, Feb. 2007, doi: 10.1093/bmb/ldm014.

[4] “Effects of mindfulness meditation on serum cortisol of medical students,PubMed, Jan. 01, 2013.

[5] E. Childs and H. De Wit, “Regular exercise is associated with emotional resilience to acute stress in healthy adults,Frontiers in Physiology, vol. 5, May 2014, doi: 10.3389/fphys.2014.00161.

[6] J. Thirthalli, G. H. Naveen, M. G. Rao, S. Varambally, R. Christopher, and B. N. Gangadhar, “Cortisol and antidepressant effects of yoga,” Indian Journal of Psychiatry, vol. 55, no. 7, p. 405, Jan. 2013, doi: 10.4103/0019-5545.116315.

[7] C. Hirotsu, S. Tufik, and M. L. Andersen, “Interactions between sleep, stress, and metabolism: From physiological to pathological conditions,” Sleep Science, vol. 8, no. 3, pp. 143–152, Nov. 2015, doi: 10.1016/j.slsci.2015.09.002.