Running and Cortisol Levels: What You Need To Know
Whether you realize it or not, serious training affects your hormonal (or endocrine) system. And while the role of some hormones, like insulin, is generally more well known and better understood by the general public than others, each of these impacts are important.
Professor Anthony Hackney, co-author of the 2nd edition of the book Sports Endocrinology, warns, though, that a little bit of knowledge on the subject can be dangerous. Because while the body’s endocrine system is a highly complex and interlinked one, many athletes try to artificially interfere with only one or two of its components. Which could lead to disastrous health impacts in the long run.
One of the lesser known, but very important, components of the endocrine system, is cortisol. Generally perceived in a negative light as a result of its association with stress and potential weight gain, this hormone actually plays a vital role in helping your body increase its physical fitness. So here’s everything you need to know about the link between cortisol and running.
What is cortisol?
Cortisol, a catabolic and anti-inflammatory hormone, is produced and secreted by the adrenal gland after being triggered to do so by the hypothalamus. And, just in case your biology is a bit rusty, the hypothalamus (located below the thalamus) is the major controller of metabolism in the human brain.
So what exactly causes the hypothalamus to instruct the adrenal gland to produce cortisol? In short, stress. And while cortisol is often perceived in a negative light because of this, it’s important to remember that the body’s ability to react to stress is vital in terms of both health and survival. So how does the process work? In a nutshell, the body detects a stressor and releases cortisol to help it deal with said stressor. How? By a) boosting blood sugar levels to provide energy for dealing with the stressor, and b) by putting the body’s reproductive and digestive systems on the back burner until the stressor has been dealt with. After the stressor disappears, cortisol levels go back to normal and the body goes back to a homeostatic state. And while this happens in everyday stressful situations, the process is even more significant to us as runners. Why? Because improvement in physical fitness through training is also a type of stress response.
In short then, the effect of cortisol on the body is necessary and fundamentally beneficial. But unfortunately, that’s not where it ends. How so? Because the effect of cortisol can become negative if you’re subjected to too much stress on an ongoing basis.
Why is it important to keep cortisol levels in check?
So what exactly happens when the body is chronically under stress? Basically, instead of returning to normal, cortisol levels remain elevated. Which, in turn, could potentially lead to a number of long-term negative health impacts. This includes abdominal fat gain, a compromised immune system, and cognitive decline.
Running and high cortisol levels
The bad news for runners, even those who keep their daily home– and work stress levels in check, is that the repeated, short bursts of cortisol release associated with running have been found by some to be equal to long-term high cortisol exposure.
A 2012 study published in Psychoneuroendocrinology, for example, used hair segment analysis to compare cumulative cortisol secretion over several months between 304 amateur endurance athletes and 70 controls. The research team found that “endurance athletes exhibited higher cortisol levels in all three hair segments compared to controls”, leading them to conclude that the “repeated physical stress of intensive training and competitive races among endurance athletes is associated with elevated cortisol exposure over prolonged periods of time”.
So does this mean that endurance running is bad for your health in the long term? Not necessarily. How so? Because the ability of running to improve brain function, aid weight management and enhance immune function has been proven many times over. Which, in itself, shows that the impact of high cortisol levels in runners appear not to be similar to that on non-athletes.
Too much of a good thing
There is, however, an exception. If you overtrain, constantly high cortisol levels may, in addition to a number of other hormonal imbalances that commonly occur in the bodies of over-trained athletes, contribute to various negative health impacts. This includes general fatigue, inability to sleep, a raised resting heart rate and acute muscle soreness.
It is therefore always a good idea to, from time to time, step back and take an honest look at your training. Or, alternatively, to get an honest opinion from someone that you trust. Is your body able to keep up with your training? And is running contributing to your quality of life in general? If not, it may be time to ease off a little.
How to help your body deal with stress
And while there isn’t much you can do about the impact of a balanced running regime on cortisol levels, there’s plenty you can do to help your body deal with stress. This includes:
- Mindfulness and meditation. Try to take some time each day to slow down, sit in silence and focus on only one thing. Not only can this strengthen neural pathways, but it can also help calm the nervous system.
- Getting enough sleep. A lack of enough, quality sleep directly impacts the brain’s ability to function and causes cortisol levels to rise.
- Watching what you eat. Yes, we know you know. But avoid refined carbs and too much alcohol. It doesn’t do your body any favors.
- Not overtraining. Rest and recovery is your friend, not your enemy.
So do what you can to listen to your body and treat (and train) it with respect. Rest enough, recover properly and fuel wisely. And also make an effort to keep your general stress levels in check. But other than that, if you’re a healthy runner with no health issues of note, don’t lose too much sleep over cortisol. Train and live smart and your body will do the rest.
- What is cortisol, and should you be worried about it?, Online publication, Jul 31, 2014 ,
- Cortisol Switcharoo: How the Main Stress Hormone Makes You Fat and Angry, Online publication, Jun 18, 2012 ,
- 5 Ways to Reduce Cortisol, the Stress Hormone Responsible for Belly Fat, Online publication, Sep 15, 2017 ,
- The role of hormones in running, Online publication, May 15, 2014 ,
- Elevated hair cortisol concentrations in endurance athletes, Scientific journal, May 01, 2012 ,