We all have our passions; our hobbies; the things we love to do.  For the most part, these are the things that make life enjoyable.  Hopefully, these things are also going to carry the added bonus of enhancing our quantity and quality of life.  This would be the ultimate win-win.


Running is a prime example of the aforementioned hobby, dare I say passion for some, maybe most of us.  There is the social aspect, the sense of community which draws many and drives awesome organizations like Space Coast Runners and the assortment of fun runs throughout the week.  There is the healthy competition, whether that be to place in your age group, or the battle against our biggest personal rival, the clock.  There is also the sense of accomplishment, achievement and reward, driven by that endogenous dopamine release that provides a well-deserved natural high.


However, it cannot be ignored that despite of all the positive aspects running may add to one’s life, it has the potential to be a detrimental physiological stressor.  Now don’t tune me out just yet.  It bears repeating that I too run.  I too do not just run, but I can honestly say that I love to do it (sometimes more than others), and attribute physical and mental benefits alike to it.  The point is that we should not allow ourselves to be blinded by love.  Just because we ignore something, doesn’t negate its existence or potential effects.  It’s true, ignorance can be bliss; that is until you are injured, suffering burn out or worse.


When it comes to running, studies have shown that the longer the duration, the more stress hormone output takes place.  We have briefly touched on these puppies before, but we are referring to the adrenal glands and the release of cortisol.  Whenever we are presented with a stressor in our life, be it chemical, mental or emotional, or physical, a similar cascade takes place within.  


An area in your brain called the hypothalamus perceives this message and sends a signal down to the master endocrine (hormone) gland, the pituitary gland.  The anterior pituitary then releases ACTH, which stimulates your adrenal glands (walnut sized glands mounted on top of your kidneys) to release cortisol to prepare for and combat a stressful event.



That is a basic overview of the stress response.  This doesn’t matter whether it is perceived or real, chemical or emotional, or, in our case, a physical. You see when we run, we are creating a stress reaction in our body.  Short term this is good.  This is one reason why HIIT (high intensity interval training) has become so popular.  There is science behind it.  It creates a short term, beneficial hermetic response in which, all sorts of goodness is enhanced like increased growth hormone, brain derived neurotrophic factor (repairs, regenerates and even grows to brain cells), the ability to burn fat for fuel, etc.  It does all this while limiting the potential detriments that come with a prolonged stress response.


Our bodies were designed to handle stress, but in the short term.  The cascade we spoke of above is wired as a negative feedback loop so that when things are working properly, the downstream release of cortisol from the adrenal glands, signals back to the brain and the hypothalamus that the job was done, all is well, and we can shut it down.  However, in the presence of a prolonged stressor, again real as in running a marathon, or perceived as in inner worry and angst about our job, money, relationships, etc., the stressor remains and the cascade of cortisol release is put into overdrive, negating the negative feedback loop.


So when you couple the stress we deal with on a day to day, from emotional to chemical (including and especially suboptimal diets), with a sustained physical stressor, we take a seemingly positive physical and perceived mental stress reliever like running and set the table for all that comes with this sustained activation of the afore described HPA (hypothalamus-pituitary-adrenal) and prolonged cortisol release.


So why is this bad?  It’s an interesting explanation and another fascinating example of how the holistic nature of the body works, but why should we care or even devote any space in our already occupied headspace to this?


First off, this isn’t simply theory.  The science is there.  As the steady state, consecutive miles add up, the release of cortisol is not only sustained, but increased. Think of how you build a muscle with frequency of repetitions.  It goes the same for other pathways in our body, including this neuroendocrine one.  The more it fires, the stronger it gets.  In this case we have unintentionally utilized the potentially positive concept of plasticity and hyper-facilitated our stress response.  Meaning it stays on longer and is harder to shut off.  Depending on your other stressors and how you cope, this can be a quite a harmful addition.


Many things can occur when the adrenals are over-active, including potential progression to fatigue and exhaustion.  For the sake of this discussion we will keep the list relatively shorter, but hopefully substantial enough to drive the point home.  First off sustained cortisol release increases our perception of pain.  And while it also has an initial anti-inflammatory effect (think about its downstream metabolite cortisone or its needle injected cousin hydrocortisone), it also dramatically dampens your immune system, making you prone to get sick.


Anti-inflammatory is generally thought of as a good thing.  And for the most part it is, but we also need mild inflammation as a healthy response to repair immanent damage from activities like exercises.  This is obviously a delicate balance with many factors playing a role, maybe none no greater than diet, but constant cortisol, means constant immune system suppression, means attenuated necessary immune mediated inflammatory response to help you heal, equaling delayed healing.


Your adrenal response and cortisol release is also highly time contingent and a regulator of your sleep wake cycle, or circadian rhythm.  Ideally, cortisol should peak in the morning about 30 minutes after waking up.  This has you up and ready to go.  It then should diminish throughout the day, concurrent with a slow inverse rise of melatonin, facilitating eventual sleep.  Constantly stressing throughout the day and causing a cortisol release can disrupt this rhythm.  Similarly that sustained release of cortisol mid or later day can also throw this delicate cortisol-melatonin dance off and is a main reason why many people have trouble sleeping when they work out later in the day.


(Another one also being the adrenal glands release of the central nervous system stimulator, nor-epinephrine.  This is why monitoring things like blood pressure and heart rate can be valuable indicators of whether or not you are in adrenal overdrive and need to tone down the fight or flight, sympathetic nervous system response with some intelligent, responsible rest and recovery.)


Once this hypothalamus – pituitary – adrenal (HPA) axis is hyper-facilitated for long enough, the balance necessary for optimal function is disrupted and other associated pathways start to suffer, and suffer dearly.  Increased intestinal permeability and disruption to gut micro biome as we spoke about two months ago, is a core issue.  We can see an initial increase in gastric acid secretion leading to heartburn.  Transport of glucose into the muscles is down regulated, leaving blood sugar levels elevated and a shift towards insulin resistance and damage from glycation.   The body senses it needs more energy in the form of glucose to deal with this stress, and begins to break down skeletal muscle. 


There is also the thyroid gland.  Hypothyroidism is extremely common in this country, and a contributing factor can be this HPA axis dampening its neighbor, the HPT (T=thyroid) axis.  This can create symptoms of or further exacerbate already existing hypothyroidism, regardless of the underlying cause of the thyroid dysfunction.


How about sex?  When the adrenals are constantly working to fire cortisol, a downstream hormone called DHEA can become dramatically inhibited.  DHEA is the precursor to our sex hormones, like testosterone and estrogen.  Less DHEA means less estrogen and testosterone.  Diminished DHEA, and subsequent DHEA supplementation has been associated with improvements in bone density in women, cognition and depression, and even lupus. 


Couple this low DHEA with the aforementioned overly up-regulated HPA axis now inhibiting the HPG (G=gonadal) axis (ovarian or testicular) and we even further androgen suppression.  This is pertinent information for those trying to conceive, approaching or going through menopause, and even the large population of men on testosterone based on one marker on one test (highly incomplete evaluation).  Before hopping on a potentially harmful synthetic or even biosynthetic hormone replacement, paths like these should be dutifully explored and addressed.


So how do you know if you are potentially overworking your adrenals, potentially at the expense of other seemingly unrelated, undeniably connected systems in the body? You can start with an adrenal stress index (ASI).  This is far superior to the serum cortisol level you may have done.  Number one, cortisol is released at different levels throughout the day, which means an observation of the rhythm is far superior and insightful than a one-time snap shot of a level, which as you can imagine can vary greatly depending on the time of day that the sample was collected.  Second, we need to look at free, unbound cortisol levels. This is tested by saliva, whereas the serum level includes bound and unbound cortisol, which further clouds the interpretation of results.  Lastly, we need to look up and downstream at precursors and metabolites (pregnenolone, DHEA, insulin, sig-A, etc.) to get the whole picture.  This is provided and then some by the ASI test. 



As you can imagine, in today’s stress filled world, we run this quite commonly in our office, along with complete male and female hormone panels; both of which can be done at home, with the patient providing timed saliva samples.  Feel free to reach out (321-848-0987; Dr.RClarke@gmail.com) if interested in exploring options with these or any other functional testing. 


Some common signs and symptoms associated with hyper or hypo adrenal function include, but is not restricted to:


Cannot stay asleep

Crave salt

Slow starter in the morning

Afternoon Fatigue

Dizziness when standing up too quickly

Afternoon headaches

Headaches with exertion or stress

Weak nails

Cannot fall asleep

Perspire easily

Under a high amount of stress

Gain weight when under high amounts of stress

Wake up tired even after 6 hours of sleep


This is nowhere near conclusive because, as we’ve stated, recognized and respect, the body does not exist in isolated systems, adrenals included.  Thyroid symptoms, digestive symptoms, sleep and hormonal issues, blood sugar dysregulation, and mental issues like depression and anxiety can all be linked to our caused by sustained prolonged stress and constant triggering of our HPA axis.


Treatment plans and approaches are always based upon test findings and personal history.  However, there are some basics we can apply in order to attenuate some of the potentially ill-effects of steady-state, high mileage cardio.  For reasons expressed earlier, we want to support the adrenal glands, upstream and downstream.  


We can start with taking HPA modulatory adaptogens.  These are simply powerful herbs that have an effect on proper communication from brain down to the adrenals and back.  Common players here include ashwaganda, holy basil, bacopa, cordyceps, rhodiola, Siberian ginseng, etc.  You can usually find these in isolation or in adrenal formulas.  Find one that works for you and take regularly, especially in times of increased stress; whether the stress is the kids, the bank account, the boss or peak in marathon training.



Also shown to be effective, particularly at reducing post exercise cortisol levels, which is right up our alley here, is phosphatidylserine.  Doses taken orally or applied topically after exercise or in the afternoon and evening have been shown to calm down elevated cortisol levels.


One that I personally have been implementing lately, along with an adaptogenic formula, has been the amino acid L-theanine.  This is the precursor to the inhibitory neurotransmitter GABA and while it doesn’t directly modulate the adrenals, it does lend itself to increasing GABA levels.  GABA is necessary for proper sleep (which is when our bodies do their best repair work on those pesky running injuries), is anxiolytic, and elevations lead to a calming and relaxing effect.  


It should be noted that the point if this article is to no way, shape or form deter one from running.  It is quite the contrary. The point is to elucidate physiological fact and subsequently act upon this knowledge in order to continue to do what you want to do, what you love to do as long as you want.  It is to be aware of the real potential issues this great activity can lead to, especially when coupled with the rest of our more than likely life of stressors, and to be proactive in all the other areas to support a healthy response, a better life, and a longer running career, on your terms.


It comes as no surprise than that in addition to targeted supplemental support, lifestyle changes should be made wherever possible.  This goes beyond running, but as we’ve hopefully demonstrated can prove beneficial on this front as well.  We all have our limits.  We all have different starting points and different sized cups, if you will.  As we go through life that cup begins to fill with various toxins, including the ill-effects of stress.  Once it reaches capacity, and the cup overflows, we suffer burn out and more severe pathology.  We want to do all we can to decrease the toxic burden, to decrease our stressors in order to prevent the cup from overflowing, the straw breaking the camel’s back, the barefoot run that led to the plantar fasciitis; no? Anybody? Well, you get the point.


This is why a healthy diet, healthy relationships, working towards mastering oneself through mindfulness or meditation is not just loosely recommended, it is vital for to optimally handle and limit the cup filling system stressors, especially as we age, and especially as we continue to get those miles in.


As always, take care of yourself out there and keep doing what it is you love to do.  That’s what it’s all about.  Don’t turn a blind eye to what is now a firm grasp on the inner workings of our physiology, especially when it comes to stress.  If you need help or guidance identifying your particular issue, and would like assistance in formulating an intelligent, long term plan, I’m ready when you are.

Be well.

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