[Editor’s Note: This month’s Trail Sisters article is penned by Pam Smith, an M.D. who is board certified in Anatomic Pathology, Laboratory Medicine (Clinical Pathology), and Hematology. She claims no personal expertise on Ecstasy.]
Ultrarunners are a group who have embraced the mentality of ‘more is better:’ more miles, more vert, more gnarly terrain, more races. But in the last few years there have been increasing information and personal stories about the downsides of extreme running–things like fatigue, poor performance, and lack of motivation. I think it is important to acknowledge the detrimental effects of running so that we can all better recognize the warnings and minimize these occurrences. Not uncommonly, the term ‘adrenal fatigue’ is used in these discussions.
‘Adrenal fatigue’ seems to be a more popular vernacular phrase than the alternative title, ‘overtraining syndrome (OTS).’ I think overtraining syndrome may be less appealing to some people because it has subtle connotations of blame: This happened to you, because you overtrained; whereas adrenal fatigue sounds more like a disease that is just a matter of bad luck. I also think some people shy away from the term OTS because it can have its onset when training hasn’t changed or when mileage has even decreased, such as if a person is racing a lot or has a lot of other stressors in their life. The term overtraining syndrome is preferable to adrenal fatigue for many reasons, but most importantly because it is misguided to blame all symptoms of fatigue and performance decline on poor adrenal function. No matter what one calls this phenomenon, I do believe exercise-induced malaise is a real entity and in no way am I trying to dismiss anyone’s experiences or the symptoms they have had.
In this article I plan to give a brief overview of the origin of the term adrenal fatigue and problems with the definition, an overview of adrenal biology, potential causes of fatigue besides adrenal dysfunction, and the role of laboratory testing in assessing adrenal function.
ORIGINS OF ‘ADRENAL FATIGUE’
The term adrenal fatigue was popularized by James L. Wilson in his 2001 book Adrenal Fatigue: The 21st Century Stress Syndrome. Wilson is certainly a well-educated man with masters degrees in nutrition and experimental psychology, a Ph.D. in nutrition, as well as degrees in chiropractic and naturopathic medicine, but he has no training or expertise in human physiology or endocrinology. Wilson maintains that chronic ongoing stress depletes the adrenal glands and causes decreased output of adrenal hormones, particularly cortisol. He states that modern medical doctors do not recognize this condition because there is no pharmaceutical agent to treat it and thus no money to be made by physicians, and that laboratory tests aren’t sensitive enough to detect this problem. Wilson offers no evidence that any of his anecdotal patients actually have abnormal adrenal function other than the symptoms which he has used to define adrenal fatigue. In the past 15 years, numerous additional naturopathic sources have written books and web content on adrenal fatigue, further promoting use of the term to describe a collection of symptoms, still without direct validation of adrenal malfunction.
There are several problems with the arguments Wilson gives. Adrenal fatigue is not a medically recognized condition; however, Western medicine can detect low adrenal function. In 2013, Katie Grossman (née DeSplinter) was having crushing fatigue that was affecting her ability to work and train. Additionally, she had several odd kidney infections. While she did have to advocate for herself some, a 24-hour urine test of cortisol levels showed mildly low cortisol levels. Doing spot testing of cortisol levels at different times of the day revealed low afternoon values and Katie was diagnosed with “impaired adrenal function.” It is true that Western medicine doesn’t offer much of a solution for this, but I don’t believe doctors won’t diagnose it because it doesn’t make them money. First off, by the Stark Law, it is absolutely illegal for physicians to make money off of drugs they prescribe, and taking any kickbacks from a pharmaceutical company could result in fines, loss of licensure, and even jail time. Second, Family Practice docs and Internal Medicine docs make a significant portion of their income from office visits, so not having a drug to prescribe would not affect this. And most importantly, I believe that most physicians have altruistic motives and genuinely want to see people get better, even if it means giving a diagnosis that is not ‘lucrative.’ Despite the claim that there is no money to be made from this diagnosis, Dr. Wilson has created and markets his own adrenal supplement and even includes two full-page ads promoting its use in his book. Most of his anecdotes end on a happy note with a phrase like “after making lifestyle changes and taking supplements she got better” or “the patient followed all my recommendations (which includes an adrenal supplement) and made a full recovery.” The supplements sell for $67 for a bottle of 150.
Not all naturopaths agree with Wilson, so this is not just a Western-medicine versus alternative-medicine quarrel. Dr. Philip Maffetone, a well-known endurance author and doctor of chiropractic medicine, views overtraining as imbalances in the hormonal, neurological, emotional, and muscular systems. He believes all but the most severely affected athletes have increased cortisol levels. He does not make use of the term adrenal fatigue in his 516-page The Big Book of Endurance Training and Racing, much of which is dedicated to avoiding and treating training related fatigue.
But the biggest problem with Wilson’s theory is that his explanation doesn’t mesh well with scientific literature in the area of overtraining syndrome. Fully two thirds of people with symptoms of OTS show no abnormalities of adrenal function. Of those that have abnormal cortisol levels, the overwhelming majority actually have increased cortisol levels, leaving only 10% of all overtrained athletes with decreased cortisol levels. Symptoms of overtraining certainly merit evaluation of adrenal function, but it is misguided to jump to the conclusion that the symptoms must be caused by low adrenal output.
The adrenal glands are crescent-shaped endocrine organs weighing seven to 10 grams and sitting directly above the kidneys (ad=next to; renal = kidney). The adrenal gland has two main parts: the outer section, or cortex, and the inner medulla. The cortex is responsible for producing mineralocorticoids, glucocorticoids (predominantly cortisol), and androgens. These help regulate electrolyte levels, affect blood-glucose levels, and serve as precursors for sex hormones, respectively (“Salt, Sugar, Sex” as the med-school mnemonic goes). The medulla produces epinephrine and norepinephrine (aka adrenaline and noradrenaline), hormones that are involved in acute stress situations, or the “fight or flight” response.
Because discussions of adrenal fatigue and overtraining focus on cortisol, that’s what we will focus on here, too. Cortisol levels vary throughout the day, corresponding to our expected activities. Cortisol peaks in the mornings which mobilizes glucose and helps us be ready for the activities of the day. Cortisol levels drop throughout the afternoon, allowing us to wind down and be ready for bed. The lowest levels occur three to five hours after the onset of sleep, corresponding to a shutdown of activity and the state of deep rest. However, it is important to know that cortisol secretion is actually not controlled by the adrenal gland itself, but rather it is regulated by the hypothalamic-pituitary Axis (ie. our brain). To simplify this as much as possible: our eyeballs take in information about how much daylight there is and send it to the supraoptic nuclei (“brain region above the eyes”). This in turn sends signals to the hypothalamus, the portion of the brain that is responsible for translating neural signals into hormone signals, and it in turn sends signals on to the pituitary. The hypothalamus can also get other messages from the brain (“Stress!”) which causes it to signal the pituitary. The pituitary then sends ACTH (adrenocorticotropic hormone, basically, the “cortisol release signal”) to the adrenal gland.
The take-home message in all of this is: your brain is actually responsible for how much cortisol is released, not your adrenal glands.
Think of the adrenal gland like a 10 year old with a chore list. A 10 year old is more than capable of doing chores but isn’t going to them without being told by a superior, such as a parent. But if the parent doesn’t tell the child to do the chores, they aren’t going to get done on the child’s own will–at least not in my house anyway! If I don’t tell my son to do the dishes and they don’t get done, I don’t assume it is because my son broke both arms! The adrenal glands are the same way. They are basically just obeying orders from the brain and not making independent decisions. This is one reason I think adrenal fatigue is a misnomer. Most alterations in adrenal-hormone levels are due to outside factors and changes in signals to the adrenal gland, but the gland itself is perfectly fine. It’s not the adrenals’ fault! If the adrenal glands fail to respond to the brain signals, a person is usually very sick and this is most often associated with severe damage to the adrenal gland, such as from an autoimmune disease, infection, or trauma. If the adrenal gland does secrete hormones autonomously, it is overwhelmingly due to an adrenal tumor.
OTHER CAUSES OF FATIGUE
Before jumping to a conclusion of overtraining syndrome or adrenal fatigue, athletes should first consider other causes, particularly ones that are especially common.
The one that comes up most often in my mind is post-event fatigue. Running an ultra is hard! It is an acute stress on your body, not to mention they cause a lot of direct physical damage. A study after Western States showed that the finishers had an average CPK level (a marker of muscle damage) of 10,000 U/L (normal <200). The medical community defines rhabdomyolysis as severe muscle damage with CPK levels over 5,000 U/L (not to be confused with renal failure). Studies on rhabdomyolysis in the medical literature have shown that it takes seven to 10 weeks for muscles to fully repair.
Ultrarunning also causes a lot of inflammation and inflammatory signals, called cytokines. Cytokines have the effects of increasing fatigue and decreasing motivation. (Think of how you feel with a fever, a condition associated with very high cytokines.) But don’t think just because your soreness has gone away, that the inflammation is gone. Cytokines will remain elevated until all damaged muscle has been removed, typically 10 to 12 days.
Changes in neurotransmitter levels also accompany a big event. In some ways, running an ultra is like using the drug Ecstasy, at least in terms of changes in brain neurochemistry. Don’t things like euphoria, increased sociability, increased feelings of closeness with others, a sense of inner peace, mild hallucinations, enhanced sensations, or an altered sense of time remind you of things you have felt during an ultra? But that is actually a list of Ecstasy effects! Both hard physical activity and Ecstasy cause increased levels and decreased re-uptake of serotonin, dopamine, and norepinephrine in the brain. Ecstasy is often associated with a post-use ‘haze’ consisting of depression, tiredness, lethargy, irritability, and loss of focus that can last for two weeks or more (“the Molly hangover”) while the brain neurotransmitters re-balance. It makes sense that a similar haze would result after a hard physical effort as well.
Lastly, the medical definition of overtraining syndrome requires that symptoms persist after 21 days of complete rest (less than this would be defined as some type of overreaching). How many ultrarunners ever do this after a big event? For all of these reasons, if you are less than a month out from your big event, OTS (and adrenal fatigue) shouldn’t even be part of the conversation. Instead, tell people you have post-event fatigue or that you are still recovering from your last race.
Another possible cause of fatigue is chronic sleep deprivation. The National Sleep Foundation recommends seven to nine hours of sleep for most adults, though in several studies where subjects are “left to their own devices” to determine sleep habits, the participants slept eight hours or more. And people engaging in heavy physical activity actually need more sleep in order to facilitate recovery. Several studies on Stanford University athletes showed improved sports performance after 10 hours of sleep in multiple types of sport. These effects are so striking that a few articles have called sleep “a secret weapon in sports” and “the new Gatorade.” Alan Webb said the most important change he made to his training when he set the one-mile American record was getting at least 10 hours of sleep per night. Kara Goucher aimed for 10 to 12 hours of sleep while training for the New York Marathon, and Serena Williams has claimed she routinely goes to bed at 7 p.m. to get enough sleep. But most of us aren’t professional athletes and we don’t have the luxury of getting that kind of rest. If you are like me, a heavy-training block can actually mean less sleep as you try to fit the training in with all your other activities. And while lots of sleep can boost performance, sleep deprivation can do the opposite. Even with six hours of sleep a night, athletic performance can suffer. Lack of sleep increases cortisol levels, decreases glycogen storage and mobilization of carbohydrates, decreases muscle recovery, decreases cardiovascular function, and decreases muscle strength. Even Wilson advocates for 10-and-a-half hours of sleep as a part of the cure for adrenal fatigue. While it is unreasonable for most of us to aim for 10-plus hours of sleep, if you are feeling overly tired, it is important to be honest about your sleep habits and maybe skip a few workouts or other obligations to catch up on some sleep.
Nutrition is another big one. Not getting enough calories and specifically not enough carbohydrates can cut into performance. Periods of starvation and insufficient calories increase stress and cortisol levels. Carbohydrate consumption decreases cortisol. This is not to say that high-fat-low-carb eating has no place in training. Indeed, the philosophy of training is to create stresses to induce a beneficial adaptation. However, if you feel your training is suffering for an extended period of time, you may need to focus on adding in more carbohydrates. Amenorrhea in female athletes is tightly correlated with insufficient calories. A history of stress fractures in men and women should also warrant a look at one’s nutrition with a critical eye.
Lastly, it is important to rule out specific medical causes. One study showed that more than half of athletes with symptoms of overtraining had an underlying medical condition. The most common was viral illness and other infections, but admittedly, these can be hard to detect without sophisticated laboratory testing. Other possibilities include vitamin and mineral deficiencies, hypothyroidism, and other chronic diseases. In 2014, I began having many symptoms of overtraining, such as shortness of breath, achy legs, and lack of motivation, only to discover all the symptoms were related to asthma. Another friend of mine had all kinds of training problems before being diagnosed with celiac disease.
Blood testing is extremely sensitive for detecting cortisol levels and can detect values down to 0.05 mcg/dL. That’s .05 micrograms. It’s also 40 times lower than any expected normal value. The test can detect changes of 0.1 mcg/dL, meaning it can tell the difference between 2.4 and 2.5 and is very good at tracking any changes a patient has in their values. The downfall to the test is that there is a very wide range of normal, so one-time testing may not have much meaning. Wilson spends a whole chapter of his book discrediting blood testing in favor of salivary testing, based on how the reference ranges are set up, seemingly oblivious to the fact that the reference ranges for salivary testing were established in the exact same way. However, it is true that salivary testing shows good correlation with blood testing and is a useful alternative. Salivary testing can be more convenient for a patient because it can be done at home and it may also avoid the acute stress of a needle stick which could affect results. That being said, I wouldn’t rely on either one to diagnose adrenal insufficiency. A 24-hour urine test will show how much cortisol your adrenals produce in a day and give you an idea if they are at least producing the right total amount. But the most specific test is an ACTH (adrenocorticotropic hormone) stimulation test. This test measures baseline cortisol and then a dose of releasing hormone is given and subsequent cortisol levels are periodically measured and compared to the baseline. If the cortisol levels increase normally, it shows your adrenals are capable of responding to input appropriately and that there is nothing wrong with the adrenals themselves, hence excluding the possibility that the adrenals are too fatigued to make cortisol. The best thing about this test is that values are compared to your own baseline, so they are more specific to you. (The change in value is tracked, not the absolute values.)
On another note, I recently received a spam email for monthly cortisol hair testing. Hair testing is good for assessing what your average cortisol levels have been over a time frame of one to two months. In research it has primarily been used to see how long-term stressful situations (such as poor living conditions or chronic disease) affect stress hormones. The problems with hair testing are that it doesn’t change very quickly and it doesn’t tell you where you are currently so you can’t tell how recent changes have affected you. And as we have noted before, the majority of overtrained athletes don’t have cortisol abnormalities. I feel this company is feeding on the fears of endurance athletes and I would not recommend this service.
Overtraining syndrome is a multifactorial process, without a single identifiable cause. While cortisol testing is very helpful for assessing adrenal function, it really doesn’t help much in the overall diagnosis of OTS. The diagnosis requires a thorough medical evaluation along with a detailed history from the athlete. Likewise, the best preventative measure is a diary or training log which addresses simple questions such as: How well did you perform versus your expectation? How is your motivation and mood? How sore are you? How tired do you feel during the rest of your day? Three or more days in a row where things don’t go well, particularly if they don’t improve or are getting worse, should be a red flag to take things easy for a bit.
THE DANGER OF ‘ADRENAL FATIGUE’
I’ve tried to give reasons why the term adrenal fatigue is not an accurate term to use, but perhaps you are thinking, What difference does it make what we call it? To some degree that is true and Western medicine has several terms that are misnomers: a ganglion cyst has nothing to do with nerve ganglia, nor is it a true cyst; a pyogenic granuloma is not an inflammatory lesion but rather a hemangioma. But automatically assuming your fatigue is due to adrenal malfunction has the potential to miss some other cause, as I have already discussed, but beyond that there are a couple of recommended treatments for adrenal fatigue that I would caution against. One is adrenal-cell extracts. Active adrenal extracts have hormone activity and suppress normal adrenal function by sending errant signals to the body that it already has enough hormone and doesn’t need to make more. This is true of other adrenal replacements as well, such as cortisol, prednisone, and DHEA. Dr. Wilson’s Adrenal Rebuilder is made from pulverized pig adrenals that have been processed to inactivate the hormones. He claims that these extracts contain all the building blocks of adrenal glands to better promote and restore adrenal health. This is like telling a person with emphysema to eat lung tissue or a person with a gastric ulcer to eat haggis and tripe. Unlike pharmaceuticals, supplements don’t have to prove effectiveness and are not subject to any government regulations in the U.S. While the inactivation process means they won’t suppress adrenal function, their use will likely be detrimental to your wallet with no proven health benefit.
Dr. Wilson also states that people with adrenal fatigue have low gastric acid and problems with digestion, and should take a hydrochloric-acid supplement. While this is generally safe for most people, there are risks. Acid supplementation can increase the symptoms of reflux and it increases the risk of gastric ulcers. If you have a history of reflux and gastric ulcers, or you take NSAIDs, you should not use acid supplements.
The remainder of Dr. Wilson’s suggestions read like common-sense good-health practices that are likely to help people feel better no matter what the underlying cause of fatigue. These include getting lots of sleep, cutting out processed foods (though he does encourage eating lots of starchy foods and whole grains), removing alcohol and caffeine, going by “feel” for workouts and stopping when it feels strained, and removing major stressors from one’s life–all things that I think most people would agree are good for overall well being. (Well, not everyone will agree to the caffeine and alcohol part!) Katie Grossman quit her stressful job at a company she hated, stopped taking birth control, cut back on training, stopped racing entirely, and focused on sleeping as much as she could every night. She did not take any special adrenal supplements. Katie says she is still not sure what really helped her, but after seven to eight months she was feeling better.
- Overtraining syndrome is a real entity and the symptoms can have a major impact on a person’s life.
- Most OTS cases have no alteration in cortisol levels.
- When cortisol and adrenal hormones are off, it is not because the adrenals are ‘tired’ or ‘too weak’ but rather it is due to external factors which alter the signaling to the adrenal glands.
- Lab testing is very sensitive and reliable for measuring cortisol levels. However, an ACTH stimulation test will usually yield more useful information than a blood or salivary test. I do not recommend hair testing.
- Fatigue has many different causes and assuming it is due to poor adrenal function may result in a missed or delayed diagnosis of the real cause. Some supplements recommended to treat adrenal fatigue may actually be detrimental to your health.
- If you do think you may have OTS, it is a good idea to first talk to a medical professional to rule out any underlying causes for your fatigue. If OTS does seem like a possibility, the mainstay of treatment is a break from all training. Light activity is acceptable, but it should be guided by how you feel and not have any specific goals (like time or pace) until you are feeling recovered. Good sleep and nutrition habits are always encouraged for people suffering from fatigue.
[Editor’s Note: Joe Uhan wrote a three-article series on overtraining syndrome on iRunFar. Part One is an overview of the medical condition. Part Two addresses treatment and prevention. Part Three applies OTS to ultrarunning.]
CALL FOR COMMENTS (FROM MEGHAN)
- Have you received a medical diagnosis of overtraining syndrome or do you have symptoms of it? Can you describe your symptoms?
- For those addressing fatigue and endurance-performance-based health issues, have you identified stressors that may be contributing to your issues? For instance, training volume, training intensity, sleep, nutrition, work, family, finances, and more?
- Do you think that separating overtraning syndrome and adrenal fatigue in our community’s conversation about endurance-running health issues as Pam does with this article can help progress our understanding and discussion of endurance-running health?