Overtraining Can Decrease Your Immune Function and Tax Your Adrenals

Story at-a-glance -

  • Near-daily moderate-intensity physical activity benefits your immune function, decreasing the number of sick days by as much as 50 percent. Sustained and intense exertion tends to have the converse effect
  • Athletes who overtrain are susceptible to respiratory infections, and may need nutritional support to avert this immune function breakdown. Nutritional yeast has been shown to be very effective for this
  • Overtraining can also tax your adrenals and contribute to adrenal fatigue, and may play a role in the development of polycystic ovarian syndrome — especially if you undereat, overtrain, and fret about your physique

By Dr. Mercola

A number of lifestyle factors can contribute to poor health and early death. Perhaps one of the most pernicious is stress, which can be either mental/emotional, or in the case of athletes, excessive physical stress from overtraining and lack of recovery.

Research shows that near-daily moderate-intensity physical activity benefits your immune function, decreasing the number of sick days by as much as 50 percent. Overdoing it with sustained and intense exertion, however, tends to have the converse effect.

Acutely, stress temporarily suppresses parts of your immune system, thereby rendering you more vulnerable to pathogens and other foreign invaders.

As noted by Dr. Michael Greger in the video above, athletes who overtrain can become susceptible to respiratory infections, and may need nutritional support to avert this immune function breakdown.

Your best bet is to make sure you sufficiently recover between workout sessions, of course, but if the damage is already done, dietary supplements like nutritional yeast may help get you back in the game faster.

Overtraining can also tax your adrenals and contribute to adrenal fatigue, which needs to be addressed in order to preserve your health. Polycystic ovarian syndrome (PCOS) is yet another adrenal-related condition that can be triggered or worsened by excess mental and physical stress.

The Benefits of Nutritional Yeast

As described by Greger, under normal circumstances heavy exertion results in a dip in circulating monocytes — white blood cells that act as your body's first line defense against invaders.

However, athletes who ate 3/4 of a teaspoon of nutritional yeast per day ended up having higher amounts of circulating monocytes two hours after intense exercise — higher in fact than their pre-workout numbers, which is quite surprising.

To assess whether this actually translates into fewer illnesses, researchers tested nutritional yeast on marathon runners. Compared to placebo, the runners who ate nutritional yeast cut in half the number of days they were sick over the following two plus weeks after the race.

Those who took nutritional yeast also reported feeling better, both physically and emotionally, compared to the placebo group. The treatment group reported feeling less fatigued, less confused, less angry, and less tense. They also reported significantly increased vigor.

Nutritional Yeast — A 'Superfood' High in B Vitamins

Nutritional yeast is an excellent source of B vitamins, especially B6, but also B12, folate (B9), thiamine (B1), riboflavin (B2), niacin (B3), and pantothenic acid (B5).1 One serving (2 tablespoons) contains nearly 10 milligrams (mg) of vitamin B6, and nearly 8 micrograms (mcg) of B12.

It's also a good source of protein, dietary fiber, magnesium, copper, manganese, and zinc. I love the taste of nutritional yeast and personally take a tablespoon with most meals. It is the highest food source of B vitamins that are important for mitochondrial health.

Not to be confused with Brewer's yeast or other active yeasts, nutritional yeast is made from an organism grown on molasses, which is then harvested and dried to deactivate the yeast. 

It has a pleasant cheesy flavor and can be added to a number of different dishes.2 I also take 1/8 teaspoon a day of Nutritional Yeast in my smoothie to help optimize my microbiome.

Is Poor Body Image Wreaking Havoc With Your Hormones?

Stress can also be a factor in polycystic ovarian syndrome (PCOS), a condition caused by elevated androgens, i.e. male sex hormones, which can affect a woman's menstrual cycles, fertility, weight, and more.

This may be especially true if you undereat and overtrain to improve your physique, you don't have cystic ovaries, and your weight is normal or below normal and you do not struggle with insulin resistance. As noted in an article by dietitian Laura Schoenfeld:3

"I've worked with dozens of women who were undereating, overtraining, and under constant stress and even fear related to their poor body image and a desire to be thinner and leaner by any means necessary.

Sadly, this extreme diet and exercise behavior can backfire when women start to develop 'adrenal PCOS:' the elevation of androgenic hormones by the adrenal glands that causes symptoms similar to ovarian cyst-driven PCOS."

How Chronic Stress Can Elevate a Woman's Male Sex Hormones 

Schoenfeld goes into far greater detail on the hormonal cascade that can trigger PCOS, but in summary, stress triggers your body to produce a number of hormones, starting with adrenocorticotropic hormone (ACTH), which stimulates your adrenal glands to produce stress hormones such as cortisol and adrenaline.

ACTH also triggers the production of adrenal androgen hormones, including androstenedione, which is one of the two primary androgenic hormones causing PCOS symptoms in women.

It has been my clinical experience that insulin resistance plays a major role in PCOS, and that restriction of nonfiber carbs to less than 50 grams per day, and a moderate protein intake of 1 gram/kilogram of lean body mass, can dramatically help. Nevertheless, stress also plays an important role.

As noted in the article:

"[W]omen who are under chronic stress not only have more opportunities for elevated ACTH and thus elevated androgens, but their hormones may also start to react more severely to stressful situations. Don't get me wrong: there are plenty of women whose PCOS is caused by a poor diet, inadequate exercise, too many refined carbohydrates and sugars, and a generally unhealthy lifestyle.

But if you're breaking your back trying to follow the perfect low-carb Paleo diet, going to CrossFit five to six days per week, and finding yourself gaining weight, losing your menstrual function, growing hair in weird places, developing adult acne ...

[O]r simply feeling like a truck hit you every morning you wake up, it may be chronic stress causing your physical symptoms and hormonal imbalances."

Stress and Adrenal Fatigue

Chronic overexertion can take a tremendous toll on your health. As described by Elinor Fish in a previous Huffington Post article,4 as an avid runner she was surprised when she suddenly developed persistent fatigue and mood swings. After struggling for four years, she was eventually diagnosed with adrenal fatigue.

Your adrenal glands, located just above each of your kidneys, are responsible for one of the most important functions in your body: managing stress, and when they become taxed or exhausted your entire body feels it and suffers from extreme exhaustion as well.

As noted by Dr. Michelle Eads: "Adrenal fatigue is a huge issue in our fast-paced society where people wear their busy-ness like badges of honor. The symptoms of adrenal fatigue are so prevalent ... that they've become the 'normal' way to live." While adrenal fatigue can be notoriously difficult to diagnose unless or until your health has significantly deteriorated, tell-tale signs include:

Trouble staying asleep through the night, or trouble waking up in the morning, despite a full night's sleep

Inability to improve your fitness; getting increasingly tired rather than fitter when exercising

Feeling "wired but tired," and craving naps in the afternoon

Weight gain

Low energy; frequent fatigue

Anxiety and/or depressed mood

Decreased motivation to exercise

Decreased ability to handle stress; frequently feeling overwhelmed by minor stressors or everyday life

Depressed immune function

Muscle weakness

Cravings for foods high in salt, sugar, or fat

Skin problems

Decreased libido

Lightheadedness when getting up from sitting or lying down

Poor memory

Worsening PMS or menopausal symptoms

The Importance of Healthy Adrenal Function

Your adrenal glands secrete more than 50 hormones, many of which are essential for life and include:

  • Glucocorticoids. These hormones, which include cortisol, help your body convert food into energy, normalize blood sugar, respond to stress and maintain your immune system's inflammatory response.
  • Mineralocorticoids. These hormones, which include aldosterone, help keep your blood pressure and blood volume normal by maintaining a proper balance of sodium, potassium and water in your body.
  • Adrenaline. This hormone increases your heart rate and controls blood flow to your muscles and brain, along with helping with the conversion of glycogen to glucose in your liver.

Together, these hormones and others produced by your adrenal glands control such body functions as:

  • Maintaining metabolic processes, such as managing blood sugar levels and regulating inflammation
  • Controlling your "fight or flight" response to stress
  • Producing sex steroids such as estrogen and testosterone
  • Regulating your body's balance of salt and water
  • Maintaining pregnancy

Common Factors That Stress Your Adrenals

Although your adrenal glands are there in large part to help you cope with stress, too much of it is ultimately what causes their function to break down. When your adrenal glands become depleted, it leads to a decrease in certain hormone levels, particularly cortisol.

The various hormone deficiencies will vary with each case, ranging from mild to severe. Its most extreme form is known as Addison's disease, a potentially life-threatening condition that causes muscle weakness, weight loss, low blood pressure and low blood sugar.

At the other end of the spectrum, as well as in between, lies adrenal fatigue (also known as hypoadrenia). Though the symptoms are less severe than in Addison's disease, symptoms of adrenal fatigue can still be debilitating. Common factors that put excess stress on your adrenals include:

Anger, fear, anxiety, guilt, depression and other negative emotions

Overwork, including physical or mental strain

Light-cycle disruption (such as working the night shift or often going to sleep late)

Chronic inflammation, infection, illness or pain

Nutritional deficiencies and/or severe allergies

Excessive exercise

Sleep deprivation

Surgery, trauma or injury

Temperature extremes

Toxic exposure

How Can You Diagnose Adrenal Fatigue?

There are a wide variety of ways to measure adrenal function. The most common are a 24-hour urine, timed collections or a blood draw. Each of these have some serious drawbacks, which is why I have determined that for most people a timed urinary collection is the most efficient and best way.

One simply urinates on a strip at four specific times in 24 hours and then lets the strips dry and send them to the lab for analysis. The test results come back with a very comprehensive analysis and colorful graphics. The test can be obtained at dutchtest.com. It's what I use to check my own adrenal function.

Should You Exercise If You Have Adrenal Fatigue?

It's important to recognize that it takes time to recover from adrenal fatigue. For minor adrenal fatigue, you can expect a recovery time of about six to nine months. For severe adrenal fatigue your recovery time may be as long as two years.

The good news is that you can recover, but you likely need to make some changes in your daily routine, and this may include cutting back on your exercise. Recovering between sessions is always important, but even more so if you have adrenal fatigue.

That said, don't quit exercising altogether. Just be sure to listen to your body and rest when you feel tired. Also make sure you're eating a nutrient-dense diet like the one described in my nutrition plan. Avoid stimulants like coffee and soda, as these can further exhaust your adrenal glands.

It's also imperative to control your blood sugar levels. One of the easiest ways to do this is to eat a diet of real food. By avoiding processed foods, you automatically and drastically reduce your sugar consumption, allowing your blood sugar, insulin and leptin levels to normalize.

As noted by Fish:5

"Dr. Jill Carnahan, a functional medicine doctor ... is quick to point out that any treatment plan should consider all the lifestyle habits contributing to your stress, including exercise. 'Treating the adrenals won't really help unless you also treat the condition's root cause,' says Carnahan. For runners and other active people, she emphasizes not training too hard during the adrenal fatigue recovery period, which may take several months.

'It's important to remain active but avoid overexertion, which further stresses the adrenals and makes recovery difficult.' ... 'I recommend activities that trigger calm-inducing chemical shifts in the brain and body such as meditation, relaxing walks ... playing with the dog, yoga, fishing, or some other hobby or fun activity you enjoy,' says Eads ...

During my recovery, I replaced a portion of my running volume with yoga and meditation. It didn't take long before I was enjoying running again, getting fitter even while running less than before. Changing my diet was also critical ... in particular cutting way back on coffee and ... [energy] drinks ... But I noticed the most significant improvements when I changed my daily diet to include more vegetables and less processed foods."

'Move More, Exercise Less' May Be Key to Adrenal Fatigue Recovery

In recent years, I've placed increasing focus on the importance of staying active throughout the day. Simply standing up more and avoiding sitting as much as possible may actually be a more foundational part of health than having a regular fitness regimen. Ditto for regular walking. I recommend striving for 7,000 to 10,000 steps a day.

This advice may be even more important if you're suffering from adrenal fatigue and have lost your motivation and/or ability to complete your regular workouts. It's important to stay in motion without taxing your system too much, and walking is an excellent option. As your recovery progresses, you will be able to gradually increase the intensity of your walks, and begin to add in other forms of exercise as your energy level returns.

I believe it's virtually impossible to be optimally healthy without exercise, but if you're under a lot of stress, or if you exercise too hard, too often, especially without adequate recovery, you could be taxing your body to the point of breakdown.

Adrenal fatigue is one possibility of pushing too hard for too long. So learn to tune in and listen to your body. And if you start to experience symptoms of adrenal fatigue, take proactive steps to diagnose and address it. There's just no reason to suffer needlessly, as you CAN recover. And, the sooner you catch it, the sooner you'll be back to feeling like your old self again.