Running: Overtraining & Hormones

Let's dig a little deeper into the effects of overtraining.

Testosterone levels will decline. A team of researchers grouped 286 subjects into moderate or heavy exercise groups. They ran for 2 hours, 5 days per week for about 1 year. After that, they spent 9 months with a low intensity running schedule. They found that the pituitary hormones LH and FSH (luteinizing hormone, follicle stimulating hormone) decreased, testosterone levels decreased, and sex hormone binding globulin levels increased. Levels improved back to normal during the low intensity recovery period. They concluded,

"Long-term strenuous treadmill exercises (overtraining syndrome) have a deleterious effect on reproduction." Journal of Endocrinology 2009 Mar;200(3):259-71. Epub 2008 Dec 9

Females can also experience reproductive dysfunction. While the mechanisms are still to be determined, the probable suspect is decreased estrogen production as a result of overtraining. This does more than set women up for poor athletic performance. It sets you up for osteoporosis, infertility, decreased muscle mass & behavioral problems. Journal of Endocrinological Investigation 2001 Nov;24(10):823-32.

The hormone cost of overtraining is considerable. The consequences of these shifts are significant.

Running: Overtraining

Overtraining may involve more than just a drop in your athletic performance. Common symptoms include: headaches, insomina, pain, loss of enthusiasm for running, increased number of injuries, slower healing time, slower recovery time, frequent infections, loss of appetite and more.

Classically, the treatment for overtraining syndrome is rest. Depending on the extent of compromise to your body, this may require complete rest or a substantial reduction in your training time. Let me explain a little of the hormone physiology behind the syndrome.

1. Cortisol production is a priority in your body.
Just as we can say your heart is more important than your feet and your brain is more important than your spleen, we can say that cortisol is simply "a little more important" than many other hormones.

2. Cortisol, testosterone and estrogen have a common mother.
The precursor to all these hormones is pregnenolone. Generally, there's enough pregnenolone to go around so we make adequate amounts of all hormones, but when physical (or emotional) demands are extraordinarily revved up, cortisol production takes priority.

Do you remember the old Star Trek episodes where the Captain would say, "more power to the shields!" during times of attack? Presumably, sending the available power to shields took priority over the lights in the kitchen, powering the microwave oven or whatever else required power. The limited amount of available resource needed to be carefully distributed to get through the day.

Similarly, our pregnenolone needs to be transformed into what matters most at the time.

3. Over time, you won't even make enough cortisol.... or testosterone... or estrogen... to get through the day.
In Star Trek; eventually, the shields went down.
In California; eventually, you'll run out of water.
In overtraining; eventually, you'll run out of cortisol.

When your cortisol production "dries up", other hormone production will also suffer.
_________________________________________

Let me ask women a question? What happens when estrogen levels decline?
The answer is; the classic symptoms of menopause. Muscle mass declines, bone density decreases, fatigue, discomfort, insomnia etc. Sounds familiar?

Now to the men. What happens when testosterone levels decline?
The answer is: muscle mass declines, bone density decreases, fatigue, discomfort, insomnia etc.

Now a question to all runners. What happens when you are overtrained?
The answer is: muscles don't recover as well, bone loss, fatigue, discomfort, insomnia etc.

Running: Protect Your Adrenal Function

As the last entry discussed, the adrenal glands are subject to stress during training. This is perfectly acceptable if you have healthy adrenal status. But if you have some level of adrenal fatigue, you must be prepared to train wisely. If the idea of "adrenal fatigue" sounds a little strange to you, we should describe it more accurately as "hypothalamic-pituitary-adrenal axis dysfunction." This is the biological system that regulates adrenal activity and is commonly referred to as the HPA axis.

HPA dysfunction is common and is related to multiple symptoms.

1. Chronic fatigue. Psychosomatics 2008 Sep-Oct;49(5):450.
2. Irritable Bowel Syndrome. Neurogastroenterology & Motility 2009 Feb;21(2):149-59. Epub 2008 Aug 5.
3. Altered immune function. Journal of Neuroimmunology 2002 Dec;133(1-2):1-19.
4. Depression Psychological Medicine 2009 Apr 1:1-4.

If you already have some level of HPA dysfunction, then aggressive training may actually harm your health. This doesn't mean that you shouldn't run at all. Interestingly, low intensity exercise reduces burden on the adrenal glands. Journal of Endocrinological Investigations 2008 Jul;31(7):587-91.

Because HPA dysfunction is not a "disease" per se, there are no accurate numbers for how many Americans are affected but adrenal health is relatively simple to assess. It involves a simple saliva test that many functional laboratories (i.g. Diagnos-techs, Metametrix, Genova Diagnostics) perform.

If you have experienced a drop in performance, slower race times, slower recovery, gastrointestinal discomfort or fatigue, you may be overtrained. More on overtraining next time.