Hypothyroidism and Athletes

by Dr. Jason Barker April 22, 2016

Hypothyroidism and Athletes

The Basics of the Thyroid Gland

Located about where you’d wear a bowtie, the thyroid gland plays a vital role in overall cellular metabolism. Meaning, it sets the rate at which the many thousands of ongoing chemical reactions occur in each cell of the body. It does this by manufacturing specific hormones that are tightly regulated.

There are numerous conditions that affect the thyroid, either causing it to speed up or slow down. In general, when the thyroid runs more slowly than normal, this is referred to as hypothyroidism, while hyperthyroidism refers to a situation in which the thyroid runs much faster than normal.

While it’s beyond the scope of this article to go into each and every thyroid condition, by far the most commonly encountered thyroid issue is hypothyroidism.

Hypothyroidism occurs when too little thyroid hormone is produced. About 10 million people in the U.S. are affected with it, and as many as 10% of women are hypothyroid (and while researchers are unsure why more women have hypothyroidism, women are more affected by autoimmune conditions as one possible cause).

Are Athletes Disproportionally Affected by Hypothyroidism?

A few years ago an article in the Wall Street Journal seemed to imply that elite runners were being treated for hypothyroidism as a performance advantage – the doctor featured in the article claimed he was treating lower-ranging thyroid hormone levels in his elite runner patients. I’ll come back to this in a minute – at the same time the article raised the question of whether elite levels of training actually sets athletes up for hypothyroidism.

As of now, there isn’t a lot of convincing research that says extreme training will induce hypothyroidism. It has been shown to transiently decrease one thyroid hormone known as T3.(1,2) But, as of now there aren’t any studies demonstrating long term thyroid suppression from elite training levels. (T3 is transiently decreased, at least in these studies, because acute stressors will do that).

Now back to the doctor who treats lower-ranging thyroid levels in elite athletes. I have no way of knowing at what level of which thyroid hormone he initiated treatment in his athletes, but I’m willing to bet he took a more conservative approach in analyzing a combination of thyroid hormones (TSH, free T3 and free T4, among others) as many functional medicine practitioners like myself do.

The performance enhancing effects of thyroid medication are dubious – it’s not regulated by the World Anti-Doping Agency, the body responsible for monitoring performance-enhancing drugs. Yet by treating a functionally hypothyroid athlete, we can expect that athlete’s performance to improve only because they’ve achieved normal thyroid hormone levels just as their healthy competitors already have.

Standard Ranges of Thyroid Hormones:

  • TSH: 0.45 – 4.5 µIU/mL
  • FreeT4: 0.82-1.77 ng/dL
  • FreeT3: 2.0-4.4 pg/mL

Taking a functional medical approach to thyroid lab values simply means that we take a finer tooth comb, so to speak, to the established “normal” thyroid hormone ranges. This, combined with a detailed assessment of the patient’s symptoms (and taking into account adrenal function) we often end up addressing thyroid problems that had been missed by conventional methods.

Functional Thyroid Hormone Ranges:

  • TSH: Optimal levels are 1.0-2.0 µIU/mL
  • FreeT4: Optimal levels are 1.45-1.77
  • FreeT3: Optimal levels are 3.4-4.2
  • Reverse T3: 9.2-24.1 ng/dL  (this test is rarely run…)
  • Thyroid antithyroglobulin antibodies (TAA): Less than 20 IU/mL
  • Thyroid perioxidase antibody (TPO): Less than 35 IU/mL

This isn’t to say that only elite athletes need a functional approach to thyroid health; everyone does! Too often people with hypothyroid symptoms are left to suffer because their doctor adhered to the standard lab values, and finding them “normal” despite the patient’s hypothyroid symptoms, did not initiate treatment.

This is actually a huge problem in medicine today as there is definitely a paradigm shift occurring in this area. By taking this approach, many people who actually have some form of hypothyroidism and ‘unexplained’ low thyroid symptoms can be treated, with success.

Typical Hypothyroid Symptoms:

  • Fatigue
  • •Weight gain or inability to lose weight
  • •Hair loss, brittle, or dry hair
  • •Abnormal menses
  • Constipation
  • Muscle aches and cramps
  • •Cold intolerance (can’t tolerate cooler temperatures)
  • Dry skin
  • •Depression or irritability

Labs To Run – How To Get To The Bottom of It!

If you’re concerned about your thyroid status, get it tested! But don’t just get a TSH done – you need to ask (well, probably demand!) for a full thyroid panel (as listed below). And, it never hurts to see if you’ve got an autoimmune-induced hypothyroid condition. You’ll need both antibodies (TPO and TAA) to rule this out.

I’m always amazed at how many fatigued people come into the clinic, have had some bloodwork done yet no one looked at their thyroid status! And, if they did it was only a TSH. That single lab alone won’t tell the whole story. You need to get all of the following labs to get a complete picture of your thyroid function. Next, you need to find a doctor who is familiar with a functional approach to thyroid conditions, in the event you need some help.

A full thyroid panel includes:

  • TSH
  • Free T3
  • Free T4
  • Reverse T3
  • TPO (thyroid peroxidase antibodies)
  • TAA (anti-thyroglobulin antibodies)

In a future blog, we’ll look at the nutrition your thyroid needs to run properly, and explore why people get thyroid problems in the first place, along with some tips for healing and improving thyroid efficiency!


1. Baylor LS, et al. Resting thyroid and leptin hormone changes in women following intense, prolonged exercise training. Eur J Appl Physiol. 2003 Jan;88(4-5):480-4.

2. Boyden TW, et al. Thyroidal changes associated with endurance training in women. Sports Exerc. 1984 Jun;16(3):243-6

Dr. Jason Barker
Dr. Jason Barker

Leave a comment

Comments will be approved before showing up.

Also in Natural Athlete Solutions

How to Have Healthy Bones
How to Have Healthy Bones

by Dr. Jason Barker December 12, 2016

Read More
Nutrition for Bone Health in Athletes
Nutrition for Bone Health in Athletes

by Dr. Jason Barker October 13, 2016

Read More
Stress Fractures and Bone Health in Athletes
Stress Fractures and Bone Health in Athletes

by Dr. Jason Barker September 16, 2016

Read More
Subscribe To OUr Weekly Newsletter