
Can overtraining cause hypothyroidism?
The benefits of exercising have been well known, however there is a fine line between training and overtraining. Have you ever wondered how much exercising is too much or what are the consequences of pushing your body beyond the breaking point?
Many fitness gurus and health experts may often argue that the human body can never have too much exercise, but the reality is that our bodies too have a limit and crossing it can produce gruesome results.
Athletes who have spent all their lives training for the Olympics are the best example of what side effects overtraining can have. It’s not only limited to the constant risk of injuries but rather a new metabolic issue that affects their performance and overall health that may be a concern.
Table of Contents
3 Negative Effects Of Overtraining
There are many causes of hypothyroidism but overtraining leading to hypothyroidism is something that most people would refuse to believe. Most people know that too much training can often lead to injuries, buildup of lactic acid, muscle damage and joint problems.
Recent discoveries suggest that hypothyroidism especially when combined with dieting and mental or emotional stress is one of many possible side effects of overtraining. It could happen not only in athletes but also in those people who push themselves too much, do endless cardio and over-exercise to achieve their weight loss goals.
1. The diagnosis of hypothyroidism in endurance athletes is consistent with research showing that extreme stress is often a trigger of this condition. Training long and hard induces a stress response that raises cortisol and can cause the suppression of the hypothalamic-pituitary axis.
Chronically elevated cortisol levels can result in hypothyroidism, autoimmunity and a host of many other health problems such as fatigue, depression, sleep issues, weight gain as well as lower metabolism and athletic performance. With time adrenal exhaustion and weakened adrenal function set in and this in turn can cause secondary hypothyroidism.
Both high and low cortisol negatively affect your thyroid function.
2. Another common effect of intense and excessive exercise is a neurotransmitter imbalance. As we start pushing our body beyond the limit and train for longer periods of time, dopamine, glutamine and 5-HTP levels become depleted and contribute to chronic fatigue, depression and many hypothyroid symptoms. To avoid these negative effects exercise should be mild.
3. Overtraining can also have harmful effects on the immune system. Some research studies confirmed that overtraining triggers a cellular damage that can result in activation and hyperactivity of the immune system when changes in activity of peripheral blood lymphocytes and natural killer cells occur. This overreaction of the immune system following intense overtraining can trigger an autoimmune disease.
Three-time Olympian Venus Williams received a diagnosis of exercise-induced asthma in 2007, however medication didn’t make her feel better. Venus said that she struggled with fatigue and difficulty breathing for years before she got diagnosed with a Sjogren’s syndrome in 2011. It took her over 4 years to get a proper diagnosis and explanation for her swollen hands, chronic fatigue and misshapen joints that were due to her autoimmune condition.
A proper diagnosis and treatment gives athletes an edge over competitors who unknowingly suffer from an autoimmune disease and/or hypothyroidism. Many undiagnosed athletes and people who exercise but are unaware of their underlying condition think if they work harder they can train through it and the persistent fatigue and weakness will go away. In fact, further pushing can make things even worse.

Venus Williams speaks about her autoimmune disease
Venus Williams. Image Source: Justin Hoch
Olympic Medal Winners With Hypothyroidism
Athletes who train for the Olympics are vulnerable to developing an autoimmune disease and hypothyroidism due to high intensity training and tendency to overtrain. Some of the biggest names who have been diagnosed with hypothyroidism are Gail Devers and Carl Lewis.
Carl Lewis is perhaps one of the most celebrated Olympian’s ever, winning 9 gold and 1 silver medals throughout his career. Lewis was diagnosed with hypothyroidism on a routine checkup, just months before his 5th and final Olympics and further testing revealed autoimmune Hashimoto’s disease.
Like most people Lewis was unaware about signs and symptoms of hypothyroidism before his diagnosis. Only after his diagnosis he realized that he gained weight due to low thyroid function. Lewis had always been someone who spent a lot of time training and experts believe that it was his constant overtraining which led to hypothyroidism.
Despite his condition, Lewis won his 9th Gold medal in the 1996 Olympics just five months after he was diagnosed. You can read more about Carl Lewis’ Olympic preparation and his experience with hypothyroidism in his book One More Victory Lap: My Personal Diary of an Olympic Year.
Five-time Olympic gold medalist Gail Devers was only a couple of years into her running career where, in spite of defeating every opponent, she came crashing down with abnormal weight loss, hair loss, fatigue and brittle nails.
Watch a video interview with Gail Davers where she talks about her experience with getting diagnosed and describes her symptoms as “traumatic”.
Fearing that her career as an athlete had come to an end even before it got a chance to take off at the age of 22, she went from doctor to doctor, but no one was able to offer a credible diagnosis to her health problem. Her condition remained undiagnosed for years and doctors dismissed many of her symptoms such as weight loss, fatigue and rapid heart rate as normal for a high performance athlete.
After battling her condition for almost 2 years, doctors were finally able to figure out that she was suffering from Graves disease and hyperthyroidism. She received a radioactive iodine treatment for hyperthyroidism and was put on a thyroid hormone replacement therapy for hypothyroidism. After almost a year of treatment, she was ready to get back on the track and went on to win her first Olympic Gold medal.
How Much Training Is Too Much?
This is different from person to person and it is important to listen to your body.
Symptoms of overtraining could include:
- Fatigue
- Unusual tiredness that persists over long periods of time
- Reduced physical performance
- Inflammation
- More frequent injuries and colds
- Slow post-workout recovery
- Sleep issues
- Inability to build muscles
- Anemia
- Loss of motivation
- Depression
- Cramps
- Decreased stamina and strength
- Weight gain
- Aching joints and muscles
If you already have hypothyroidism and/or autoimmune disease your symptoms can worsen. In this situation more thyroid medication is not an answer and in some cases especially when adrenals are involved it even can do more harm than good.
The key is to avoid overtraining and find the right balance by choosing a type of exercise that makes you feel right and you enjoy.
How To Choose The Right Type Of Exercise
Exercise shouldn’t drain you out of energy, they should boost your energy. Some muscle soreness after the training is normal, however you should feel more energized after the workout than before you started. You should have a good mental focus and mood during the recovery periods. If you don’t feel this way than you are doing the wrong type of exercise for you.
Some people with thyroid problems may find exercising difficult. If you are one of them watch the video below where a holistic practitioner explains what type of exercise is safe and effective if you have hypothyroidism.
P.S. Do you like what you read and want to get more? Subscribe to our Thyroid News and get FREE eCourse Hypothyroidism Diet Guide