You have a slow thyroid. Your TSH is high, and your T3 is low. And you have a lot of the symptoms that go along with a slow thyroid:
- Weight gain
- Fatigue
- Constipation
- Weakness
- Brain fog
- Depression
…and others.
You don’t like how it feels, so you’ve tried the common things:
- Medications (Synthroid/Eltroxin AKA levothyroxine)
- Supplements
- Diet
But I’ll bet that you haven’t tried exercise as a way of improving thyroid function. Too bad, because it can both directly improve the levels of thyroid hormones (the ones usually measured are TSH and T3), as well manage the symptoms of hypothyroidism.
The problem is that even when people with hypothyroidism exercise, they’re not doing it right. Or at least, not in the most direct way that improves thyroid levels. As you know from my articles in the “chronic conditions” series, what’s good for high blood pressure is different than what’s good for diabetes, which is different than what’s good for osteoporosis, which is further different than what’s good for anxiety and depression.
There needs to be specificity in exercise prescription. And that’s what you’ll get in this article. Unfortunately, there’s not a single great article on the internet that talks about how to exercise if you have a slow thyroid. Sure, there’s some “fluffy” advice, like general “exercise is good for you” and “you should go for a walk”, but it leaves a lot to be desired, like:
- How does hypothyroidism affect exercise?
- How does exercise affect thyroid levels?
- Can walking reduce thyroid stimulating hormone (TSH) levels?
- What is the best exercise for hypothyroidism?
- Exercise for thyroid patients to lose weight
This will be that guide that needs to exist, but doesn’t – the most comprehensive guide on the internet about how to exercise with a slow thyroid.
But if you want something personalized designed to help you with your own thyroid, we have a special program for that, called “Thyroid Power.” If you want to figure out whether you qualify for this program, just email me with the words “Thyroid Power” in the subject line.
And now, without further ado, let’s get to it!
How Does Hypothyroidism Affect Exercise?
Firstly, we know that people with a slow thyroid complain of more fatigue, and there’s something called “exercise intolerance.” That is, someone with a slow thyroid is able to tolerate less exercise than someone with a normally functioning thyroid.
Why?
Because the thyroid hormone is like the “gas pedal” on your metabolism. If that gas pedal isn’t pushed hard enough, everything in the body happens slower. From the delivery of oxygen to working muscles, to the speed of muscle growth and strength, and more.
So those are the different mechanisms by which hypothyroidism reduces exercise capacity.
But how big is the difference between people with a slow thyroid, and those without? As far as endurance is concerned, it’s huge! In one study, the aerobic capacity (VO2max) was measured both in people with a slow thyroid, and with a normal thyroid, and they found that in people with a normal thyroid, their aerobic capacity was 45.76 ml/kg/min. In those with a slow thyroid, their aerobic capacity was only 36.19 ml/kg/min. If those numbers don’t mean anything to you, suffice it to say that on average, people with a slow thyroid have 21% less endurance than people with a normal thyroid.
Interestingly enough though, it seems like muscle mass isn’t affected by having a slow thyroid. In one study, when people with a slow thyroid were given thyroid medication, to bring their thyroid levels to normal, their muscle mass didn’t change. Furthermore, it didn’t really differ much from people whose thyroid was fine their whole life. That’s not to say that they shouldn’t strength train, or they won’t benefit from strength training, but it does seem like having hypothyroidism really affects the cardiorespiratory system more than the muscular system.
How Does Exercise Affect Thyroid Levels?
If you have hypothyroidism, you know that when your thyroid is low, your TSH test is high.
We know that exercise itself is good (if you do it properly), but what we really want to know is does it just manage the symptoms of hypothyroidism, or does it directly affect thyroid hormone levels? Fortunately, the answer is both.
In one study, researchers recruited 20 people, all of whom had a slow thyroid, and divided them into 2 groups:
- Group 1 did cardio for 1 hour per day, for 3 months
- Group 2 didn’t exercise
After 3 months, the results were pretty impressive:
- Group 1 lowered their TSH from 2.51 to 0.61
- Group 1 increased their T3 levels from 1.30 to 2.33
Another study done in postmenopausal women found the same thing:
- After 8 weeks of cardio, 3 times per week, 45-60 minutes per workout, at an intensity of 65-75% of the maximal heart rate, TSH dropped from 2.71 to 1.91, and T3 rose from 1.44, up to 1.9.
Knowing this, one question that often comes up is “can walking reduce thyroid stimulating hormone (TSH) levels?”
As you can see from the research above, the answer is “yes” with a big IF. That’s “yes” IF you do it at the right intensity (as you’ll learn soon, that’s about 70% of your maximal heart rate), the right frequency (3-6 days per week), and the right duration (30-60 minutes).
What Is the Best Exercise for Hypothyroidism?
When it comes to exercise prescription, we want specificity. You can spend 60 minutes exercising, but if it’s the wrong exercise, it won’t do you much good, and may even do some harm. We also want to use our time as effectively as possible.
So we need precision in exercise prescription. What are the parameters of exercise prescription? They are:
- Frequency: how many times per week
- Intensity: how hard
- Time: how long
- Type: cardio, strength training or stretching
As far as frequency, time, and type goes, all the studies looked at previously used a:
- Frequency of 3-6 times per week
- Time: 30-60 minutes
- Type: cardio
The missing element is intensity, and that’s what one study decided to look at. The researchers recruited 60 people, and made them exercise at different intensities for 3 minutes.
- The first 3 minutes were done at an intensity of 45% of the maximal heart rate (that’s very gentle exercise, like a light stroll)
- The second 3 minutes were done at an intensity of 70% of the maximal heart rate (that’s moderate exercise)
- The last 3 minutes were done at an intensity of 90% of the maximal heart rate (that’s intense exercise)
In between each 3-minute segment, the exercise was stopped just long enough to take blood, and look at thyroid hormone levels.
What researchers found was:
- The higher the intensity, the higher the TSH
- Free T3 (the hormone that really influences how the thyroid is working) had the highest level at 70% intensity (6.46 pmol/l). It was the lowest at 45% intensity (5.30 pmol/l), and higher at 90% intensity (6.17 pmol/l)
What that tells us is that the thyroid responds best to moderate intensity exercise.
So as it stands right now (this may change in the future, as more research is done), the exercise prescription for hypothyroidism is:
- Frequency: 3-6 times per week
- Intensity: 70% of your maximal heart rate (subtract your age from 220, and multiply that number by 0.7. That’s how many beats per minute you should be exercising at)
- Time: 30-60 minutes
- Type: steady state cardio
Exercise for Thyroid Patients to Lose Weight
People with a slow thyroid frequently wonder how to lose weight. And I get it – it’s very frustrating when the amount of food that you used to eat to maintain your weight now makes you gain weight.
The reason for that is that a slow thyroid slows down the metabolism by around 200-300 calories per day. If one pound of fat contains 3500 calories, that’s a rate of fat gain of around 1 pound every 2-3 weeks, until it stabilizes.
The tendency may be to exercise more to make up for the slower metabolism, but I would advise against it. When you burn more calories from exercise, you burn fewer calories from other sources. For instance, if you exercise so much, so long or so hard that it takes a lot out of you, all the small movements you do throughout the day (like fidgeting, that you don’t even notice) start to decrease.
So I would exercise just the right amount, without going overboard. I write much more extensively on the right exercise for weight loss in this article.
Unanswered Questions
Unfortunately, there isn’t as much research into how to exercise with a slow thyroid as I’d like. Much of the research on the changes in thyroid hormone with exercise is done on healthy people – not those with a slow thyroid. We can only generalize from the population studied, but we don’t know if people with a slow thyroid would have the same responses.
As it stands right now, here are some questions where there aren’t any answers:
- How does strength training affect thyroid levels?
- How does having a slow thyroid affect muscle strength? We know that muscle mass is unchanged, but what about muscle strength?
- We know that the amount of muscle mass and strength is no different, but what about the speed of gain of muscle and strength? Is that the same as in people with a normal thyroid, or slower?
- Is there any difference on thyroid hormone levels when you do steady state cardio vs. interval training?
- What’s the least amount of exercise you can do, and still see changes in thyroid levels?
- What’s the optimal amount of exercise you can do, to see the best changes in thyroid levels?
- Is there a point of diminishing returns, or negative returns? In other words, is there a point where you exercise so hard and/or so long that the thyroid paradoxically slows down even more?
As more research becomes available, I’ll update this article.
In the meantime, if you want something personalized designed to help you with your own thyroid, we have a special program for that, called “Thyroid Power.” If you want to figure out whether you qualify for this program, just email me with the words “Thyroid Power” in the subject line.
