*Warning for possible triggers regarding eating disorders.*
Your body grows and repairs when you rest – even babies know that! And also: Babeez spooooning!! Awwwwww.
“How did you find time to exercise 3-6 hours a day?” (I organized everything else in my life around exercise, didn’t sleep much and did insane stuff like shuttle sprints in the dark parking lot after doing my grocery shopping. Also, I didn’t watch TV.)
“How skinny did you get?” (Not as skinny as you’d think I would have been.)
“I want an exercise addiction, hahah!” (Come over here so I can smack you.)
“No seriously, that’s really a problem?” (Yes. It’s a type of eating disorder.)
Over the years as I’ve spoken more openly about my years of compulsive over exercise, people understandably have lots of questions. But one question I’ve gotten a lot lately is “How did you know you needed help?” The sad-but-true answer is I didn’t. I was so deep into my illness that I couldn’t see it for what it was. But I can tell you what finally drove me to seek medical care.
It wasn’t the runs in the dark in the middle of winter at 4 a.m and again at 10 p.m. It wasn’t leaving my son’s hospital bed to go do a high-intensity interval class instead of showering for the first time in three days or sleep. It wasn’t when I fainted after running a marathon followed by an hour of kickboxing – can’t miss a workout! – without drinking or eating anything and then being carried down the gym stairs by a friend who tried to make me drink a Vitamin Water which I refused because it had 50 calories. It wasn’t even when my heart started doing this weird sick jumping in my chest and I briefly wondered if I was going to die on the floor in front of my young children.
No, the thing that made me finally talk to a doctor was when I gained ten pounds in one month because all my over-training (fancy code word for compulsive over-exercise) had suppressed my thyroid. Those 10 pounds completely unhinged me. That is how deeply ill I was.
A lot of people are surprised by the connection between over-training (even if it’s not an addiction or disorder) and an under-functioning thyroid. I know I was sure surprised when my doctor told me the results of my blood tests. I’d never had thyroid issues before! As she gently went through my daily schedule with me she observed dryly, “You’ve beat your thyroid to death. Literally, with all that kick boxing.”
I gulped. “So what do I do?”
“All of it.” I almost fainted.
And with that pronouncement I was on doctor-ordered rest from all exercise – even walking on the treadmill! – for 8 long weeks after which point we’d retest my thyroid.
I was reminded of this moment when I read this little story on Athlete.io (thanks Stephanie for the tip!):
“I watch my friend Jessica running on the treadmill—day after day, year after year—like a madwoman, and going nowhere. Her body seems to get softer with every mile, and the softer she gets, the more she runs.
She’s still fat. Actually, she’s gotten fatter.
I’ve tried to rescue her from the clutches of cardio in the past, but my efforts didn’t work until a month ago, when she called to tell me that a blood test had confirmed her doctor’s suspicion: She had hypothyroidism, meaning her body no longer made enough thyroid hormone.
Her metabolism had slowed to a snail’s pace, and the fat was accumulating. This was her body rebelling. When Jessica asked for my advice, I told her to do two things: To schedule a second test for two weeks later, and to stop all the g*****ed running until then.
She took my suggestion and cut out the cardio. Two weeks later, her T3 count was normal. Go figure.”
Because, it turned out, my story ended the same way as Jessica’s: without any other medical or drug intervention other than not exercising, after the 8 weeks my thyroid levels had returned to normal and I stopped gaining weight.
Your thyroid is basically the corrupt dictator of your body: it controls everything, is very picky, and if you defy it, it will burn your house down. The pituitary gland releases TSH (thyroid stimulating hormone) which tells the thyroid to release T3 and T4. Often when labs “check your thyroid” they are only measuring your TSH levels. Too high means your thyroid is not producing enough hormones, also known as hypothyroidism (inferred because all the TSH means that the normal dose isn’t releasing enough T3 and T4 so the body keeps cranking up production). Too low means your thyroid is over producing, known as hyperthyroidism – which has its own set of issues. What numbers are “too high” and “too low” is actually something of a debate these days and can also depend on which type of test they do so it’s really important to read your test results carefully. The lab notes should say what the “normal” range is and even if you fall in it, if you’re close to either end you may still have symptoms. In addition, you can ask for a “full-panel” thyroid test which can include free T3, free T4 , reverse T3, and cortisol markers because TSH sometimes doesn’t give the whole picture. (At least that’s the way I understand it. This is whole thing is more complicated than calculus so if I screwed up something in this explanation please correct me!! Except for the dictator analogy ’cause I dig it.)
It’s been known for a long time that stress can influence thyroid performance but it’s only been recently that scientists have really looked into how the particular stress of exercise can mess with your ‘roid. A 2012 study recruited a bunch of healthy males volunteers and put them in three groups: a) a group that did 45 minutes of steady state exercise at about 60% of their VO2 max (non-geek speak: they were doing a normal “comfortably hard” tempo run on the treadmill), b) a group that did 45 minutes of high-intensity intervals at 100-110% of their VO2 max (non-geek speak: Gaaaahhhhh most painful workout ever! Seriously 45 minutes of that level of HIIT? I’m kinda shocked none of the participants puked or fainted), and c) the control group of dudes who did nothing.
The researchers then measured the “full panel” of thyroid markers. Their findings were pretty interesting. Both exercising groups saw a spike in thyroid hormones post exercise BUT 12 hours later their hormones dropped way below their baseline levels and stayed abnormally low for 24-48 hours afterward. The effect was worse for the HIIT group. (Charlotte’s note: I’m no scientist but I would guess that’s because the sadists made the poor suckers do super high-intensity HIIT for 45 ever-loving minutes. Other studies have shown that short – like 4 to 15 minute – HIIT workouts are optimal. This type of training is extremely stressful on your body so to maximize the metabolic benefits, you gotta keep it short!)
Another interesting note in the study said that observational analysis of larger groups like military training camps showed that when people exercising also have reduced caloric intake, high emotional stress, and/or a lack of adequate sleep, (sound like anyone you know?) the effect on the thyroid is abysmally worse.
A separate study agreed, “[the data] makes a compelling case that too much cardio can impair the production of the thyroid hormone T3, its effectiveness and metabolism, particularly when accompanied by caloric restriction, an all too common practice. Women inadvertently put themselves into a hypothyroid condition when they perform too much steady-state cardio.” [Charlotte's note: Thanks to all our baby-making machinery, women seem to be more susceptible to this phenomenon than men. The scientists speculated that when we expend large amounts of energy exercising our bodies assume that we're in trouble and start downregulating our whole system to preserve our ability to support a fetus.]
AthleteIO explains it this way:
No matter which way we hope the body works, its endgame is always survival. If you waste energy running, your body will react by slowing your metabolism to conserve energy. Decreasing energy output is biologically savvy for your body. Your body wants to survive longer while you do what it views as a stressful, useless activity. Decreasing T3 production increases efficiency and adjusts your metabolism to preserve energy immediately.
Nothing exemplifies this increasing efficiency better than the way the body starts burning fuel. Training consistently at 65 percent or more of your max heart rate adapts your body to save as much body fat as possible. After regular training, fat cells stop releasing fat the way they once did during moderate-intensity activities. Energy from body fat stores also decreases by 30 percent. To this end, your body sets into motion a series of reactions that make it difficult for muscle to burn fat at all. Instead of burning body fat, your body takes extraordinary measures to retain it. [Emphasis mine]
Short version: If you workout too much – particularly by doing long stretches of medium or high intensity cardio (i.e. running, jogging, or biking NOT walking) – it stresses out your body which raises your cortisol levels. The stress suppresses the function of your thyroid. This signals your body to retain and store fat along with making you extra tired so you won’t be as inclined to burn as many calories. And that? Equals 10 pounds gained in one month from exercising too much.
How do you know if this is happening to you? The most common symptoms of a failing thyroid include fatigue, increased sensitivity to cold, constipation, dry skin, unexplained weight gain, muscle weakness, thinning hair, slowed heart rate, depression and impaired memory. I can tell you that I had every one of these symptoms but you may have just some or others not listed.
How much exercise is too much? While you can suppress your thyroid with weight lifting it’s far more common to do it with excessive cardio. At the height of my disorder I was doing 3-6 hours of intentional exercise (like classes, running, biking) a day. BUT the effects are cumulative over time and so even when I tried cutting back to “just” 2 hours a day, my problems continued to get worse. The other issue is how often you are working out – I was doing 6-7 days a week with no rest days ever. That’s dumb. Your thyroid levels take a minimum of 24 hours and can take up to 6 days (!) to fully recover, depending on how hard you worked.
How long do you need to rest? I get this question a LOT. Honestly this depends on your personal physiology, how long you’ve been over-exercising, the intensity of the exercise and other mitigating factors like stress, sleep, diet and pregnancy. For me 8 weeks was what it took. I read the story of an Olympic swimmer who needed 6 months. You may only need a week. Unless you measure your thyroid levels before and after (like I did) then you won’t know for sure but a good rule of thumb is to rest until you feel the symptoms are totally gone. Also, I had to work back into exercise slowly and from that day forward (up to and including now!) I’ve been under doctor’s orders to not workout more than 1 hour per day.
Do you need medication? Thankfully I hadn’t permanently damaged my thyroid so it came back up to normal function on its own. Others may need medication to help. Only your doctor can tell you what you need to do.
Anything else I can do to make it heal faster? My doctor instructed me to increase my consumption of iodine-fortified table salt (wheeee!) and if I ate cruciferous veggies like cabbage, broccoli and cauliflower to make sure they were cooked.
Moral of the science story: One of the scientists, when asked what people should take away from this research, answered simply, “The benefit from exercise, and there is a benefit, is from the adaptation, not the activity itself.” In other words, your muscles only grow when you rest!
Moral of the Charlotte story: Not exercising will make you sick and gain weight. Exercising too much will make you sick and gain weight. Don’t be me. Find that sweet spot where you exercise to live not live to exercise!
Did I miss any questions about hypothyroidism from overtraining? Ask away and I’ll add the Q&A up here in the main post. Have any of you ever struggled with your thyroid? Any advice to add??
*Note: I am not a doctor and none of this is intended as medical advice. Just use this as a jumping off point to talk to your doctor about your concerns!