In this blog, I'll show you how cardio can damage the thyroid as well as explain the popular knee-jerk response people give when they hear that cardio is not a good idea: '...but it feels good.' I also want to show you how 'feeling good' from exercise can contribute to the slow demise in your health. Oh, and I explain food addiction for ya... At the end, I comment on probably the most difficult and seemingly 'counter-intuitive' part of for most people (including the fitness industry) to grasp...why I, an exercise professional, recommend eliminating or reducing exercise for some people.
In ‘Women: Running into Trouble‘ (contains 80 references), physicist and author Kiefer, explains:
- Studies demonstrate beyond any doubt that in women, cardio chronically shuts down the production of the thyroid hormone, T3.
- T3 is the body’s preeminent regulator of metabolism by throttling the efficiency of cells. T3 acts in various ways to increase heat production.
- When T3 levels are normal, the body burns enough energy to stay warm and muscles function at moderate efficiency. Too much thyroid hormone (hyperthyroidism) and the body becomes inefficient making weight gain almost impossible. Too little T3 (hypothyroidism) and the body accumulates body fat with ease, almost regardless of physical activity level.’
From an evolutionary perspective, Kiefer discusses our adaptive response to running that results in diminishing returns. He also highlights another important factor:
- But wait. By acting now, you too can lose muscle mass. That’s right. No more muscle because too much steady-state cardio triggers the loss of muscle. 42-45 This seems to be a two-fold mechanism, with heightened and sustained cortisol levels triggering muscle loss,46-56 which upregulates myostatin, a potent destroyer of muscle tissue.57 Oh yeah — say good bye to bone density too — it declines with the muscle mass and strength.58-64 And long-term health? Out the window as well. The percentage of muscle mass is an independent indicator of health.65 Lose muscle, lose bone, lose health—all in this nifty little package.
- The “cardio craze” — and it is a form of insanity — is on my hit list and I’m determined to kill it. I don’t know what else I can say. There are better ways to lose fat, be sexy and skinny for life, better ways to prepare for the stage. Women, you need to get off the damn treadmill; I don’t care what you’re preparing for. Stop thinking a bikini-body is at the end of the next marathon or on the other side of that stage. It’s not if you use steady-state cardio to get there — quite the opposite. The show may be over, the finish line might be crossed, but the damage to your metabolism is just starting.
Ray Peat, Ph. D. on Exercise & Thyroid
Don’t *believe* thyroid disorders are real?
An estimated 20 million Americans have some form of thyroid disease. And up to 60% of those with thyroid disease are unaware of their condition.1
In my opinion, hypothyroidism (or hypothyroid type symptoms) is similar to gluten intolerance and eating disorders, they are under-diagnosed and causing/contributing to more health problems than we realize.
…But I Feel Good!
Yes I know, when we exercise and do it right, it does feel good. But it can also be done wrong and feel good. That feeling of sugar & spice does not automatically guarantee a health benefit for you.
In fact, if you are one of the millions of Americans that are chronically stressed or if you have already damaged your metabolism, then that ‘good feeling’ comes with a serious metabolic price tag. That ‘good feeling’ is produced from catecholamines.
Catecholamines are molecules that are released by the adrenal glands in response to stress. They include epinephrine (adrenaline) and norepinephrine (the “fight-or-flight” stimulatory hormones) and dopamine.
What Happens When Catecholamines Are Chronically Elevated?
Similar to a honeymoon. You feel euphoric at first, but that feeling wears off and an ugly side appears…
- Fat loss stops
- A need for more just to feel good
- Appetite becomes unregulated
- Mood disorders
This is what’s known as ‘The Catecholamine Honeymoon’ (coined by Matt Stone of 180 Degree Health). The more stress a body has, the less resilience that body has. The less resilience, the less it can tolerate exercise. And the less it can properly manage catecholamines & other hormones. Here is the best article on this topic explaining clearly what happens with this phenomenon and how exercise (and dieting) can be damaging to metabolism: The Catecholamine Honeymoon
Catecholamines are also involved in addiction. If you have ever worked with ED or addicts, then you’re familiar with this issue. The same phenomenon (to varying degrees) is happening in many cardio-based group fitness classes like Spinning or Physique 57. Notice those ‘serious’ ppl in line 30 min before the class all ‘amped up‘? They’re getting their fix and they are dead serious about it.
Betcha Can’t Eat Just One – Dopamine & Body Fat
Dopamine has many functions in the brain, including important roles in behavior and cognition, voluntary movement, motivation, punishment and reward, inhibition of prolactin production (involved in lactation and sexual gratification), sleep, mood, attention, working memory, and learning.2
For those interested in learning more about how our bodies’ reward system relates to food, eating habits & body fat…wait, let me be more clear:
If you want to know a primary reason why so many people eat garbage, and how corporate food production is largely responsible for our overweight/obesity and children’s health problems by scientifically hoodwinking our evolutionary drives for food & pleasure, then ‘meet the scientists who create flavors that make foods and beverages so tasty that critics say they’re addictive’: The Flavorists: Tweaking Tastes and Creating Cravings.
‘The food reward hypothesis of obesity states that the reward (reinforcing, motivational) and hedonic (pleasure, palatability) value of food influence food intake and body fatness, contributing to the development of obesity. Quite a bit is known about the central nervous system (CNS, i.e. brain) circuitry that underlies reward and hedonic processing, and how this circuitry influences food intake and body fatness. Most of the research on reward and hedonic processing began with the study of drug addiction in animals and humans, however these circuits evolved to guide behaviors that enhance fitness in the natural environment such as those relating to food and sex…
Dopamine: Molecule of Addiction
For visual types, this is a really cool 6 video series explaining how the brain’s reward (dopamine) system works. Although the series is about porn addiction, you can simply replace ‘porn’, with ‘food’, ‘drug’, etc and learn the same thing: the biochemistry of addiction. The monkey studies are funny, but the overall presentation on dopamine, reward & addiction is umm, dope (read: fantastic).
More than 60% of the American population doesn’t do much exercise (and what little they do is questionable) and 25% do nothing. For the relatively small number of people who decide to take responsibility for their health, I hope you see the idea that ‘any exercise is good exercise‘ is not true and there are better choices for exercise than the popular ones.
For the people I meet every single week who have damaged their metabolism and need to do restorative exercise only: I know you want to do something else, I get it. I know you want to, but that doesn’t mean you should. I know you want to feel better from exercise, but you’re not feeling crappy because you are lacking exercise. Rather, you feel crappy because your metabolism is stressed. The more stressed a metabolism is, the less exercise is appropriate. And when exercise is appropriate, cardio is a bad choice.
Want to lose weight? Change your diet. Don’t do cardio.
Stressed & want to feel better? Prioritize. Those catecholamines will cost you.
If you are relatively healthy, do not have a history of eating disorders or yo-yo dieting, are getting sufficient sleep, are already proficient in basic strength training (deadlifting, squats, pushing, pulling) and want to add circuit training to your program, here is a new program I suggest.
This is a comprehensive program that includes over 300 exercise videos, a workout manual to track your progress, interval training programs and it does not require a gym, although you can easily add these routines to your gym workout. If you are familiar with the BURN classes I used to offer, you’ll like this…check out the new Underground Workout Manual…
Click on the Underground Workout Manual Image!