by Cyrus Peikari, M.D.
I did cardio for over 30 years, but it only made me fatter. I now realize that long, mindless cardio is like accumulating credit card debt on your “adrenal glands”: eventually, your body repays it with metabolic interest.
Cardio isn’t evil. Some people thrive on it. In fact, used sparingly it can relieve mental stress. However, any form of excessive exercise (even resistance exercise) can work against you.
The adrenal glands are small, pyramid-shaped organs that sit on top of your kidneys. They produce multiple hormones that keep you alive and healthy, including sex hormones and stress hormones. One of the stress hormones that your adrenal glands produces is “cortisol”, a cousin to the drug that doctors give you, for example, during a poison ivy reaction (such as Prednisone tablets, or cortisone shots).
I’ll bash cortisol in a minute, but first let me praise it. Cortisol is necessary for survival. In fact, if your adrenals stopped producing cortisol, you would die. I’ve seen this in patients who have autoimmune disorders that shut down their adrenal glands: if they don’t take cortisone pills every day, they sicken and die.
President John F. Kennedy suffered from an autoimmune syndrome known as Addison ’s disease, which attacks the adrenal glands. Addison’s disease is extreme “adrenal insufficiency,” and it’s rare. However, there is a common form of adrenal insufficiency known as “adrenal fatigue.” The main symptoms of adrenal fatigue are chronic fatigue, muscle weakness, loss of appetite, muscle loss, and abdominal pain. (Athletes can suffer a flavor of this known as exercise burnout, or “overtraining”).
Other symptoms of adrenal fatigue are nausea, vomiting, diarrhea, irritability and depression, craving salty foods, low blood sugar, headache, sweating, low libido, and in women irregular or absent menstrual periods.
Patients with adrenal fatigue are among the most complex medical challenges, and for this reason many physicians refuse to see them. (Usually it’s not the doctor’s fault: medical managers routinely yell at employed physicians who spend more than five minutes per patient…one of the main reasons I fled “factory” medicine and started a private practice).
Adrenal fatigue from exercise often happens like this: You want to lose weight, so you get on the cardio machines at the gym. Great news! You’ve lost some weight, but you hit a plateau. The answer? More cardio! OK, great, you’ve lost a few more pounds, but after a few months you hit another plateau. Guess what? You decide to increase the cardio further. Your good intentions are paving the road to metabolic Hell.
This excessive cardio is stressful to the body. In fact, any kind of excessive exercise causes stress. That includes overindulging in resistance exercise such as yoga or weight lifting. I’m picking on cardio simply because it’s the most abused. In the short run, it may seem great, but months (or years) later you’ll pay the price for overdoing it.
The result of all this stress: your adrenal glands respond by increasing cortisol output. To dramatize the negative effects of cortisol, let’s examine the “opposite” of Addison’s disease: a situation where the adrenals produce excess cortisol, known as “Cushing’s syndrome”
Symptoms of Cushing’s syndrome include high blood pressure, abdominal fat (with thin arms and legs), a round “chipmunk” face, a fatty neck, weak muscles, weak bones, acne, and thin skin. Women may have excess body hair and have irregular menstruation. Other symptoms include mood changes, headache, and chronic tiredness. Cushing’s syndrome results from too much cortisol-like medication (such as prednisone), or by a tumor that results in excessive cortisol (known as Cushing’s disease).
When you overindulge in cardio long term, the stress casts a mild shadow of Cushing’s syndrome. You retain belly fat, and you struggle to build muscle.
Another notorious effect of cortisol: your appetite may increase, particularly for junk food.
What happens if you get injured or stop exercising due to burnout? Unfortunately, you’re in a worse situation. Because of elevated cortisol levels, the weight gain returns with a vengeance: it’s far worse than before you started cardio.
As bleak as that sounds, it gets worse. Now that you are frustrated over lack of progress, you might commit the ultimate sin: you cut your calories. It’s a sin I’ve committed many times.
Why is cutting calories so sinister? On the one hand, lowering calories stresses the body, which causes your adrenals to produce more cortisol: the same cortisol that, in long term excess, burns muscle and creates belly fat. Isn’t that the exact opposite of what you’re trying to achieve?
Cutting calories is a big mistake for another reason: it puts your metabolism into “starvation” mode. Your body slows down. Your “basal metabolic rate” decreases. It seems like you are gaining weight again, though you have stopped eating. Welcome to Hell!
Now that we’ve reviewed the science, how do we escape this mess? We said that long, mindless cardio is like accumulating credit card debt that your body has to pay back with metabolic interest. (By the time I see someone in my office, they are deep into years of “metabolic debt.”)
You can start to “pay down” those metabolic credit cards with a number of positive steps. Look to reduce stressors in your life. Most of the time, one of your biggest stressors will be a family member or close friend: a co-dependent relationship. They are stressing you out, which makes you feed back into their stress, creating an endless loop of dysfunction. Instead of a person, it may be an activity (such as needless work stress). A professional counselor helps.
Another way to pay off your metabolic credit cards is by eating more. That’s correct: you may need to eat more. Strategically raising your calorie intake may break through a fat loss plateau.
A third and powerful adjustment to your metabolic portfolio is to re-evaluate your exercise regimen. I usually slash a patient’s workout volume by 50—75%. With less exercise, stress goes down, you’re less hungry, and you burn fat more efficiently. It’s not the quantity, but the quality. Pick the right exercises for your body. That’s why I take my patients to the gym and give them a custom regimen.
Some of you might think, “I don’t exercise at all. How can you cut that down for me?” The answer is that you have exercised in the past, but you got frustrated seeing little or no progress. Since the definition of insanity is to keep doing something that doesn’t work, you did the “sane” thing, and gave up on exercise altogether.
For most, the problem is too much cardio. The solution? Find a good trainer or mentor to coach you on short, low-volume routines.
Just remember to pick someone who doesn’t stress you out.