I recently finished reading Mark Sisson’s Primal Health book, which by the way is a real gem! The book highlights the term “Chronic Cardio.” I remember hearing about this condition in the late 90’s while doing research for my Master’s in Kinesiology and sadly still see it happening today.
What is Chronic Cardio, well in a nutshell, over-training. A physical state where too little rest and recover is built into the exercise training program. All performers, athletes and us regular folk too, are constantly looking for ways to improve performance levels. This drive needs attention to both far ends of the spectrum, too much and too little.
The National Institutes of Health (NIH) calls it Overtraining Syndrome (OTS). A review in Sports Medicine lists a host of potential OTS symptoms.
- Elevated morning resting heart rate
- Frequent colds and infections
- Struggling with training
- Persistent fatigue
- Loss of appetite
- Muscle soreness
- Lack of focus
- Sleep issues
Sisson expounds on the serious heart issues with endurance athletes here. Needless to say this is something to take seriously. While getting in the groove and maintaining a strong exercise program is commendable, 5 to 6 days a week doing “cardio-workouts” may not be positively supporting vibrant health and longevity.
Why and what is happening?
This is a VERY BROAD STROKES overview but let’s look at a couple contributors to Chronic Cardio or OTS, raised cortisol and lack of sleep.
“Unfortunately, when the stress response is triggered repeatedly (by the constant hectic pace of modern life, by a demanding boss, or by overly stressful workouts), your stress response mechanisms eventually wear out, and you produce lower-than-normal levels of cortisol and other hormones critical to many aspects of everyday health. Thyroid hormones and testosterone also become dysregulated from prolonged stress, resulting in fatigue, loss of lean muscle tissue, a suppressed immune system, and the general conditioning best described as burnout.“
Mark Sisson, The Primal Blueprint, 4th Edition, Primal Blueprint Publishing. p.48
Chronically Raised Cortisol
Any type of exercise particularly in the medium to high intensity range is putting stress on the body. Some of that stress is a good thing, like building your bones and muscles. However, if cortisol is raised due to high stress consistently and chronically certain hormonal functions may be hampered.
For example, research shows that with elevated cortisol the body is in “store fat mode”, a natural display of the fight or flight human reserve mechanism. Elevated cortisol means insulin is elevated thus preventing utilization of your own body’s fat stores. The irony here is many individuals still hold fast to the idea of exercising to lose weight, and why they are going multiple times to the gym to try to lose a few pounds. See post on exercise to exercise not to lose weight and a brief video by Gary Taubes on exercise may not help you lose weight.
Dr. Eric Berg has a couple very articulate videos on signs of raised cortisol, here as well as another video on why it is hard to turn stress off, but doable, link here. As you know with everything health and wellness concerned it is the whole package of efforts not just one singularly.
That said, keeping your cortisol and thus insulin low by not eating foods, such as carbohydrates and sugars along with participating in exercise in healthy amounts rank in the positive column. Chronic cardio exercise can be a negative contributor to higher levels of cortisol adding to your stress level and making it very hard to lose weight and or maintain good metabolic health.
Lack of Sleep
In a 2018 review of Circadian Rhythm, Obesity and Microbiome researchers found the following:
“Insufficient sleep leads not only to an increase of the total calorie intake but changes the meal preference in favor of palatable foods and meals with high carbohydrate content. A decrease of leptin and increase of ghrelin levels caused by sleep deficiency can also play a role.”
For those not familiar with leptin and ghrelin they are the hormones respectively guiding hunger and satiety. Ghrelin stimulates appetite and promotes fat storage, while leptin does the opposite, inhibit hunger, and regulate energy balance. In other words, lack of sleep which is a common by-product of overtraining can be a contributor to your body’s inability to control appetite as well as dysfunction of fat burning and fat storage.
The point of bringing this up is to take a broad view and assess your current exercise regime so that you are maximizing the benefits on all ends. It is NOT that you shouldn’t exercise vigorously but that you must incorporate rest and recovery, keep insulin levels low, monitor cortisol specifically chronically high, and develop regular sleep patterns. These are crucial elements of a well-formulated exercise program.
“No bird soars too high if he soars with his own wings.”
William Blake
