Zebras and Stress
Courtesy of Wikipedia
I’m finishing up a book on stress I got for Christmas called Why Zebras Don’t Get Ulcers. It is by far one of the best books on fitness and health I’ve read in a while, though there is certainly a lot to digest.
Essentially, he poses the question as to why zebras, as opposed to humans, to get diseases of chronic stress like ulcers, heart disease, and depression. The obvious answer is that they don’t have chronic stress, which is something a good number of us do have. Zebras have to flee the lion or hyenas, or they end up like this guy. They don’t have to worry about a love life, lack of sleep, or a nauseatingly boring job.
I for one hate my day job and feel sick to my stomach whenever I have to go to work. After reading that book, I’m glad I’m changing professions in a few months. My arterial walls will love me for it, I’m sure.
This got me to thinking about exercise. At the heart of chronic stress is cortisol and other hormones termed gluccocorticoids. They’re what kicks in after the adrenaline.
The interesting thing is that from everything I’ve read, CrossFit WODs and typical strength training doesn’t tend to cause huge amounts of cortisol release. However, long-distance, endurance-based events, which have come to be called “chronic cardio” tend to cause cortisol secretion after the 40 minute window. The thing about cortisol is that it causes blood sugar to rise, which causes insulin to rise as well. I’m not sure it has ever been studied, but I suspect chronically elevated cortisol, even by exercise may decrease insulin sensitivity. I suspect that even more when I see my co-workers who tend to exercise for hours at a time, yet never lose any weight.
Essentially, then, people may be increasing their risk of chronic diseases by participating in long runs and masochistically long workout sessions too frequently. I’m all for a good Painstorm, but not every day.
More thought provoking, I think is that, cortisol in a pregnant mother can have serious consequences for the baby in utero. The author has a whole chapter on why heightened gluccocorticoid levels in utero is dangerous for the baby. I’d never even thought of the effects that long exercise sessions could have on a baby in utero. Very interesting stuff and I highly recommend everyone who is stressed out to read the book.
Maybe Robb Wolf will come out to Hawaii and enlighten us on the effects of cortisol.
Post thoughts to comments.
–Nick
