Friday, April 15, 2011

Marathon for Health?

I've quoted Kurt Harris blog a few times, and now he's "hit the big time" with his blog being published on Psychology Today.  Kurt is noteworthy for being an MD, specifically he's a radiologist, so he's particularly well informed on the subject of this article - how to measure heart damage via imaging.  I recommend that you read the whole article, but he does such a good job of summarizing the subject that I submit that for your consideration.

Of note, my friend Crusader, has been telling me for the last 25 years that jogging is not good for me.  I didn't start to believe him until 2005 or so.  After finding CrossFit in 2007, I stopped "jogging."
Note: Underlining added by me for emphasis.

I think that atherosclerosis is not caused by lack of sustained high-level aerobic ("cardio") exercise.
Just like I don't think lack of "cardio" is the cause of the obesity epidemic.
I think premature atherosclerois is mostly caused by diet. Our susceptibility to a bad diet is contributed to by genetics.
I think that not only does sustained "cardio" not protect you from atherosclerosis, I think it is quite likely that through repetitive shear stress with endothelial damage and promotion of an inflammatory state, that it may promote atherosclerosis and/or direct cardiac muscle damage.

Further, I think that excessive "cardio" might precipitate the thromboembolic and acute inflammatory events like plaque rupture - acute heart attacks, even if it does not directly contribute to atherosclerosis, which I think it does.
Could "cardio" promote atherosclerosis and myocardial damage by being confounded by diet? That is, could the wheat, excess sugar and linoleic acid found in low fat "healthy" diets be more prevalent in marathon runners by virtue of their greater caloric intake of this noxious garbage?
That's a possibility. I think it may apply to cyclists, most of whom seem to eat horribly and who seem to be prone to osteoporosis.
Even if these findings are all confounded by a noxious athletic diet, I still find no grounds at all to believe that high levels of "cardio" protects your heart or makes you live longer. Certainly not "the more the better" which is what we've been led to think since the 1970s running craze.
I think a modicum of repetitive, aerobic-type physical activity can definitely improve your mood. I like to a run about 5 k a few times a week. It feels good and cross-country seems good for your coordination with all the varied terrain. A little cross-country and some sprinting sure seems to make me more functional.
I am not under the delusion that it will dramatically improve my overall health or my longevity, though. And I've seen no evidence that doing it every day or doing 5 times the mileage would be better. Just the opposite, in fact.
Same goes for eating "fruits and vegetables", gorilla levels of fiber, "antioxidants", and most supplements. No magic foods.
The really good kind of exercise, resistance training, makes you more functional and stronger. That is the only sensible definition of fitness if we follow the hippocratic oath with our selves.
Primum Non Nocere
I vote we keep the terminology. We should keep calling marathons, centuries on the bicycle and hours on those ridiculous stairmasters and treadmills "cardio" to remind us which organ we may be putting at risk.
Running a marathon is starting to look about as smart as boxing or playing football.

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