Sunday, May 26, 2013

The Exercise Equivalent of a Cheeseburger?

"Sure, you're happy now, but soon you'll be dead!"
On Friday, a rather interesting article appeared in the Wall Street Journal. Here is the key bit:
Over the last few months, during the endurance-athletics off-season, something extraordinary happened: The line began to blur between the health effects of running marathons and eating cheeseburgers.

"I'm not worried," says veteran running coach Mark Sullivan, who has run more than 150 marathons, joking that "there are guys who live to be 100 smoking cigarettes and eating cheeseburgers."

Endurance athletes have long enjoyed a made-of-iron image. But amid mounting evidence that extraordinary doses of exercise may diminish the benefits of modest amounts, that image is being smudged. That extra six years of longevity running has been shown to confer? That benefit may disappear beyond 30 miles of running a week, suggest recent research.

The improved blood pressure, cholesterol levels and robust cardiac health that exercise has been proven to bestow? Among extreme exercisers, those blessings may be offset partially by an increased vulnerability to atrial fibrillation and coronary-artery plaque, suggest other recent studies.
Now, we here at Sons of Cincinnatus don't just do politics. In fact, both of us have an avid interest in running. Unfortunately, the Elder Son's knees ceased to tolerate their tortures a few years ago, but the younger son (that is, me) continues to run (see picture above). Furthermore, at least 120 of my friends on Facebook list "running" as an activity they like, and dozens of my friends, on and off Facebook, run regularly, both as amateurs and as collegiate athletes. Thus, we found this study to be rather disconcerting, for many reasons. But the equivalence made between the health effects of running and consuming one of modern gastronomy's unhealthiest conveniences affronted most of all. So we decided to take a closer look at the article.


The Elder Son in his running prime, breaking a race ribbon.
First, some preliminary remarks about the author's lead. Let us note that no such thing as an "endurance-athletics off-season" actually exists. We take time off, to be sure, and rest our bodies with easier workouts, but one of the whole points of endurance athletics is to train year-round for, you know, endurance. Furthermore, observe how the author begins with a specialist who accepts his premise rather than rejecting it. Finally, although the "30 miles of running a week" figure may mean little to non-distance runners, it does not really indicate the mileage of more skilled distance runners, such as collegiate athletes and marathoners, who run 2-3 times that amount (or more) regularly.

So far, so bad. But let's look at the construction of the article. As a good journalist, the author (who actually wrote a similar piece a few months back), starts with the salient fact ("RUNNING IS BAD FOR YOU!") and then gets to the less important stuff later. Or does he? For only quotes from certain physicians

The lesson I've learned from 40 years of cardiology is that when there's this much smoke, there's often some fire," said Paul Thompson, a sports-medicine specialist and veteran marathoner who is chief of cardiology at Hartford Hospital in Connecticut. 
Heart disease comes from inflammation and if you're constantly, chronically inflaming yourself, never letting your body heal, why wouldn't there be a relationship between over exercise and heart disease? [Jack: isn't that you're supposed to tell us?]" said John Mandrola, a cardiac electrophysiologist and columnist for TheHeart.org.   
and select anecdotes
In 2011, Ironman winner Normann Stadler underwent emergency surgery to repair an enormous aortic aneurysm, a condition not caused but very possibly aggravated by endurance athletics. Research shows [Jack: what research?] an association between endurance athletics and enlarged aortic roots.

Sports medicine has a history of ignoring warning signs. Long after evidence emerged that over-hydrating could prove fatal to marathoners, experts continued encouraging runners to drink as much as possible—leading to utterly preventable tragedies such as the death of a 43-year-old mother of three in the 1998 Chicago Marathon. "Why did it take 20 years before the original evidence was accepted?" asked a 2006 article in the British Journal of Sports Medicine. [Jack: It's a tragedy, but how exactly is it related?]
before actually getting to the real meat. Here, I presume, is the study on which the article's author really based his attention-grabbing headline:
As director of a decadeslong project called the National Runners' Health Study, Paul Williams has published dozens of scientific articles showing that running—the more the better—confers a variety of robust health benefits. But along with Hartford's Thompson, Williams just completed a study of 2,377 runners and walkers who had survived heart attacks. Over 10.4 years, 526 of them died, 71.5% of them from cardiovascular disease. What Williams found is that the more they ran or walked after a heart attack, the less likely they were to die of heart disease—until they exceeded 7.1 kilometers of running or 10.7 kilometers of walking daily.
Now, I have taken one statistics class in my life, and I did a pretty terrible job in it, but even someone as mathematically illiterate as I am can point out the basic flaw in that study: it relies on quite the selection bias. In trying to determine whether running has negative health effects, it...studies people who have already felt them. It assumes causation, in other words, in its attempt to discern causation. And what is the "research" the author keeps citing?

So this article has problems, to be sure. But one cannot merely dispel its thesis by attacking its flaws--i.e., shooting the messenger. And I think I lack the expertise (or the time) to dissect the findings of these authors fully. In fact, the only claim to any sort of "expertise" I have is that I run as a college athlete. Yet I think that qualifies me enough to make a sort of general statement about studies like this.

One of the more depressing thing about these studies is that they provide an incentive to lazy people. For all the runners, like me, whom this study enraged, a handful of joggers probably decided to cut down on their training a bit, or perhaps give it up completely--a tragedy, as obesity continues to climb.

Aside from that, however, this article actually cuts to one of the greatest dilemmas all athletes face: the cost of success in their younger years. In a way, its a version of Achilles' agony in the Iliad:

For my mother Thetis the goddess of the silver feet tells me
I carry two sorts of destiny toward the day of my death. Either
if I stay here and fight beside the city of the Trojans,
my return home is gone, buy my glory shall be everlasting;
but if I return home to the beloved land of my fathers,
the excellence of my glory is gone, but there will be a long life
left for me, and my end in death will not come to me quickly.
All athletes, especially runners, know that their bodies will not hold up as they did in their youth forever. But a glory exists in running beyond mere achievement, beyond mere "health." It is a truly a lifestyle. Runners of any talent level must dedicate themselves to all sorts of pain and suffering in the short-term, hoping for results in the long-term--an amazing example of delayed gratification when so many have resorted to its instant cousin.

So if long-distance running will bring an early death, a la Achilles, or produce worse health down the road, then I say: bring it on. Certain runners quote Steve Prefontaine rather incessantly, but one his more famous quotes applies quite well:

"The best pace is a suicide pace, and today looks like a good day to die."
Talent in running is a gift, and I intend to use it as far as I can take it--and then a little bit further. For that's what running is all about: taking yourself to your limits, finding out what your limits are...and then breaking them. Repeat ad infinitum. Someday, I may be ready to accept a life without running. But right now, I can't imagine it.

So I won't.

I'll just keep running.

Walking is too boring anyway.

1 comment:

  1. Jack (and Tim),
    Interesting post. One of my favorite quotes is: "Everyopne is entitled to his own opinions but not his own facts." I think the author of the WSJ article doesn't get it. I choose to keep working out and running. Isn't exercise better in 99.9% of all cases than the alternative - sedentary life?

    ReplyDelete