Really, Really Long Bouts of Exercise May Be Bad for You


You’ve heard exercise can be good for you, but can it also be bad for you? Maybe! But before you set about burning your running shoes and letting the sweet, delicious smell of synthetic fabrics massage your brain into a semi-psychotropic state of euphoria, you ought to consider the caveat to this apparent win for indolence: only really, really excessive exercise might be bad for you. Think about that the next time you decide to do something reckless and train for a triathlon or something.

The Wall Street Journal recently featured an initially encouraging article about the possible cardiovascular havoc excessive endurance training regimens can wreak on the unsuspecting triathlete, marathon runner, or Iron Man. Exercise, like everything else, is good, but only in moderation, or only if it’s not performed excessively to the point where one’s heart just throws up its arteries and shouts, “I quit!”

According to the latest and greatest research into the effects of distance running, the benefits of running may start to diminish once a person hits the 30-miles-per-week mark. That heavy load of endurance training can put runners (and the Journal article focuses almost exclusively on distance runners) at higher risk for truly nasty-sounding things like “an enormous aortic aneurysm,” a condition that, while not caused by endurance training, could be exacerbated by it. The risks of over-training, however, don’t end there:

Other recent studies suggest the significant mortality benefits of running may diminish or disappear at mileage exceeding 30 miles a week and other, very small studies have shown elevated levels of coronary plaque in serial marathoners—a problem that rigorous exercise theoretically could cause.
“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?” said John Mandrola, a cardiac electrophysiologist and columnist for

However, sports-medicine specialists have been reluctant to discuss these newer findings because it can quite easily make for borderline-sensationalist media fodder (much like what you’re currently reading), and give otherwise sedentary people a really good reason not to exercise. The truth is, the vast majority of humans aren’t ever going to do the 30-plus miles of endurance training per week that could precipitate any cardiac problems, and it’s important for researchers to discuss the negative effects of overtraining, especially considering how preventable they may be.

The moral of the story is, obviously, exercise moderately. In fact, just do everything moderately — smoke a few cigarettes everyday, have a few drinks, eat a few pieces of cheesecake, and maybe watch just a few hours of television. Best to be cautious about these things.

The Exercise Equivalent of a Cheeseburger? [WSJ]

Image via AP, Firdia Lisnawati

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