The Dangers Of Going Too Fast

Updated– According to an editorial published online in the BMJ journal Heart, running too hard, too fast, and for too long can be dangerous. The same holds true in publishing. The editorial was hastily released ahead of its scheduled publication time after portions of it were quoted in Wall Street Journal article on the dangers of endurance sports. A BMJ representative told me that Heart had not yet found out how the WSJ article gained early access to the editorial, although in the article it appears that the Heart editorialists spoke at length with the WSJ reporter.

In the editorial, cardiologists James O’Keefe and Carl Lavie marshall the evidence suggesting that “extreme endurance exercise may exact a toll on cardiovascular (CV) health.” The authors acknowledge that runners have only a very small risk of dying during a marathon, but “chronic extreme exercise” can induce “adverse structural and electrical remodeling, which offsets some of the CV benefits and longevity improvements conferred by moderate physical activity.”

The authors cite data showing that “improvements from unfit to moderately fit confer dramatic reductions in morbidity and mortality” but that “fitness levels above 12 metabolic equivalents do not seem to translate into additional gains in CV health and longevity.” The authors posit a U-curve, with “couch loungers” on one side and “extreme exercise aficionados” on the other side. They recommend moderate exercise as “the safe and comfortable zone at the bottom of the U curve, which, they say, is the sweet spot for most people. They conclude with a “take home message” recommending that most people limit vigorous exercise to 30-50 minutes per day.

In the WSJ article both O’Keefe and Lavie, former elite athletes with years of intense training, discuss their current moderate exercise regimens. The article also includes an old quote from Kenneth Cooper, the sports physician who helped launch the original aerobics movement: “If you are running more than 15 miles a week, you are doing it for some reason other than health.”

Update– I asked Heart editor Adam Timmis to comment on this episode and whether he thought the Ingelfinger rule (which forbids prepublication publicity about a forthcoming paper) applied in this case. Here is the response I received:

“Embargo breaks are always regrettable, of course. But while the Ingelfinger rule is a worthy one, to apply it in this case would be like taking a mallet to a walnut.

The article in question was a review article- albeit in editorial format-not original research. And there is little or nothing in the piece that is not already in the public domain. Therefore, we think that it would be excessive to withdraw it from publication.”


  1. akismet-9a3458c127f10299f379416f2426a79a says:

    So, did they break an embargo?


    Tapped on my iPhone

    • At this point we don’t know whether it was the authors or the journalist who broke the embargo. Technically there wasn’t an “embargo” because the paper had not even been distributed to the press yet. But the authors were responsible for keeping the paper confidential before publication.

  2. David Swain writing in the Journal of Evidenced-Based Medicine, states that vigotous intensity exercise is essentially safe for coronary heart disease patients


  1. […] other exercise story from last week had a much different conclusion. Editorialists in Heart concluded that although most exercise is good for you, too much exercise can actually be harmful. They may well be right, but there’s never been– and there almost certainly never will […]

  2. […] Earlier this week I suggested that you should limit your high intensity cardio, here is more research confirming what I said that extreme endurance exercise is bad for your heart. […]

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