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Extreme exercise: Tour de France cyclists live longer

June 21st, 2011

A little bit of exercise is good for you, but too much is bad for you. That seems to be a fairly widespread societal view — certainly anyone who trains seriously as a runner or cyclist or other endurance athlete is familiar with all the comments about how training so much can’t be good for you. And to be fair, there has been some recent research that raises questions about whether running multiple marathons over an extended period of time can damage your heart.

So I was very interested to see a study, forwarded by Brian Taylor (thanks!), that just appeared in the International Journal of Sports Medicine. Spanish researchers decided to study the records of cyclists who rode the Tour de France between 1930 and 1964 — an example of “extreme” exercise if ever there was one — and see how long they lived compared to the general population. They focused on riders from France, Italy and Belgium (who comprised 834 of the 1229 riders for whom birth records were available), and they compared the longevity of those riders to the general population from their home country in the year of their birth. Here are the aggregate results in graphical form:

The trend is pretty clear. The age by which 50% of the population died was 73.5 for the general cohort, and 81.5 for the Tour de France riders — who, according to the paper, ride about 30,000 to 35,000 km per year (though I’d be surprised in the riders competing in the 1930s were training as hard as modern riders).

So what does this tell us? Well, as in any case-control study, there are plenty of limitations on the conclusions we can draw. First of all, this doesn’t prove that “extreme” exercise is better than “moderate” exercise. It may be that riding 30,000 km/year is significantly better than doing no exercise at all (or than doing the relative pittance that the average modern person does), but is still worse for you than riding, say, 10,000 km/year. But it’s pretty clear that extreme levels of aerobic training don’t shorten your life. As the authors put it:

In our opinion, physicians, health professionals and general population should not hold the impression that strenuous exercise and/or high-level aerobic competitive sports have deleterious effects, are bad for one’s health, and shorten life.

It’s also worth mentioning some potential confounding factors. The paper notes that former athletes tend to smoke less, drink less alcohol and have a healthier diet than the general population. Fair enough: these factors almost certainly contribute to the increased longevity of the riders. Again, the conclusion we can draw isn’t that extreme riding makes you healthier; it’s that it doesn’t make you less healthy.

What about genetics and selection bias? Maybe the Tour de France riders tend to be the type of lucky person with a great metabolism who’s destined to be healthy for his entire life no matter what he does, and it’s those great genetics that predisposed him to become a competitive cyclist. Again, not an unreasonable point. In response, the authors point out a 2010 British Journal of Sports Medicine paper in which researchers in Sweden compared the genetic profiles of 100 world-class male endurance athletes (“Olympic finalists or Europe/World Champions and Tour de France finishers”) with 100 matched controls. They looked at 33 “risk-related mutations and polymorphisms” associated with cardiovascular disease, hypertension, insulin resistance, cancer, and other major causes of mortality — and found no difference:

[T]he overall picture suggests that there is no evidence that elite male world-class endurance athletes are genetically predisposed to have a lower disease risk than non-athletic controls. Thus, the previously documented association between strenuous aerobic exercise undertaken by elite athletes and increased life expectancy is likely not biased by genetic selection.

Bottom line: if the question is “How much exercise is too much?”, I still think the answer is “Way, way more than you think.”

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  1. June 21st, 2011 at 16:35 | #1

    Interesting data. Wonder how it will look in a few decades when the drug era riders start to be factored in to the stats?
    DaveL.

  2. Seth Leon
    June 21st, 2011 at 18:29 | #2

    Thanks Alex,

    That study finding no genetic differences related to those various is interesting, and something I might not have guessed. It certainly strengthens the finding of increased life expectancy in the athletes.

  3. alex
    June 21st, 2011 at 22:03 | #3

    @David: Indeed! The paper mentions this in its discussion section: “We have to keep in mind that our data are limited to 1964 which is perhaps before the time some of today’s most dangerous drugs were used, e.g. anabolic steroids, blood doping, etc.”

    @Seth: Yes, very interesting study — I’d missed it when it first came out last year, so I was glad this new study pointed me in the direction of the genetics study.

  4. Phil Koop
    June 22nd, 2011 at 15:07 | #4

    It is possible that the cyclists of this study trained less distance than modern pros; for one thing, many of them would have worked at other jobs in winter. However, pro cyclists in the pre-modern era were obliged for financial reasons to spend much more time racing (rather than training) than modern riders. Even in Merckx’s time, a decade after the end of this study, it was normal to race 180-200 days a year – unthinkable today. Consider that in running terms; it is one thing to cover a marathon distance on your feet, something else again to race it.

    Modern drugs are vastly more effective but not necessarily more dangerous than those used before 1964, which included amphetamine. During the period of this study, amphetamine wasn’t even proscribed.

  5. Phil Koop
    June 22nd, 2011 at 15:14 | #5

    Also: modern Tours are usually under 3,500 km total distance, whereas Tour distances peaked at over 5,000. The hardest 1-day races are now around 260km (MSR is an oddball at 300), whereas the 300+ distances were not unusual. Paris-Bordeaux was about 560. The trend has been to quality over quantity.

  6. Zave Dabriskie
    June 22nd, 2011 at 18:11 | #6

    @David Lovgren
    Drug era? The history of endurance sport is littered with drugs. This is not a new issue, just a much more publicized one.

  7. Mike
    June 22nd, 2011 at 20:31 | #7

    Of the many athletic events, I am so glad to see this study. Cyclists have a few advantages that may contribute to longevity. First and foremost is the their cervical(neck) curve reinforcement. Like an infant that never gets tummy time to develop the lordosis in the neck, has more health problems. Cyclists get more “tummy time” than anyone and hence have a very strong cervical lordosis of the cervical spine and healthier organs. Second, low impact on the joints. I think the trend will continue in follow up and future studies.

    I think if further studies on cyclists investigated which conditions they did encounter more would include lumbar disc herniations, pelvic organ dysfunction and foot and leg neuropathies. This would be due to the positioning of the lumbar spine while riding. A straightening or even reversal of the lumbar lordosis would biomechanically be consistent with cycling resulting in a stretching of the cauda equina portion of the spinal cord and nerves.

  8. oldskoolroadie
    August 24th, 2012 at 13:08 | #8

    @alex

    However, not before the days of amphetamines, coke, etc. To say that old time riders weren’t using is just plain sentimental lunacy.

  9. Eli
    September 28th, 2012 at 17:57 | #9

    The guy who wrote this is probably fat.

  1. June 22nd, 2011 at 17:13 | #1
  2. June 23rd, 2011 at 00:48 | #2
  3. May 10th, 2012 at 06:26 | #3