John Davis

Written by John Davis


Is Running High Mileage Bad for Your Health? A Response to Media Scrutiny on “Running Too Much”

Last week, we took a look at the types of running injuries that ultramarathoners suffer.  Though they largely get the same injuries as “regular” runners, there are a few interesting differences that might have something to do with the prodigious volumes of running that ultramarathoners do.

While injuries are obviously a concern for any runner, a bigger question about high mileage, long training runs, and races is how running higher mileage affects your overall health and well-being.

There’s been a lot of back and forth recently about this issue.  It’s well-established that a moderate amount of exercise keeps you healthy and helps you live longer.  But the effects of what some people call “extreme” exercise are uncertain.

Some research has suggested that a major loads on your body, like running a marathon, can produce transient stresses on your cardiovascular system, which may translate into more permanent damage.

On the other hand, other research suggests high-volume exercise incurs no lasting harm.

In this article, we’ll further examine one major study that attempts to answer the question on whether running high mileage is actually healthy for you.

How high mileage impacts a runners’ health

The Ultrarunners Longitudinal Tracking Study, or ULTRA for short, was designed in part to help answer the question: “Is running high mileage bad for you?”

To do this, the ULTRA study will follow 1,212 ultramarathoners for a very long time, probably until the end of their lives, to see how their exercise habits affect their health.

The study was undertaken only three years ago, so the biggest question marks—the effects of high-volume running on cardiovascular health and lifespan—remain unanswered. But, there is still a lot to be learned from the preliminary survey of the health history of the ultra runners in the study.

The average participant in the study was 36 years old, confirming that most ultramarathoners (and especially the faster ones) tend to be older than your typical 5k or 10k hotshot.

Ultramarathoners are also a pretty experienced bunch, as the majority of the subjects in the study had been running for at least seven years before they competed in their first ultramarathon.

Overall, ultra runners as a whole are a pretty healthy bunch.

  • The study’s participants only missed 2.2 days of work or school in the last year because of injury or illness, compared to 3.7 days among the general population.
  • And the ultramarathoners were confined to bed only one day out of the past year because of an injury or sickness versus 4.7 days among the general population.
  • The ultra-runners had a low, although not nonexistent, incidence of high blood pressure and irregular heartbeats, with about 7.5 percent of the runners reporting one of those problems.
  • Less than 1 percent had been diagnosed with heart disease or had a past stroke, and few had experienced cancer, with basal cell skin carcinoma being the most common malignancy, occurring in 1.6 percent of the runners. Those percentages are generally lower than among age-matched American adults, especially considering that a majority of the ultra-runners were aged 40 or older.

Even when you control for the fact that ultramarathoners tend to be better-educated and more likely to hold office jobs, these trends still hold.

Even though 77% of the runners in this study suffered a running injury during the past year, they visited the doctor less often than non-runners.  And among the doctor’s visits that the runners did incur, nearly two-thirds were only because of a running-related injury.

This is not to imply that the ultramarathoners in this study were perfectly healthy.

How healthy are ultramarathoners?

As you’d expect with any decently large cross-section of the population, a handful of the subjects in the ULTRA study were diabetic, asthmatic, HIV positive, cancer patients, living with cardiovascular disease, and so on.

  • A total of 28% of the runners took medication for some type of medical condition.
  • The incidence of virtually all medical conditions was lower in the ultramarathoners than in the population as a whole.
  • The only two exceptions to this were asthma and allergies or hay fever.  Around 13% of the ultramarathoners had exercise-induced asthma, and 25% had allergies or hay fever.

Among the general population, these numbers are 8% and 7%, respectively.

Both asthma and allergies are known to be more prevalent in endurance athletes, probably because of their increased exposure to allergens and pollutants in the air.  It shouldn’t be too surprising that ultramarathoners, who inhale large volumes of whatever is in the air where they run and compete, have a higher rate of these two conditions.


The running habits of the subjects in the ULTRA study appear to confer some remarkable health benefits, at least in the short term.

The group as a whole averaged 2,080 miles in the past calendar year—40 miles per week—which is pretty impressive for a group of over 1,200 runners.

These ultrarunners missed fewer days of work, needed less medical care, and had a lower incidence of pretty much every serious medical condition compared to the general population.  Notably, however, allergies, hay fever, and asthma are bigger concerns for the ultramarathoning community.

We’ll have to wait a while to see whether this trend of good health continues for the runners in the ULTRA study, but what does this suggest for you, right now?

Despite the attention-grabbing headlines you’ll read in the New York Times and other such magazines and papers, running higher mileage and training for marathons and half marathons does not seem to negatively impact your health and well-being.

Of course, we’ll need to continue to follow the runners in this study, but right now the data shows running higher mileage is good for you!

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1.Lucia, A.; Hoffman, M. D.; Krishnan, E., Health and Exercise-Related Medical Issues among 1,212 Ultramarathon Runners: Baseline Findings from the Ultrarunners Longitudinal TRAcking (ULTRA) Study. PLoS ONE 2014, 9 (1), e83867.
2. H offman, M. D.; Chen, L.; Krishnan, E., Body Mass Index and its Correlates in 1,212 Ultramarathon Runners: Baseline Findings from the ULTRA Study. Journal of Physical Activity & Health 2013.
3. Helenius, I.; Tikkanen, H.; Sarna, S.; Haahtela, T., Asthma and increased bronchial responsiveness in elite athletes: Atopy and sport event as risk factors. Journal of Allergy and Clinical Immunology 1998, 101 (5), 646-652.

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7 Responses on “Is Running High Mileage Bad for Your Health? A Response to Media Scrutiny on “Running Too Much”

  1. I have been running ultras for many years, i am now in my fifties and my body is falling to bits, my knees and back give me grief, I have heart issues and stomach, sports phsio and specialist both have stated from excessive please do be careful.

    • Thanks for the insight, but we are sorry to hear that. There is only a limited amount of miles that our bodies can handle, ultras most likely mean that we get to that limit sooner. Hopefully you can still do some running, but if not, telling your story will be great for those around you! Let us know if we can do anything to help!

    • I currently am doing a research paper on the effects of marathon running on the body. I would love if I could interview you for my paper since you seem to know about the negative effects very well. Email me if you’re interested! Thanks!

  2. Thank you for replying. I used to love to run,geez I miss it but if I knew them what I know know I would have taken it easy and run for fun instead of taken it so seriously. Have a very lovely day . Matilda.

    • Sorry to hear that Matilda, isn’t that always the case. It is true what they say, you have to make your own mistakes, and those setbacks happen for a reason. At least you have those warm memories to look back on, and know that you at least got to experience it. Now you can share your experience with others, and get at least some enjoyment out of that 🙂

  3. I read the article and would like to say I am 64 (in August) and started running over 40 years ago. In that period of time I have 80,000 miles of running on my feet. I mostly ran in the 5-10-15 miles range. I did run a few unorganized marathons and ran only two organized half-marathons when I was just about 59-years-old.

    I always felt that running 26 miles at once was too much for the human body so I kept my miles during a run at a distance I felt comfortable with…usually between 10 and 15 miles.

    At age 60 I did develop a small tear in my mensicus…I stopped running for a couple of years and started body building at a gym during that time. Then one day I realized the pain in my knee was gone and tested the waters again for running. Happily I am able to say I am back to running again and running six miles a day for four days a week. I think the reason is because I stopped running for a couple of years while I strengthened the muscles around my knees that made it easier for my knees to avoid a lot of the impact of my running and take pressure off of them…I still weight train to keep the muscles around my knee strong. 64 in August and still loving my running while weighing 135 lbs with a heart rate some times lower than 50. I recently ran a treadmill mile at 6-minutes and could have ran it faster.

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