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.

Conclusion

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!