Let's call June 30 the halfway point of the year (and it also happens to be my half-birthday, something I remember mattering when I was 3 and 4 years old and a half year was a huge portion of my life).
This half year, I have logged 2050 miles. That's a lot of miles. A lot more than half of my total from last year (3162 miles). Maybe this is because I haven't tapered--and then recovered--from a marathon yet this year, which can make for 2 very low-mileage months.
2050 miles. I should note that somewhere around 100 of those miles were "hiked". If I did the math right, that is an average of 11.3 miles every day. That is an average of 80-90 minutes of running/hiking a day.
Let this be my bi-annual super congratulations to myself for all these wondrous miles and number crunching!!!
Actually! Quite the contrary. I'm sharing this as a good starting point to explore a new and potentially very scary and serious medical finding that makes my high mileage the opposite of congratulatory: distance running may be fucking up my heart and could ultimately lead to me dying at a younger age than someone who runs less. So not cool.
I've never run with the motive of extending my life. Sure, running has cardiovascular benefits and is generally believed to be healthy, but I've never thought, "the more I run, the longer I will live!" Therefore, these recent studies aren't exactly spinning my world on its head.
But it is really worrisome and frightening to read that my #1 hobby may be detrimental to my longevity.
Well let's dive into the study. It's about to get medical in here.
The Mayo Clinic recently released an article about the negative health consequences of endurance training. Several weeks ago my dad (the anti-runner) sent me an early abstract of the study. Then, more recently, a friend who practices medicine and is also a running enthusiast shared the article with me, as well as his early thoughts on the subject.
Pulling the language of his email and some of the study excerpts, the findings were as follows:
A 15-year observational study of 52,000 adults found that runners had a 19% lower risk of all-cause mortality compared with non-runners. (So far, so good!). Running distances of about 1 to 20 miles per week, speeds of 6 to 7 miles per hour, and frequencies of 2 to 5 days per week were associated with lower all-cause mortality, whereas higher mileage, faster paces, and more frequent runs were not associated with better survival. (In short: for optimal survival, run slowish, not too far, not every day).
Studies also analyzed the effects of long-term long distance running via MRI results of 102 ostensibly healthy male runners from ages 50 to 72 who had completed at least 5 marathons during the previous 3 years. These results were compared with 102 age-matched controls.
The comparison found that about 12% of the marathon runners had evidence of "patchy myocardial scarring"--which was 3-fold more common than in the control group. (I think this means running more than one hour regularly can lead to "something not good for your heart").
In conclusion, in some individuals, long-term excessive endurance training may cause adverse structural and electrical cardiac remodeling, including "fibrosis and stiffening of the atria, right ventricle, and large arteries." Cardiovascular benefits of vigorous aerobic endurance training appear to accrue in a dose-dependent fashion up to about 1 hour daily, beyond which further exertion produces diminishing returns and may even cause adverse cardiovascular effects in some individuals.
My Doctor Runner Friend noted that the studies raise some disturbing questions that are particularly worth considering for younger runners, who still have the chance to halt any potential damage.
There is a long list of questions to still be answered here (especially relating to how these findings relate to women, and how to identify signs that a runner may be at risk), so I don't think anyone needs to quit running longer than 60 minutes at a time. I certainly don't plan on quitting long runs anytime soon. I wouldn't even know where to begin. But I am anxious to learn more. In the world of running, the rules and facts seem to change by the year, so we can't jump off ship just yet.
Disclosure: I was paid a stipend by the anti-runners association to write this review. I'm kidding. This review is depressing! Please share your thoughts, experiences, and your knowledge.