Questions about Running and Heart Health

As runners, we’re accustomed to hearing that we’ll “ruin our knees” and other nonsense, usually from someone who uses that colloquial wisdom as an excuse to be a couch potato. And although I find those people to be irritating, their assertions don’t trouble me. Given the alternative of being a couch potato, I think my knees are better off belonging to a healthy-weight runner, thank you very much. Yes, every time someone makes a comment about running ruining my knees, I want to say something snarky like, “I hope that can of soda doesn’t ruin your pancreas.” So yes, I still find the insinuation oddly annoying. However, it doesn’t give me anxiety because I’m at peace with my choice and its relative risk/benefit to my joints.

However, not too long ago, in a place not too far away, I heard some disturbing news. I heard that maybe running (specifically running high mileage) wasn’t so good for your heart. At first glance, it sounded like a high quality piece of sensationalist fake news. Then I heard it a couple more times. And finally, I heard a physician friend whose opinion I trust, also refer to the study that reported this warning. He felt that the science had been sound, and that sure enough, there was a limit (and not all that high a limit) to how much cardiovascular exercise would benefit us before turning into a risk. Specifically, the turning point was around 20 miles per week. Any amount of running up to approximately that amount was considered beneficial, but after this amount, the cumulative strain on the heart muscle might just be harming more than helping.

Research led to claims that running too much was actually as bad as being sedentary and could lead to increased mortality.

Nuts.

This has led me to ask several more questions, most starting with the basic root question of, “Does my heart have a finite number of beats?” In other words, I’m curious to know whether anything that speeds up my metabolism and my heart rate is really just accelerating me towards that greatest of all finish lines. When I drink two cups of coffee and I can actually feel my heart rate quicken, is that killing me? When we talk about the benefits of increasing our metabolisms by adding muscle mass to lose weight, are we wasting heart beats? Taking days off our lives?

Observational studies of populations known for their increased longevity usually find as association with low calorie intake. Well, how do you suppose they’re maintaining such low calorie diets? They’re not bulking up for fitness competitions, that’s for sure. You can only survive on a low calorie diet if you’re not expending too much energy. In other words, they had relatively lower metabolisms. Most of their physical activity came from being steadily active at a low intensity throughout the day rather than from intense and focused workouts. They lived slowly, but not lazily and only ate as much as they needed to sustain that lifestyle. Did their hearts last longer because of it?

My first experience with these concerns was actually long before I’d heard of any of these studies, and perhaps before some of them had even been done. I ran my first (and to date, only) full marathon in 2003, and for several months afterwards, I experienced premature ventricular contractions or PVCs. These are relatively common phenomena, but they were new to me, and I had no explanation. It felt like my heart would beat and then pause for a little too long, then respond to that long pause with a beat that was a little too hard. It was as if, instead of beating on time, it saved up it’s next beat for an extra second so it could give me a two-for-one beat on the next go-round. And it was disturbing as hell. I used an electrode monitor for a day, then tried one later for a month. I learned that, yes, I was having PVCs, but luckily none of my doctors felt that there was a reason for concern or treatment. And sure enough, after several months, they seemed to stop happening except for every once in a while, like much of the population.

If I hadn’t had that experience, I’m not sure whether these recent studies would have piqued my interest so much, but ever since then I’ve been curious to know – did running a marathon cause this to happen to me? Or was it just coincidence? So far, most of the data I’d consumed had reassured me that although running a marathon, for example, does result in some acute damage to the heart muscle, it is fully recoverable, and shouldn’t result in any lasting damage, given the proper rest afterward. I found that reassuring, until I started hearing the warning bells about high mileage running.

I turned to my trusty resource, Runner’s World Magazine, and www.runnersworld.com for answers, and as usual, they were there for me. RW writer, Alex Hutchinson provided a much more moderate interpretation of the studies in a couple of RW blog posts. (1, 2) After reading what he had to say, I was reminded of the caution that always needs to be exercised when interpreting statistics. With evidence that isn’t fully conclusive, it bears mentioning that there may be risks associated with running high mileage beyond those that we’ve traditionally accepted, but so far, it seems that we can’t say with any great detail what that precise mileage number is and how it might vary based on individual factors.

That was great and all, but I took the most solace in a more recent article that I was alerted to, also from Runner’s World. In this article, Amby Burfoot discusses a study published by a cardiologist and lifelong distance runner in which he reports observations on serious runners he has known throughout his life – runners who have racked up far more miles than I ever will. And guess what? When it comes to longevity, they are kicking the collective asses of the general public.

From Runner’s World, These Serious Marathoners Lived 19 Years Longer Than Average. The study author, Dr. Rosin, genuinely took a serious look at the question posed by recent research, and he was qualified to do it. This is a brief article that is WELL worth the read. Even if you weren’t worried about running and heart health, if you’re a runner, it just feels good to hear some good stuff about your fellow-runners, and to remember that overall, we’re probably doing something great for ourselves. And if you’d like to read the original study by Dr. Rosin, you can find it here.

So yeah, you could say that gives me hope. Everything carries risk. Turns out, you could overdose on beta-carotene from eating too much health food, but I don’t know of any cases where that’s happened. And I’m going with the following rationalization. I believe the running makes me healthier for several reasons.

It helps me maintain a healthy weight.
The exercise helps me sleep better at night.
The endorphins contribute to an improved outlook and make me tolerable to be around.
I get other great mental health benefits. For example, being a part of the running community gives me a social connection which is extremely important for mental health. And having a hobby that I’m passionate about helps make me happy!
Running outside gives me a chance to make some vitamin D.

So yeah, everything has two sides, but there are enough plus-sides to running that I’m taking my chances and sticking with it.