The Dangers of Excessive Cardio

29 05 2013

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I’m sure many of you are already thinking it, so let’s get it out of the way: Here Dain goes again, ripping on cardio. Indeed, I’m not a cardio guy, but my bias has nothing to do with this post; even if I’m not a fan, a reasonable amount of cardio has nothing but positive health benefits. Let’s recap a few things:

  1. Almost any kind and any duration of exercise is better than no exercise at all
  2. Weight training is simply more efficient than cardio for burning fat, has very similar (if not equal) cardiovascular health benefits, additional functional strength gains, and more desirable body composition results
  3. Regardless of the activity, excessive habits can lead to problems

In general, I’m never going to advise anyone against good habits like exercising and drinking a lot of water, but even though these are examples of healthy activities, if done in excess they can lead to serious health issues.  A friend brought this Wall Street Journal article to my attention the other day, The Exercise Equivalent of a Cheeseburger?, and it inspired me to write this post. The Coles Notes:

  • Although cardio is healthy (improved blood pressure, cholesterol, longevity, etc.), endurance athletes (or anyone running more than 30 miles/48 kilometers a week) are at an increased risk of atrial fibrillation and developing coronary-artery plaque.
  • Anecdotal concerns about endurance athletics have been building for years and cardiac conditions that required surgery have forced into retirement two winners of the Ironman Triathlon World Championship.
  • Research shows an association between endurance athletics and enlarged aortic roots.Cardiotoxicity-Cycle-Chart
  • Heart disease comes from inflammation and excessive exercise causes inflammation. Why wouldn’t there be a link?
  • Doctors are afraid to say that any kind of exercise may have a negative effect, for fear of giving people an excuse to stay sedentary.
  • Long-term excessive endurance exercise may induce pathological structural remodeling of the heart and large arteries.
  • Parallels can be drawn to the dangers of over-hydration, which was once seen as impossible- the more water the better. Long after evidence emerged that over-hydrating could prove fatal to marathoners, experts continued encouraging runners to drink as much as possible, and the dangers were not fully believed until deaths had occurred.

Now don’t get me wrong, I’m super guilty for living life in extremes- for example, I’ve got a strongman competition coming up in a few days, which is pretty much the definition of excessive. I completely understand the desire to push the human body as far as possible, but common sense should still reign supreme; Along with my penchant for lifting heavy things, I’m diligent with prehab and rehab exercises, I eat extremely well, I sleep plenty, and I supplement my lifting with lots of brisk walking and recreational sports. I schedule annual physical check-ups with my family physician to make sure my health is where it should be (my blood work couldn’t look better, in spite of my “extremely dangerous” dietary habits of eating half a dozen eggs daily and embracing saturated fats) and I’ve been living this lifestyle now for almost a decade, so I feel pretty strongly that my exercise habits, although sometimes excessive, aren’t harmful.

Research like this only serves to enhance my personal opinion that competitions like marathons are of the most detrimental activities to human health. We all have our own individual reasons to push our bodies, but I’ll never understand the desire to run excessive distances when the end result will surely be skeletal overuse injuries and damage to my cardiovascular system; not to mention the muscle-wasting that will reduce my strength and wilt my physique.

If you haven’t already seen it, there is also a pretty good TEDxTalk on this subject. Cardiologist Dr. James O’Keefe’s conclusion? Balance and moderation; shocking, I know. If you have 18 spare minutes, give it a watch:

If you are a marathoner, or someone who engages in any sort of excessive activity, I implore you to consult your physician to ensure that you don’t have any underlying cardiovascular health issues. The jury is still out on exactly how much cardio is detrimental to human health (we are still likely years away from truly understanding the line between beneficial and detrimental amounts of cardio)  but it is without argument that a pre-existing health condition can easily be life-threatening if undiagnosed prior to excessive exercise.

In the end we’re all going to do what makes us happy in this life, so I just want to make sure that we’re all aware of the pros and cons of excessive exercise, and that these activities are done in the most responsible way possible.