Is Extreme Running Bad for Health?

Hi! I am the author and founder of Old School Calisthenics

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As a long-distance runner and swimmer, I certainly know enough about endurance sports. Swimming is one of the toughest out there simply because water opposes a much higher resistance than air, and over the course of several years, I used to swim a lot more than I walked on my feet, which is no little thing to do.

Later in my life, after I stopped swimming, I moved to consistent bodyweight fitness and endurance running. I continued to do so until I found myself running semi-marathon distances almost daily. If this wasn’t enough, I also started to run marathon distances in the mountains with elevations of over 1000 meters.

Consequently, I came to realize that running such great distances too frequently beats my body too severely. I felt a huge difference between running 21k and twice the distance. In fact, if running 21k felt doable, safe and healthy simultaneously, even if it’s not quite like that, running 42k in the mountains didn’t feel like that at all. It didn’t even feel twice as hard since I felt absolutely eroded after kilometer 24. Don’t even ask about my condition after kilometer 35.

Now I know for a fact that I am not made for endurance sports, let alone extreme running. However, this experience raised my curiosity about whether extreme running can damage the heart and body if done consistently. I also became curious about what happens with my body during and after long-distance running because every time I went for a hard running session, I needed a lot of days to recover.

And as you will find out from this article, recent studies report that extreme running can calcify and thicken the heart. Many studies were conducted, and ultra runners displayed a bigger and calcified heart compared to athletes who run moderately. Exceptions exist; plenty of extreme runners made it to early ages and still run and feel well. After all, everything is relative. However, average people aren’t built to run and endure extremely long distances, as you will find out by watching the video below.

Train Running Tones Calves

For me, running more than 24k isn’t enjoyable but rather a test of stoicism to see if I’m capable of resisting pain, which by the way, it doesn’t increase linearly in my case but rather logarithmically mile after mile. Nowadays, I run in moderation, between 30 to 90 minutes, or between 4 and 15 kilometers and I now really enjoy my cardio sessions. I honestly find it sufficient to develop a healthy cardiovascular system and a fit and lean physique. Running moderately, I can concentrate on improving my form and running technique. I can also spice up my running sessions by doing short and vigorous running mixed with relaxed jogging, called fartlek training. Or I mix steady pace running with flat or uphill sprints and various calisthenics exercises.

The same goes for swimming. I don’t swim 7-15 kilometers a session anymore like I used to back then. Swimming for 2-3 kilometers is absolutely sufficient these days.

Does Extreme Running Damage the Heart?

What I believe to be true about extreme running concerning well-being is arguably real as it’s all based on genuine self-experience and studies. However, I found a cardiologist, dr. James O’Keefe, sustains my assumptions that ultra running is unhealthy and can reduce life expectancy.

During a TEDx Talks presentation, dr. James spoke about heart calcification caused by ultra-endurance running, life expectancy, and how extreme training could eventually make you unhealthy and reduce life longevity.

I invite you to watch his presentation because his discoveries are very interesting, and I think you could benefit from his erudition. The video is called: Run for your life! At a comfortable pace and not too far:

But running is supposed to add years to your life! Isn’t it?

The whole argument of dr. James O’Keefe is based on the urban myth proclaimed boldly by a cardiologist in the mid-70s that you would be immune to a heart attack if you could complete a marathon. In his opinion, a lot of physicians still share the same wrong judgment.

Suppose performance is far more important than health. In that case, talking about wellness in relation to ultrarunning is all in vain.

I can’t but witness one fact: far too many act like their extreme physical exercise is essentially about well-being and relaxation. This is my own assumption. In reality, once you are very healthy, more sport isn’t going to get you more health. Exaggeration and extreme running will get you to erosion. You should train to sustain health instead, and honestly, running 100 miles every week has nothing to do with sustainability, considering you already own optimal health.

I think that a good cardiologist should find the ideal diet and lifestyle that supports health, right? Dr. James O’Keefe came to the conclusion that extreme endurance athletics do not fit into this recipe. His judgment is based on his own discoveries, plus many other conducted investigations! See the following study: Minimum amount of physical activity for reduced mortality and extended life expectancy.

Dr. James did a cardio scan (a CT scan), simple and non-invasive, on one of his friends, John, who was obviously running all the miles in the world. This procedure is a high-tech scan of the heart, and the results are below:

CT Scan for ultra runners
Source: YouTube Video

John scored 1800. Now, according to dr. James, everything above 0 is abnormal, and above 400 is severe; at 1800, John’s arteries are harder than his bones are! A normal cardiac scan shouldn’t have any calcium whatsoever in the arteries. He also didn’t have any other risk factors to speak of, quoting from doctor James!

Can this shorten life expectancy?

First, a habit of daily exercise optimizes health. Thus, it’s a substantial measure of increasing life expectancy. Dr. James says it is not the survival of the fittest. In fact, it is the survival of the moderately fit. He claims that further attainments of peak performance do not translate into further increases in life expectancy.

Exercise is an amazing drug, but just like any drug, there is an ideal dose range. If you don’t take enough of it, you don’t get the benefit. If you take too much of it, it could be harmful, maybe even fatal. Many ultrarunners died spontaneously.

Now let’s move to a study. This is what the Taiwan Department of Health Clinical Trial and Research Center of Excellence and National Health Research Institutes found in a study conducted on over 400000 Chinese:

Vigorous Running versus Light and Moderate Running
Figure 1: Daily physical activity duration and all-cause mortality reduction


Please read the study because I merely summarized the outcome here. So, the more reduction from prolonged vigorous training, the better. Further physical efforts and training time do not appear to convey further improvements in life expectancy. The green line is associated with light and moderate physical activity, meaning daily walking or day-to-day moving around. More moderate activity is better, so definitely stop being sedentary! The only thing is that light activity is not quite so beneficial as vigorous training. Therefore, you could exercise all day, it seems, if you keep it down.

“Compared with individuals in the inactive group, those in the low-volume activity group, who exercised for an average of 92 min per week or 15 min a day, had a 14% reduced risk of all-cause mortality and had a 3 year longer life expectancy. Every additional 15 min of daily exercise beyond the minimum amount of 15 min a day further reduced all-cause mortality by 4% and all-cancer mortality by 1%. These benefits were applicable to all age groups and both sexes and to those with cardiovascular disease risks. Inactive individuals had a 17% increased risk of mortality compared with individuals in the low-volume group.”

The Dose Makes the Poison

As explained by doctor James, there is an ideal dose of how much sport we should generally do. We are not really meant for these sustained levels of exercise for hours a time. Practically, the heart becomes older before its time due to years of extreme endurance running.

My Recommendation!

I coach amateurs and professional athletes on a daily basis. My recommendation for you is to find the sweet spot if you are not into a career where performance is everything that matters. It also depends a lot on how adapted or fit you are. So run, ride the bike or swim moderately for 30-60 minutes. In fact, do vigorous training too because you need hard work to produce a sufficient stimulus for results in muscle building, fat loss, building athleticism or general endurance, but keep these intense workouts short.

Almost every time I do conditioning and strength training via calisthenics or running, I keep my sessions under 1 hour (break time included). On top of all, I am pretty adapted to daily training. I increased my performance gradually and over a very long period of time through consistency. You don’t need more than 30 minutes to do strength or high-intensity training.

You should start by conceiving a good training philosophy with fundamental rules to help you build an effective training plan that promotes health and other results. One that works like a constitution does for a country. You never go beyond these few key principles, no matter what. Read about it here: 6 Commandments for a Right Training Philosophy.

Two things I do not recommend are turning into a couch potato or training like a maniac. Could you be somewhere in the middle?

The ultrarunner, Micah True, who died under suspicious circumstances

First and foremost, the White Horse, Micah True, was an outstanding runner, legendary for his ability to run hundred-mile races. He died, sadly, at the age of 58.

As his Wikipedia page reveals, Micah True failed to return on March 27, 2012, after heading out for a run in the Gila Wilderness. He departed from the Wilderness Lodge in Gila, saying he was going for a 12-mile (19 km) run. On March 31, True was found dead and based on the autopsy report, True was suffering from idiopathic cardiomyopathy, which had caused the left ventricle of his heart to become enlarged. 

However, Dr. James O’Keefe looked at the pathology report and believes that Micah True’s enlarged thickened heart with scar tissue is a pathology some extreme endurance athletes develop termed Phidippides cardiomyopathy by Peter A. McCullough in research conducted with Justin E. Trivax.

According to McCullough and Trivax’s hypothesis, “this pathology occurs because endurance sports call for a sustained increase in cardiac output for several hours” which puts the heart “into a state of volume overload. It has been shown that approximately one-third of marathon runners experience dilation of the right atrium and ventricle, have elevations of cardiac troponin and natriuretic peptides, and in a smaller fraction later develop small patches of cardiac fibrosis that are the likely substrate for ventricular tachyarrhythmias and sudden death.” (Source: Wikipedia)

How much should we run for health?

According to Dr. Jame O’Keefe, benefits go away if we run more than 25 miles weekly. Ideally, we should run around 10-15 miles a week at a jogging pace to increase life expectancy and with a frequency of 2-5 running sessions weekly.

The Copenhagen City Heart Study recommends running at a slow to an average pace, between 1-2,5 hours a week and 2-3 runs a week. The study reveals that moderate joggers got a 44% reduction in mortality. They live 6 years longer than sedentary people.

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