Is Extreme Running Bad for Health?

Hi! I am the author and founder of Old School Calisthenics
extreme running bad for health and heart

As an avid long-distance runner and swimmer, I have gained extensive knowledge about endurance sports over the years. Swimming, in particular, is an incredibly challenging sport due to the higher resistance of water compared to air. For many years, I spent more time swimming than walking on my feet, which is quite an accomplishment in itself.

However, as I got older, I transitioned to bodyweight fitness and endurance running. I pushed myself to run longer and longer distances, eventually running semi-marathons almost daily and even tackling marathon distances in the mountains with elevations over 1000 meters. While I enjoyed the challenge, I soon realized that running such great distances too frequently was taking a significant toll on my body.

I noticed a stark difference between running 21k and twice that distance. Even if running a half-marathon felt safe, healthy, and achievable, running 42k in the mountains was a completely different story. My body felt completely depleted after kilometer 24 and by kilometer 35, my condition was even worse.

Despite my passion for endurance sports, I now know that my body is not built for extreme running. This realization led me to question whether consistent extreme running can damage the heart and body. I also became curious about the effects of long-distance running on my body, particularly the amount of time it took to recover after a hard running session.

As I discovered through recent studies, extreme running can indeed have negative effects on the heart. Studies have shown that ultra runners tend to have bigger and calcified hearts compared to those who run moderately. Of course, there are exceptions, and many extreme runners have managed to maintain their health and fitness over the years. However, it’s important to remember that not everyone is built for extreme endurance sports.

In fact, as you will see in the video below, the average person is not designed to run and endure extremely long distances. It’s crucial to listen to your body and recognize your limits to avoid potential damage to your heart and overall health.

Train Running Tones Calves

Running for me is not about covering long distances anymore. I find that running more than 24k is no longer enjoyable but rather a test of my ability to withstand pain. In my case, the pain does not increase linearly mile after mile, but rather logarithmically. Nowadays, I prefer to run in moderation, between 30 to 90 minutes or between 4 and 15 kilometers, and I thoroughly enjoy my cardio sessions.

This moderate approach to running is sufficient for developing a healthy cardiovascular system and maintaining a fit and lean physique. Additionally, running at a moderate pace allows me to focus on improving my form and running technique. I can also make my running sessions more exciting by incorporating different training methods such as fartlek training or mixing steady pace running with sprints and calisthenic exercises.

The same goes for swimming. I no longer swim 7-15 kilometers per session as I used to. Swimming for 2-3 kilometers is now sufficient for me.

Does Extreme Running Damage the Heart?

Based on my personal experiences and various studies, I strongly believe that extreme running can have negative impacts on one’s overall well-being. My assumptions are supported by the findings of cardiologist Dr. James O’Keefe, who shares similar concerns regarding the health risks of ultra-endurance running.

During his TEDx Talks presentation titled “Run for Your Life! At a Comfortable Pace and Not Too Far,” Dr. O’Keefe discusses the dangers of heart calcification caused by extreme endurance running, as well as the potential reduction in life expectancy associated with such training.

I highly recommend watching Dr. O’Keefe’s presentation, as his insights are both fascinating and informative. His extensive knowledge on the topic can greatly benefit those interested in endurance running and its potential impact on their health.

Does Running Really Increase Longevity?

Dr. James O’Keefe’s argument against extreme running is rooted in a misconception that completing a marathon makes you immune to heart attacks, which many physicians still believe. If performance is prioritized over health, discussions about wellness in relation to ultrarunning are futile.

While many people view extreme physical exercise as a means of relaxation and well-being, the reality is that excessive training can lead to erosion, rather than improved health. Instead, it’s essential to train to sustain good health, and Dr. O’Keefe believes that extreme endurance athletics do not align with this goal.

Dr. O’Keefe’s conclusions are based on his own findings, as well as numerous studies, including the “Minimum amount of physical activity for reduced mortality and extended life expectancy” study. In fact, he conducted a CT scan on his friend John, an avid runner, which revealed concerning results about the impact of excessive running on heart health.

CT Scan for ultra runners
Source: YouTube Video

John’s cardiac scan revealed a score of 1800, indicating severe heart calcification. According to Dr. James O’Keefe, a score above 0 is considered abnormal, and above 400 is considered severe. A normal cardiac scan should not have any calcium present in the arteries.

The question arises: can severe heart calcification shorten life expectancy? While exercise is essential for optimizing health and increasing life expectancy, Dr. James believes that it’s not a matter of survival of the fittest but rather survival of the moderately fit. In fact, further attainment of peak performance does not translate into further increases in life expectancy.

It’s important to note that exercise, like any drug, has an ideal dose range. Taking too much of it, such as engaging in excessive endurance exercise, can be harmful and potentially fatal, as evidenced by the deaths of many ultrarunners.

A study conducted by the Taiwan Department of Health Clinical Trial and Research Center of Excellence and National Health Research Institutes on over 400,000 Chinese found that moderate exercise, such as walking for 15 minutes a day or running for 30 minutes three times a week, can increase life expectancy by up to three years. However, excessive exercise can have the opposite effect and lead to a shorter life span. Read the study here!

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


The study found that a reduction in prolonged vigorous training is associated with better health outcomes. Further physical efforts and training time did not appear to translate into further improvements in life expectancy. The green line, which is associated with light and moderate physical activity, such as daily walking or regular movement throughout the day, was found to be beneficial for health. However, moderate activity was found to be more beneficial than light activity. Although vigorous training was found to be highly beneficial for health, excessive exercise can have negative effects on life expectancy. Therefore, while exercise is essential for maintaining good health, it’s crucial to avoid overdoing it and finding a healthy balance.

“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 Ideal Dose of Exercise: Finding the Sweet Spot

As Dr. James O’Keefe explains, there is an ideal dose of exercise that we should aim for to maintain optimal health. While excessive endurance exercise can cause the heart to age prematurely, moderate exercise can provide numerous health benefits.

As a coach for both amateur and professional athletes, I recommend finding the sweet spot in your exercise routine. This will depend on your level of fitness and goals. It’s important to incorporate both moderate exercise for 30-60 minutes and vigorous training for short durations to produce results in muscle building, fat loss, and overall endurance.

When it comes to strength and conditioning training, I keep my sessions under an hour, including break time. Consistency and gradual performance improvement over time is key. To create an effective training plan, start with a set of fundamental rules that promote health and results, much like a constitution for a country. Read about these principles in “6 Commandments for a Right Training Philosophy.”

While being a couch potato is not recommended, neither is overtraining. Strive to find a healthy balance in your exercise routine to achieve optimal health and fitness.

The Tragic Death of Ultrarunner Micah True: Insights from Dr. James O’Keefe

Micah True, also known as the White Horse, was a remarkable ultrarunner known for his ability to run hundred-mile races. Tragically, he passed away at the age of 58 while out for a run in the Gila Wilderness.

According to his Wikipedia page, Micah True failed to return after setting out for a 12-mile run in March 2012. He was found dead a few days later, and the autopsy revealed that he had idiopathic cardiomyopathy, which had caused his heart’s left ventricle to become enlarged.

Upon analyzing the pathology report, Dr. James O’Keefe believes that Micah True’s enlarged and thickened heart with scar tissue is a condition that some extreme endurance athletes develop, known as Phidippides cardiomyopathy. This term was coined in research conducted by Peter A. McCullough and Justin E. Trivax. The tragic death of Micah True serves as a reminder of the potential risks associated with extreme endurance training and the importance of finding a healthy balance in one’s exercise routine.

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)

Finding the Optimal Running Distance for Health

Dr. James O’Keefe suggests that running more than 25 miles per week may diminish the benefits of exercise. To increase life expectancy, he recommends jogging at a pace of around 10-15 miles per week, with 2-5 running sessions per week.

The Copenhagen City Heart Study recommends running at a slow to average pace for a total of 1-2.5 hours per week and 2-3 runs per week. The study found that moderate joggers had a 44% reduction in mortality and lived 6 years longer than sedentary individuals. By finding the optimal running distance and pace, we can increase our chances of leading a longer and healthier life.

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