Ultra Running: Telomere Augmentor or Destroyer?

Pistol Ultramarathon John participated in.

“I’m training for a 100 mile ultramarathon,” I told my date, a first, at a lively restaurant with a great atmosphere in lower Manhattan called El Vez.

“Wow, that’s incredible!” she replied.   “I’ve competed in a few marathons and have just begun training again after recovering from an injury, but I can’t even conceive of trying to run an ultra.  How many marathons have you completed?”

“None,” I admitted.  “In fact, I’ve never even run a half marathon or a 5K for that matter.  On December 7th (about a month before this conversation), I ran my first mile since high school which was over 20 years ago.  It was brutal!”

“Seriously?  And you think you will be able to complete an ultra?  When? Three years from now?”

“No.  March.  I may try to complete a fifty miler as a warmup in February.  You don’t seem to think I’ll be able to do it.”

“That’s insane.  There’s just no way that’s even possible.  Don’t even bother trying. You’ll never finish and will probably seriously injure yourself just trying.”

This conversation was playing through my head as I struggled to fall asleep at a Hilton in Knoxville, Tennessee, the night before I was to begin running my first ultramarathon.  I thought to myself, “Maybe this wasn’t such a good idea. I am not confident I can get through it. Is the pain, suffering, and injuries I’m no doubt about to endure really worth it?  I don’t even know if this will affect my telomeres at all.”

You are likely wondering why a 41 year old guy fixated upon reversing his biological age would spend the time and effort competing in, and training for, an ultramarathon.  Allow me to explain. I suspect my explanation may be of great interest and it will all begin to make sense. You may even wind up with an urge to give ultrarunning a shot.


“[A]n ultrarunner’s mind is what matters more than anything. Racing ultras requires absolute

confidence tempered with intense humility.” (Scott Jurek, “Eat & Run” 2012)


The Darkside of Ultrarunning

I hate running.  I’ve never liked it one bit.  It is arguably the absolute worst form of self abuse imaginable.  Don’t misunderstand me; I love sports and exercise, just hate running for the sake of running.  It always seemed rather pointless to me. Why run when there are so many other more fun and interesting forms of cardiovascular exercise?  Cycling, tennis, racquetball, swimming, rowing; anything but running! It is terrible on the joints and it’s dangerous. Yes, it is truly dangerous.  I’ve heard of countless men and women dying on the side of a road after suffering heart attacks because of jogging. Furthermore, some studies estimate that 90% of runners will miss training time in a given year due to injury.1  The amount of cortisol and oxidants that get generated on a run is staggering.  Considering this as well as the effects running has on the endocrine system, a compelling argument can be made that running actually accelerates aging.  

If running is dangerous and unhealthy, ultra running is certain death and destruction.  This group of lunatics have crossed the line from exercise for the sake of health, fitness, and enjoyment to an obsession with driving themselves to accomplishing the nearly impossible.  For them, training injured and pushing forward in a state of constant, agonizing pain is just part of the challenge and the price they are willing to pay for a small slice of glory. That glory is objectified in the form of a belt buckle awarded to 100 mile finishers commemorating their accomplishment.

It’s virtually impossible to train seriously for ultramarathons and not negatively affect your endocrine system.  Under normal circumstances, if you’re eating well, getting enough sleep, and exercising like a normal person, your hormones will work to self regulate and maintain a near optimal balance. Ultra runners often throw that balance seriously out of whack by overtraining.

Cortisol is an anti-inflammatory and a catabolic hormone that breaks down cells.  It is the “get up and go” hormone that is released upon waking. Too much training releases too much cortisol, which breaks down too many muscle proteins.  The ultra runner is continually dumping cortisol into their bloodstream, not for a mere hour or two, but for 10 and 20 and 30 hours at a clip. The hormonal effects on the body are devastating.  It’s not just cortisol that is affected, too much training also decreases levels of testosterone. Testosterone, found in both men and women, increases muscle mass and decreases recovery time. But while intense workouts can increase testosterone levels, too much training can drive them down.2  

Chronic overtraining shortens telomeres and decreases life expectancy.  It’s an accepted fact. For ultra runners, it is super easy to overtrain.  In fact, it’s hard not to in order to prepare to conquer the amazing distances they face.  Most “experts” seem to universally agree that ultrarunning is extreme, unhealthy, and just generally “bad,” primarily because of how common overtraining syndrome is in the sport, but also because of injuries, endocrine system issues, and wear and tear on joints from “overuse”.  


Ultrarunning often causes injuries


The Paradox

If ultra running is so bad for one’s health, how does one explain how the average ultra runner has telomeres the average length of someone an incredible Sixteen Years younger?  We seem to have a perplexing paradox.

I first came across ultra running’s association with extremely long telomeres in Dr. Blackwell and Dr. Epel’s book “The Telomere Effect.”  Here is a link to the actual study.  If one’s telomeres are the average length of the average person sixteen years younger, one is, biologically speaking, 16 years younger.  I remember being stunned as I read that. The fact also confused me because another part of the book seemed to argue against ultra running as it explained the experience of a woman who had significantly shorter telomeres as a result of over training for the Grand Slam of Ultrarunning.  Becoming a Grand Slammer, a feat only a handful of people rise to each year, involves the completion of three of four of the most prestigious and challenging ultramarathons in a single year, including the famous Western States Endurance Run. “What gives?” I pondered, “Either ultrarunning is or isn’t good for one’s telomeres.  Which is it?”

I also found it both strange and disappointing that this astonishing fact about ultra runners’ telomeres was covered in a single paragraph.  As soon as I read it, I had about 50 follow up questions. Most importantly, “Why are ultra runners’ telomeres so long?”  Here we have an activity that seems to reverse one’s biological age by an astonishing 37% and a mere stinking single paragraph is devoted to this mind blowing fact?!  Scientists around the world should be studying this to determine effective methods of managing and conquering aging. Entire books could and should be written about this fact!  Why isn’t it igniting more imaginations as it has mine? What should be front page news is instead categorically ignored. Why? Because there is no money in it! Yet, if the same results from this free activity could be delivered in a fantastically profitable pill, it would be front page news in every corner of the world and the pill would be worth hundreds of billions of dollars.

My curiosity and interest in telomeres forced me to begin looking further into this matter.  I decided if the mainstream scientists, medical professionals, and other experts weren’t going to examine this, I would.  That’s when I vowed to attempt to complete an ultra marathon during my year long quest. Even if I failed to successfully complete one, I’d learn a great deal about ultra running.  I also wouldn’t be too upset if I failed because I’d be in really good company.

As I continued devouring books and began training to run 100 miles, I discovered that my interest in the association between ultrarunning and very long telomeres was not unique.  In fact, a leading mind and celebrity in the field of biogerontology also seems to share my point of view. Dr. Bill Andrews, CEO of Sierra Sciences, reportedly runs an ultramarathon a month.  He is one of the main characters in the documentary about defeating aging called the “The Immortalists”. You can see the movie trailer below:

Initially, the more I read about, studied, and actually ran, the less the fact about ultra runners’ telomeres made sense to me.  I was utterly baffled. One evening, after running 40 miles that day, a giant cyst had formed behind my right knee. I was in agony and could hardly walk.  “This can’t possibly be healthy,” I thought to myself. “There must be some mistake with the study I keep thinking about.” But I pressed on and eventually concluded that overtraining is very unhealthy and will unquestionably shorten one’s telomeres.  I further concluded that the average ultra runner probably should have short telomeres not only because of the overtraining, but also because of all the oxidative and endocrine system damage. And yet, we have this paradoxical fact. Their telomeres are longer than average, not just by a little bit, but significantly longer.  That means they will live longer/healthier lives. Well then, how can anyone say it is unhealthy? Is what is “healthy” what will lead you to live the longest functional life? Or is it something else?

It seems to me, ironically, if one is  “ultra” careful to avoid not only overtraining, which is very easy to do, but also injury, which is also extremely common, ultra running is arguably the very “healthiest” activity one can engage in.  There is no other known activity, supplement, therapy, or drug that will lengthen telomeres as much. Consequently, and inexplicably, despite the shin splints, excruciating pain, giant bursting blisters, cramps, diarrhea, puking, ravenous hunger, dehydration, strained tendons and ligaments, baker’s cysts, runner’s knees, and occasional hallucination,  it is, nevertheless, unquestionably, healthy. What other group of people have telomeres so long? None, that I am aware of. This could be the key to firing the first shot in the battle to conquer aging! More resources should be devoted to studying this phenomenon.

I believe ultra running must be linked with a recurring theme at ReversingMyAge.com;  hormesis.  Hormesis is a phenomenon of dose response relationship in which something that produces a harmful biological effect at moderate to high doses may produce beneficial effects at low doses.  When one lifts weights, muscles suffer micro tears. If one gives one’s muscles time to properly heal, they will slowly grow stronger as one continues to increase the dose of the stress (weights/reps).  The same principle applies to ultra running. Don’t run 100 miles your first day out, but gradually increases the stress (distance/pace) and eventually running 100 miles won’t be unfathomable. Sooner or later one’s mind and body will grow accustomed to the stress.  

I have an easy, accessible solution to the overtraining issue that plagues the sport.  Heart Rate Variability (HRV). I take an HRV reading each and every morning to start my day.  It tells me EXACTLY how my central nervous system is doing and what the likelihood of overtraining is.  It tells me when it is safe to raise my intensity and put the hammer down, and it tells me when I should lay off.  It even tells me when I should do nothing but yoga or breathing exercises. HRV is a magnificent tool because it objectively measures everything affecting one’s autonomic central nervous system and gives users a window into areas that would otherwise remain hidden from view.

One of the primary motivating factors in my decision to run an ultra was that aside from calorie restriction, I believe ultra running may well be among the most compelling, proven, ways to reverse one’s biological age.  This begs the question, why does ultrarunning lengthen telomeres? I really don’t know. It may not for everyone. The potential explanations are practically limitless. Though, if adequately analyzed, researchers are capable of figuring it out and pinpointing the main mechanisms involved.  Nevertheless, I am using it as one of many tools to lengthen my own.


Heart Rate Variability is a useful tool to combat overtraining in ultra running



Ultrarunning really is the perfect metaphor for life itself.  It’s got everything; pain and suffering, joy and glory, darkness and light, fear and confidence, and relationships with which to get through the hard times and celebrate the good.  Just as in life, one must suffer in order to experience a great reward. Without the low lows, there can be no high highs. Completing an ultra was really, really difficult; likely the hardest thing I ever did in my life.  That is precisely what makes the experience so personally valuable. Many fail to see the connection. I now believe if I can suffer through an ultra, I can get through just about anything.

According to Outside Online, “a record 36,000 people participated in [ultra-distance events] in the U.S. last year.  Given a U.S. population of 313,914,040, that means that those who participated in an ultra-distance event were 0.0115% (rounded up) of the total population.”3  As such, it is an incredibly small group of people.  They are, though, very friendly as a group and equally easily accessible.  I issue a call on scientists and aging researchers to begin studying this special group of people to determine, precisely, why their telomeres are so long.  Ultrarunning is simply not a young person’s sport and it is not uncommon to see a 70 year old blazing through a 100 mile race. It is high time we begin learning something from these special septuagenarians.

So, you’re all wondering.   Did I manage to finish the 100 miles and did I do it fast enough to earn a belt buckle?  I sure did and just by the skin of my teeth because I made the cut off time by 9 minutes.  It took me 29 grueling hours 51 minutes and 19 seconds to complete. It felt more like a month.  Here is a link to my official time.  As you can see I was the dead last male runner.  I may have walked quickly for large portions of the race, but I finished it, resulting in one of the most satisfying experiences of my life.  I genuinely mean that. Will I do it again? Had you asked me that during the race, I would have quickly replied with a decisive, “No,” and proceeded to try to run away from you in an effort to choke off the conversation.  However, if you ask me that now, my response is an equally decisive, “Hell Yes!” I plan to try to tackle my next one sometime this summer. Hopefully my body will have recovered by then and my telomeres will have grown much longer.    


Belt Buckle John Loehr earned after completing the 100 mile Pistol Ultramarathon.


1  Reynolds, G. (2016, February 10). Why We Get Running Injuries (and How to Prevent Them). Retrieved March 25, 2018, from https://well.blogs.nytimes.com/2016/02/10/why-we-get-running-injuries-and-how-to-prevent-them/

2 The Role Of Hormones In Running. (2014, May 15). Retrieved March 25, 2018, from http://running.competitor.com/2014/05/training/the-role-of-hormones-in-running_57112

3  Lessons from the Ultra(Running) Fail of Tim Ferriss. (2016, July 09). Retrieved March 25, 2018, from http://www.zhangschmidt.com/2013/04/lessons-from-the-ultrarunning-fail-of-tim-ferriss/


  1. Bart Deshotels

    Pretty great post. I just stumbled upon your weblog and wanted to say that I’ve really enjoyed surfing around your blog posts. After all I will be subscribing for your rss feed and I’m hoping you write again soon!

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  3. Michelle Bartlett

    Your whole website is so inspiring and full of great information. But mostly, I’m totally stunned by your running story in this post. Its absolutely amazing. I can’t begin to comprehend how you have gone from zero running to 100 miles in less than 4 months. It seems impossible. I would love to hear more information about what your training was like and what you ate to support those volumes of running. How did you get through the injuries. I have so many questions. I’d really love to hear more from you about this ultra running journey.
    Thank you so much for doing all this work and sharing the results with all of us. I’m sure there are so many people who will benefit from your efforts. I can’t wait for your next update.

    1. Post
      John Loehr


      Thank you so much for your very generous comment!

      Though I went from zero to 100 miles in under four months, I did not begin with a totally clean slate. Going into December 7, my first mile run, I had been cycling like a maniac. I actually believe I was fitter when I was focusing on cycling than I am now. An explanation for why I believe this would be incredibly involved and I haven’t fully worked out the “why” yet. I hope to be able to elaborate on this in the fall.

      The methods I used to train for my first ultra amounted to me basically stumbling around in the dark. My way is definitely NOT the “right” way. In fact, most experts would agree that I did just about everything wrong. I do not recommend increasing your distances as fast as I did. It is a recipe for injury.

      My training plan consisted of nothing extraordinary. I kept going to the gym doing 5×5 three times a week, though it was probably more like 2 times a week. I did yoga and breathwork regularly. I took cold showers. I tried to run somewhere between 2 and 10 miles two or three times during the work week. I then performed a very long run once a week to once every other week. My long runs were between 20 and 50 miles.

      I believe my meditation practice had a lot to do with my success. It’s definitely not for everyone, but once I figured out how to do it, it has really enabled me to get control of my mind and emotions. The first 50 miles are physical. The last 50 are psychological. Meditation really helped me get through the last 50.

      One absolutely critical training trick I used to get through 100 miles is, believe it or not, walking. Ask a marathon runner to walk 50 miles. He or she probably won’t make it. Adding walking to my training made a huge difference because the walker is using a different set of muscles than the runner. I walked A LOT. Everyday. It sounds silly, but everyone who runs ultras, even the pros, walk for periods. I wanted to complete an ultra, not win it. As such, I knew that with a 30 hour cutoff, I could comfortably walk very long stretches of the race and still finish on time and earn that coveted belt buckle. So, during my training I actually focused on going slower and farther. I never let my heart rate get above 138.

      Eating and fuel is a complicated issue; one that I continue to struggle with. I was convinced that the optimal diet for longevity is intermittent fasting mixed with KETO. My reasoning is eating the least amount of carbs and/or eating only carbs with the smallest glycemic load is best for longevity because insulin, I believe, is a hormone that speeds aging. So, as I was training, I spent several weeks testing my blood ketones and glucose levels. I was very strict and doing quite well. I struggled to find things to eat on my weekend long runs and ultimately settled on Generation Ucan, a relatively expensive powder that is a very slow burning fuel. I trained myself to be able to comfortably run 15 to 20 miles needing literally nothing to eat or drink.

      That all sounds great, but the problem was I felt so weak and tired on fasting days. Sometimes I was so tired, I had great difficulty convincing myself to do anything at all after work. I also suspected my testosterone levels had plummeted and found myself getting weaker. Ironically, and annoyingly, my bodyfat levels weren’t dropping as quickly as I had expected. Eventually, I decided that I was definitely running the pistol ultra marathon so I had better get myself physically and mentally prepared as best as possible. I didn’t have much time left. Keto and intermittent fasting, it seemed to me, just created another challenge for myself rather than something that was originally adopted to make it easier. So, I went back to what my DNA test said is the optimal diet for me; the Mediterranean Diet.

      While I was intermittent fasting on a 5:2 schedule, I switched to and am now practicing intermittent fasting by compressing my eating window to something like a 17 hours of fasting with a 7 hour window of eating schedule. I eat whenever I want on weekends. I’m definitely heavier, have gained body fat, but I am stronger, my muscles are fuller, and my testosterone levels feel more normalized.

      During the race, I pretty much ate whatever I wanted at the aid stations. I was not only looking for fuel, but also comfort in food. Quesadillas, ham and turkey mini sandwiches, grilled cheese, and meatballs were all things I enjoyed during the race. I never stopped moving or to hang out at the aid stations. I grabbed some food and kept going. I also ate very light, never stuffing myself. I saw several people puking during the race. I did not eat any candy or anything with sugar. I drank only water and an electrolyte drink. I carried protein bars and gels in my vest. It killed me to use them, but I used the gels every hour for the last few hours of the race.

      I still don’t have the answers as far as what the optimal eating/fasting/food choices are with respect to both longevity and ultra running. It is an ongoing process of discovery that I hope slowly, but surely improves.

      Please always feel free to ask any questions you may have about what I’m doing. But remember, I’m no expert and just figuring out what works for me as I go. You are just as likely to come up with a better way of training, so don’t be afraid to share your own thoughts and/or suggestions.

      I’ll be posting my next blog within a few days and hope my next quest update is published within two weeks. I am waiting for the results of my recent telomere test.

      Thanks again for the comment and questions!

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