May 04

Why You Are Not Living Up To Your Potential



A few years ago I did an accidental experiment with quite remarkable results – and profound philosophical implications. Actually the experiment was not accidental, it was quite intentional, but I didn’t realize until afterwards what I was actually testing. I was a year or so into a temporary obsession with racing triathlons and I was trying to collect data using my lactate threshold heart rate. How I got into triathlon in the first place is a story for another day…

Now this is a little sciencey, but a little background is needed to make sense of things if you are not an expert in exercise physiology. Lactate threshold (LT) is basically a measure of the highest intensity level of work you can sustain over a given interval of time. As you exercise at greater intensities, lactate and other byproducts build up in your body, and eventually build up faster than your body can get rid of them. As they build up they act as a negative feedback loop. If you go faster, your body will shut down and fail. Conversely if you go exercise lower than your LT you are leaving speed/time on the table.

There are sophisticated ways to test this in an exercise science lab, but commonly it is estimated in the field by using a heart rate monitor and a trial of work. You typically run or bike at maximum effort for a set time and see what your average heart rate is. Your LT heart rate will be different for each activity, probably relating to differences in blood flow to the recruited muscles and myocardium (heart) with different exercises. I knew what my LT was on the bike, and I was re-testing it on the run.

The reason for doing this experiment is if you know your LT, and the approximate distance/time you are training or racing, you can use your heart rate to monitor and optimize your performance.

The method I was using was a 40 minute time trial at maximum sustained speed, and measuring my average heart rate over the last 30 minutes, similar to this method. The thing is, I already knew what my heart rate should be based on data I collected from my biking and previous less scientific running trials, so I used that as my benchmark.

Now the conditions for my time trial were not optimal. I was in the midst of training hard for a few races, it was at the end of the day after work and my nutrition was not really optimized for racing or speed. I was a little tired and concluded it was probably not going to be one of my better runs, but it was on my schedule and just needed to be done.

iphone 084

I started running. I ran 10 minutes and quickly got my heart rate up to cruising speed. It was hard, but felt sustainable. I hit the record button and started the trial. Now normally running is pretty fun for me, but there is something a little masochistic about forcing yourself to run at high intensity for a set amount of time. It shifts from freedom to oppression and these trials were definitely not my favorite part of training.

About half way through I was getting cranky. My heart rate kept slipping a bit and my brain really didn’t want me to run harder. When the heart rate drifted lower by a few beats I would ramp up the speed to compensate, making myself work just a little bit harder.  I continued this tug of war with my heart rate and effort and just kind of forgot about everything else.  It was just me and the number on my heart rate monitor.*

I could hear my brain in the background protesting. “Hey man, this pace is too much, let’s just coast these last 10 minutes and relax. We aren’t racing, so what’s the point? Why are you doing this to yourself? What are you trying to prove out here?”

The voice kept getting a little louder and more forceful, but I focused on the number. Drift down, speed up, and repeat.

When I got down to about 5 minutes left I felt a certain degree of calm euphoria come over me because I knew I would be done soon. I kept driving the legs forward, lungs burning a bit as they always do on hard runs.

Bam! 40 minutes. It’s over.

Shit. That was hard. I jogged and walked a while and finally glanced down at the numbers and did some quick calculations. I thought maybe my brain was still suffering from diminished oxygen because the numbers made no sense to me. According to the little gps computer on my wrist I just did the impossible.


  • 30 minutes
  • 5.2miles
  • 5:46 min/mi


My best 5k (3.1miles) time ever…in a race…under optimal conditions:


  • 18 minutes 30 seconds
  • 3.1miles
  • 5:58 min/mile


I just ran a 5.2 mile training run under sub-optimal conditions at a significantly faster pace than my personal best in a 3.1 mile race. If I ran this pace in a 5k I  would have destroyed by best time by 35 seconds. If I could have hung on another mile at this pace I would have obliterated by best 10k time by over 2.5 minutes.


This shouldn’t be possible, should it?

What happened today on this run?

Shouldn’t the drive to win a race be more inspiring than a silly number on a heart rate monitor?

It turns out no. I did something that day I had not been able to do in any of my races. I muted the voice in my head; the voice that is designed to protect your body from hurting itself. I managed to temporarily override my operating system and what I thought were the limits of my physiology.


My Brain

When I got home I pulled out a huge tomb on my shelf called Lore of Running by Tim Noakes, MD. I sat my sweaty self in a chair and started reading. This monster is over 900 pages of dense exercise physiology, history and other running science that I consider to be the authority on all things about running. My copy is from 2003, so some of the information is likely outdated as the science is always changing, but a very useful book none the less.

It only took me a few minutes to find what I was searching for; a couple of paragraphs on his ‘central governor model of exercise performance’. In short, performance is determined by several factors related to the body: Coronary artery blood flow, oxygen and carbon dioxide exchange, elimination of waste products, mechanical efficiency, thermal dispersion etc. But most of us fail to approach the theoretical limits of our performance not due to our body, but due to our brain. The heart is the organ most sensitive to critical damage during vigorous exercise and our brain is designed to protect it at all costs. It shuts your body down well before damage can be done. The brain never lets the gears go too fast for too long because the risk is too great.

Here’s a more recent article on the topic:

When someone says ‘that guy has heart’ referring to an athletic performance, he refers to the ability to push oneself beyond what is capable in normal circumstances. It refers to the heart or spirit over-riding the normal limits of the brain.





So what does this all mean?


It implies there are artificial limits to what we are capable of. The limits are sensible, but they are still a bit arbitrary.

I had been putting limits on myself in all those races. My brain put brackets around my performances to try and protect me.

Moving to the more abstract, our brain puts limits on us in other non-physical ways. The voice in our head telling us we can’t or shouldn’t do something is saying this to protect us. That voice is the central governor of our thoughts and dreams. But to whom and why does it do this?


Placing limits on our physiology so our left ventricle doesn’t explode seems sensible, but the limits we put on ourselves in other ways hurts us, and we all do it.


If you pay attention, you will hear the voice in your head constantly creating limits on who you are and what you should be. This is actually designed to protect you, to make sure you don’t stray too far from societal norms.

We have a drive to be similar to others around us in action and beliefs. We have a desire to fit in and not embarrass ourselves. This is a protective measure and has served us well.

The side effect of this is we are not living up to the potential of our existence.

We conform because in the not to distant past nonconformity meant being ostracized at best, killed at worst. We needed our tribe for survival and were expected to be a cog in the machine. We had no choice in who our tribe was, so we evolved to fit in. Even when we ‘rebel’ we do it very predictable and socially acceptable ways for the most part.

But it is increasingly possible for many of us to be ourselves without fear of reprisal. It is becoming easier to live our lives the way we want to and find people that will accept us for whom we are. It has never been easier to connect with people that share our views. We are not limited to everyone within a day’s horse ride. A cheap computer and internet connection and we can find our tribe. We can be different and still connected. Chances are, unless your beliefs and behaviors are so far removed from the mainstream, there are blogs or internet forums that dig deep into the topic you are passionate about.

That voice also limits us because it does not want us to feel the pain of failure. Often we talk ourselves out of something rather than feel any potential future pain. We don’t talk to the girl at the bar, pursue a business opportunity or push our intellectual abilities beyond their comfort zone. Comfort is the enemy of growth and progress.


What could we accomplish if we muted that voice every now and then?


The world has changed faster than our ability to keep up, and some of our defensive mechanisms are unnecessary or even harmful. At a minimum they are deserving of contemplation and good stretch of their boundaries once in a while.

We have less need for this central governor in many aspects of our lives, yet most of us have not figured out how to turn it off. What would we be capable of if we could turn this mechanism off when it clearly was not needed? Could we do this on demand or only by accident, as I seemed to do earlier in the day? In our day to day lives how much have we left on the table by allowing our central governor to take over?


Do the great minds in art and science simply know how to turn off their central governors and create?


I’m not sure anyone has the answers to these questions, but the next time you think you are reaching the limits of what your mind thinks what you can do, stop and question. Maybe you are capable of more than you think. Turn down the volume of others telling you what you should do, but more importantly turn down the volume of that voice in your head.  Listen to your heart and true self to live the life you really want to live.



*Not exactly what you are supposed to do. It turns out you should not pay attention to heart rate during the test, because heart rate is actually the value you are solving for. Had I not focused on my heart rate I would have run slower.


Please share your experiences with limiting beliefs in the comments below.



1 ping

Skip to comment form

  1. Great post. Reminds me of books I have read on Navy SEALs’ hell week, which they describe as 90% mental, 10% physical. Pushing past barriers so often is a matter of believing we can keep going. But even before that, we need to recognize a barrier is in place at all–looks like you discovered this one by accident t how many more do we have that we aren’t even aware of?

    1. Great example. I suspect we limit ourselves in ways we can’t even see, which is what makes it impossible to break out of these patterns.

  2. I enjoyed the science behind your post. A similar concept that I always use to determine my potential is Opportunity Cost. Whether it’s with my time, money, or energy, when I consider what I’m giving up with everything I do, I realize what’s truly meaningful and find ways to achieve it. Looking forward to more great posts!

    1. Yes, opportunity cost is a massively undervalued concept to understand. It is largely an ‘unseen’ cost by most so they don’t realize when they are paying it. Definitely a topic for a future post 🙂

  3. Boy, almost wish I read this post first, but glad I at least read it before my big race. I had my last long training “run” a couple of weeks ago. I did quite a bit of walking actually, but to my defense I did have to hike up down a large, mountain – twice. :O)

    The second loop up was brutal and I really did want to quit and just turn around and start back down, but I just kept pushing forwarding reminding myself I needed this. I needed the distance and the time on my feet to get me ready for the big race. My mind was trying to hard to save me from pain. But I pushed through. My previous training allowed me to recover reasonably well. And now I just wait for the big day to see if all of my training has been enough.

    I will admin to being a bit nervous as this race only has about a 30 to 40% finish rate, but I hope that is because too many people just do not train like they should. Here is hoping that I have done enough and that at the right times, I can turn my mind off and just push through.

    BTW, your times are phenomenal. My fast 5K is 22:36.
    cd :O)

    1. Awesome man, I wish you luck. Nothing like getting that last long training run under the belt.

      When I was doing triathlons a few years ago I learned that when I wanted to give up it was a reminder to eat. Amazing how much more motivated and cheery I got after some sugar 🙂

      1. I will try the “eating” trick. I switched to consuming mostly a powder supplement called Tailwind. So far so good. Your mouth doesn’t feel much like chewing towards the end or even during the middle of long races. It comes packed with 200 calories plus a bunch of other stuff. :O)

  1. […] you know I like to experiment. I have done many interesting and successful experiments with diet, exercise, meditation, alcohol, etc. My most recent experiment was to see if I would successfully run a half […]

Leave a Reply

%d bloggers like this: