Tag Archives: Jesse Thomas

Episode 6: Heart Rate Training and Racing, Training Zones, Geoffrey Kamworor & RunScribe, Coaching and Racing at same event, etc.



In episode 6 of the Art and Science or Running, Coaches Malc Kent and Jacob Puzey discuss the pros and cons of training and racing by heart rate.

Malc explains the two fundamental ways to measure heart rate:

  • The classical mode – with a chest strap has two key parts or electrodes on the back of the device to pick up an electrical signal of the heart pumping. In theory, it’s a very simple algorithm of how many peaks were measured in one minute (BPM). However, the simple algorithm depends on the person’s heart. Not all hearts are created equal. Algorithms can be refined to better isolate peak signal of the heart, but that requires knowledge of how the algorithms work.
    • One tip for improving signal pickup with a classical heart rate chest strap is to wet the sensors with saliva or water prior to adhering to the body.
  • Since 2013 there are now optical wrist heart rate sensors which measure different colours of oxygenated blood. This way of measuring heart rate sends out light which in turn is disturbed by a wave of energy in the blood vessel of oxygenated blood. However, this means of measurement is still not as accurate as the traditional electrocardio (chest strap) method.
  • We often hear from our athletes that their optical heart rate data is either off by 5-10 beats per minute or goes in and out in the first few mi/kms of a run. This means that athletes need to be prepared to mentally clean up data when they review it after a run and not rely too heavily upon it during the run.
  • One additional problem with optical heart rate accuracy is that it doesn’t work as effectively with darker tones of skin or tattooed skin.  For more details about this, please read Fitbits and other wearables may not accurately track heart rates in people of color.
  • Read more about the Firstbeat technology contained in most major watches at

    All in a heartbeat: How Firstbeat became the secret sauce in your fitness wearable – The company trying to turn your heart rate into personal feedback

Trail and ultrarunning coach and author, David Roche discusses some of these challenges in his article: Why You Should Be Skeptical About Your Wrist-Based Heart Rate: Wrist-based heart-rate technology is not perfected yet, and it varies based on the watch and athlete.

Malc, who has worked with some of the major players in the watch and wearable technology space, explains that major watch company use published academic papers to formulate algorithms as a means of avoiding liability and litigation:

“When you see something on a watch, that isn’t you specifically. That is a very very simplistic model or algorithm that originated with some studies that didn’t take into extremes from around the world so you have to take it all with a pinch of salt.” – Malc Kent

Most of these studies are very small populations of runners in controlled conditions.

These studies are based on the generally accepted equation that Max Heart Rate = 220 BOM – Age

Both Jacob and Malc explain that they are both outliers for most algorithms. Malc has a small heart and therefore a very high heart rate which means his lactate threshold is also high. Jacob in contrast has a very high VO2 Max, but his lactate threshold is relatively low compared to his VO2 Max.

Jacob shares examples of other outliers in the sport who also happen to be engineers and understand their unique datasets and use their own understanding of their bodies to inform their training and racing:

Gary Gellin is 51 years old and is one of the top trail and ultra athletes in North America. Despite his age, Gary has a Max Heart Rate in the high 190s to low 200s. Consequently, Gary’s lactate threshold is also quite high. Gary is a Stanford educated engineer known for his strict adherence to running by heart rate. In fact, Gary taught Jacob how to run by heart rate early in Jacob’s ultrarunning career. Gary knows the math for his own body and has recorded his own data and created his own ranges.

Malc explains that the heart has an electrical signal that will naturally oscillate even if you switch the brain off for some time which means that there may be certain individuals like Gary who may be able to exceed otherwise normal thresholds of control over the deep brain.

Another example of an outlier in the heart rate realm is Jesse Thomas a Pro Triathlete, Stanford educated engineer, founder of Picky Bars, and podcaster with wife, Lauren Fleshman, on the Work, Play, Love Podcast. Jesse and Lauren are both elite athletes and have been since their teenage years. Jacob ran in the same conference as Jesse in Oregon. Jesse was a multiple time conference and state champion before moving on to run at Stanford. Jesse explains that unlike many other elite endurance athletes he has a really low max heart rate. Both Jesse and Lauren explain what training metrics to use in Episode 28 of the Work, Play, Love Podcast.

Max King is a Cornell educated engineer who also understands his heart rate and body very well. Max’s athletic range is unparalleled in endurance athletics. He has been a world-class 3,000m Steeplechaser, Warrior Day World Champion (5K), XTERRA World Trail Run Champion (Half Marathon), National 50K Trail Champion, Olympic Marathon Trials Qualifier, World Cross Country Championship qualifier, World Mountain Running Champion, World 100K Champion, and course record holder of many trail and ultra races around the world.

Jacob recalls watching Max run the Western States 100. He passed through the half way point several minutes up on the next runner and people were encouraging him to slow down. He was running at such a conversational pace that he was able to calmly explain that he could run any slower. His heart rate was an easy 135 BPM.

Read more about Max King’s superhuman accomplishments in Taking It to the Max: An Interview with Max King.

Malc and Jacob agree that like these elite outliers, the best approach to understanding one’s own heart rate algorithm is to collect a lot of data for a long time so that you can look back and determine what your zones are relative to relative perceived exertion.

Malc has always had the philosophy that heart rate has a place to control easy runs – to very quickly bring attention to the fact that someone is training too hard.

Jacob finds heart rate especially helpful in group settings as a means of regulating effort.

Use heart rate effort in racing as a means of controlling effort, metabolism, predict fuelling, etc.

Jacob describes one of his best ultra experiences using heart rate to control effort and fuelling at the Mt. Hood 50 on the undulating Pacific Crest Trail.

Heart rate won the day that day. Focussed on nutrition and controlling the effort. This was Jacob’s second 50 miler, but unlike his first one in which he relied entirely on effort and the heart rate of Gary Gellin, Jacob used his own heart rate data to control effort and focus on fuelling.

“If you are using the heart rate zones assigned by an app or a training system, it is likely not tailored to you, but a rather simplistic way of looking at it. If you have tons of personal data to create your own zones that is best.” – Malc Kent

Heart rate doesn’t take into account where your body is at or where your nervous system is at. Heart rate measuring devices are better for regulating effort (keeping you from running too hard), but if doing intervals, it doesn’t respond quickly enough and therefore it is not accurate enough to account for the variability (lag time, etc.)

There aren’t simple, basic rules. You have to embrace the complexity of it. Part of this is why Jacob and the Peak Run Performance coaches design training plans with a color continuum as well as some of the overlapping efforts. The overlay of heart rate zones work well with rate of perceived exertion, polarized training, 80/20, and the nordic skiing models that Matt Fitzgerald and Stephen Seiler discuss. They have gathered data from best endurance athletes in the world from their training intensities and suggest that amateurs should aim for similar ratios in training.

When it comes to watches, heart rate monitors, and other wearable technology it best to read the owner’s manual and learn how to use it and the limitations of the tool so that you can use it more effectively.

All of this and more in Episode 6 of the Art and Science of Running Podcast.

Intro and outro music by Dallin PuzeyGOIN 4 A WALK.

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