Biometric technology and ultrarunning: how it works and how it can help you go the distance

The 50K, 50-mile, 100-mile distance and beyond are all characterized as ultramarathons for the simple reason that the distances are farther than a marathon. 

But it isn’t just the farther distances that set these races apart from a marathon. When going those extra miles, you are often doing them at a much slower, methodical pace. In many of these races you are running, or rather hiking in the mountains, traversing over rivers, or trekking on long dirt paths.  

Rather than burning through sugars and electrolytes like you would a marathon, ultramarathons will require that you go into your fat stores. You will also lose salt and therefore the ability to retain water. You will need to eat while on the go, all while paying close attention to digestion issues that may creep up (or down) in order to complete the goal at hand. 

And there are differences between the two, there is one very important similarity: The need to monitor how your body is responding to your training, in conjunction with outside life factors. How are you sleeping? How is your gate, and has it been altered due to injury or even the change of footwear? How is your heart rate, in particular, your heart rate variability (HRV)?

Unfortunately, very few studies have been done on HRV and utramaratons, specifically. This is likely because ultrarunning has only recently emerging from the underground world to the mainstream universe, as has the general use of HRV trackers. Due to this, there is still a bit of a learning curve to overcome.

Even so, the world of biometrics is growing, and the running and ultrarunning world is beginning to embrace the technology to better understand how each individual responds to various factors.

So, how can biometrics help ultrarunners?

For starters, let’s talk about HRV.

Heart rate variability, simply put, is the amount of time between heart beats. And opposed to measuring heart rate (BPM), where a high heart rate indicates excursion and a low rate is indicative of an easier pace or even rest, HRV is much different. Generally speaking, the more variability, the better. A very low HRV is a sign of overtraining, stress, illness, etc., whereas a high HRV shows that your body is in good, resting condition, free of or nearly free from stressors, both mentally and physically.

A low HRV will tell you that you will need to back off of the training plan and perhaps add some lower miles or even rest. It may even show that there are some life stressors that need to be addressed. A High HRV, on the other hand, says that you are ready to run fast and/or go for the (ultra) distance.

In order to determine if your HRV is high or low, you will need to find your own baseline HRV level through the use of a fitness tracker with the available technology. Over the course of several days (preferably during a normal stress week) your wearable device will be used to determine what your average HRV is. This will help you to understand successive readings to find if you are experiencing high or low HRV.  

Active and Resting Heart Rate

While heart rate, both active and resting are not as relevant as we once thought, they are still an indicator of exertion and how are body has responded to the exercise, whereas tracking your HRV is not done in real time. 

Many ultra runners and group fitness instructor, Dana Anderson use heart rate tracking as an everyday, even all day tool. Anderson, who won the 2016 Javelina Jundred and 2017 Buffalo Run 100 says that she wears her heart rate monitor all day long. Biostrap allows you to monitor active heart rate through integrating with many 3rd-party chest straps. Being able to contextualize active heart rate with other insightful biometrics is a winning recipe for optimal training.

“I monitor my resting heart rate (RHR) to watch out for overtraining. If my RHR goes up a few beats  during training, I take an easy day, rest day, or focus on getting more sleep,” she said.

I review HR data after runs to make sure I achieved my objective, whether that be improved anaerobic threshold or working in my aerobic zone.

When I cross train, I watch my heart rate, it is much more variable for me while cross training. When I run, I pay attention to RPE (rate of perceived excretion) during and then look at numbers after. It took many years of practice and watching my heart rate while running, but now I’m very in-tune with my heart rate. I can usually guess within a beat or two of what the number is while I’m running.”

Determining Sleep Patterns

As important as your training regimen, if not more so is sleep. Sleep is a time when your body and mind rest and repair. In fact, during any given night, you will transition between many different stages of sleep — all of which play a critical role in getting your mind and body on track during the waking hours. 

Using a wearable tech device that tracks your sleep will let you know if you are achieving those all-important stages of sleep and if you are getting enough deep sleep and sleep in general. With that information at your disposal, you can make the appropriate adjustments so that you can rest and recover for optimum training and racing. 

Now, your gait

Wearable tech devices like Biostrap have the ability to track your gait and analyze it for future exercises. With the combination of a shoe pod and wrist band, you can obtain movement data as well as analyse your movement with that data.

This can help you determine if your gait has changed, where to make adjustments, etc. It really is a great tool.


Overall, using biometrics is a great way to understand your body when training and performing ultra distance races. It takes out the guesswork for you so that you can pay close attention to things your body needs. You may not feel stressed, but your HRV shows you are. This will help you take a closer look at your training and even life. You may be feeling tired during a pace that should be easy, and your active heart rate lets you know that you are pushing a little too hard at that moment.

You may think that you’re getting enough sleep, but find though your fitness tracker that you are not getting enough deep sleep. Perhaps you have purchased a new pair of running shoes that has altered your gait making you more prone to injury.

All of these things can be helpful when training for your first or even 10th ultra marathon, so that you can go the distance.

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