Unlocking the secrets of HRV - a holistic approach to health and invisible illness
By Tessa Nielsen (Specialised Health), and Dr Marissa Kelaher (Your Lifestyle Medics)
In the ever-evolving landscape of health and wellness, the term "biometrics'' has been popping up more and more.
In fact, wearable technology is projected to be the leading fitness trend in 2024 according to the American College of Sports Medicine (ACSM)!
Wearable devices, (often in the form of fitness watches, chest straps, or even rings), capture data that can provide valuable insight into our health and function.
From maximum heart rate, total activity levels to sleep quality, wearables have been used extensively in fitness and sports for years, and in more recent times have made their way into the health and rehab space.
Yet understanding how they work (and how to use them in day-to-day life) can be a complex topic that isn’t always easy to understand - so we thought it was about time for a deep dive!
Let’s find out more about our favourite biometrics, and how they can be a vital tool to help optimise our health and wellbeing.
Heart Rate Variability (HRV)
While many wearables focus on sleep data, heart rate, or steps (all of which are of value in themselves); a lesser known biometric, and one we find incredibly useful, is Heart Rate Variability (HRV).
This metric has garnered significant attention in research over recent years, and is increasingly being used for a wide range of conditions - from chronic fatigue and long covid, to autoimmune disease and migraines, and even heart health and mental health.
So what is HRV anyway?
HRV is, in essence, a measurement of the variation in time between each heartbeat.
And while there may not seem like an obvious connection, it’s a powerful indicator of how our autonomic nervous system's (ANS) is working (1,2), which plays a key role in various illnesses (3,4).
To understand HRV, we need to take a quick dive into physiology, and the science of how our nervous system works.
Our ANS is made up of two branches—sympathetic and parasympathetic — also known as our fight or flight response, and rest and digest mode.
When our nervous system is functioning well, we maintain a delicate balance between these two branches, switching back and forth between them in response to life’s stressors. Sleep, exercise, stress, illness, and even diet impact on our nervous system, and we need both responses to function well in day to day life!
However when our autonomic nervous system goes out of balance, health issues can arise - and our HRV changes accordingly, getting ‘stuck’ more in one mode than the other, in a process also known as dysautonomia.
And research shows that dysautonomia in different forms is strongly linked to most chronic diseases - and can have a significant impact on our quality of life - even if we don't have obvious symptoms.
While on the other hand, improving autonomic function can potentially alter the progress of disease and help reduce symptoms, as well as improving our overall health.
This may seems like an abstract concept, and in the past has been difficult to measure outside of research situations. But the advent of home wearables is changing this, and studies now show that measuring our own HRV can provide an accurate indicator of this balance - meaning that by looking at HRV data, we can see how well our nervous system is functioning in our day to day lives!
This also means that by gathering consistent HRV data, we can discover whether someone has either parasympathetic or sympathetic dominance - ie are they swinging heavily toward or getting “stuck” in one mode or the other. (1,2)
Using this data, we can then start to adjust our day to day habits and life, to move our nervous system (and health) back into a state of better balance.
Biometrics in the World of "Invisible Illness"
Given the above information, it might come as no surprise that biometrics can be a highly useful tool in helping manage a variety of different health conditions.
As exercise physiologists, we use them in a range of contexts, but one where we see their impact the most, is in the space of "invisible illness."
Invisible illness is a term that encompasses conditions or disorders with largely invisible symptoms, such as chronic fatigue, long-COVID, mental health conditions and POTS.
These conditions affect a large number of people, and pose unique challenges due to their internal nature and complex symptoms, as well as their significant impact on quality of life - as anyone with living with long covid or chronic fatigue will know.
Biometrics can play a vital role in helping people with these conditions, as they give us real objective tangible information, to help us to tackle symptoms that are often highly subjective (ie hard to measure externally, even when severe), variable and fluctuating.
They also provide hope in an area where there is currently a huge lack of individualised rehabilitation programs or treatment options - and best of all can be done anywhere, by anyone!
In truth, they are one of THE most valuable tools we find helpful in supporting people living with chronic illness, so lets explore how you can start using them too!
In practice, a basic program utilising HRV looks like this:
Biometrics also empower conversations that allow us and our clients to gain more insights into their body and symptoms, to create a shared individualalised health plan.
Some examples of biometrics in use and the conversations they invoke might include:
Activity data to look at overall movement levels and trends;
“It looks like you did a lot of activity on Tuesday, and were forced to rest for 2-days after.
We call that booming and busting, let's look at levelling out your activity in coming weeks - you might even find that you can do more if we can get this more consistent”
Sleep quality and quantity to assess its impact on symptoms;
“Your sleep scores have really improved over the last 2- weeks, do you think it could be to do with the mindfulness we’ve implemented after work?”
Heart rate to see how the cardiovascular system is functioning
“You say you feel exhausted after small tasks like the dishes, but looking at your heart rate of 162bpm, these tasks aren't actually small at all for your body at the moment. We can look to improve this in coming weeks”
HRV to see how the body is handling all of the above, as well as other more invisible stressors;
“That presentation at work definitely took a toll on the body, but that's OK, lets include some parasympathetic recovery today, and think of how we can adjust the way you do this in future”
One of the most crucial aspects of HRV is that it's not only sensitive to physical exertion, it is also sensitive to non physical stressors (such as lack of sleep, emotional stress, mental overload and more).
And in a society that praises being busy, and frowns on rest as ‘weakness’, it can be highly validating and empowering to see the effect of these on our nervous system, and the very real impacts they can have.
This also opens up discussions on the impact of chronic stress on our health - after all, it’s been called the epidemic of the 21st century, and is thought to account for up to 80% of visits to GPs!
Research shows that HRV responds very accurately to psychological stress, cognitive fatigue, anxiety and even negative social interactions/experiences, so we can build all of this into the “load” as you would with any physical activity program (5,6,7,8).
Our mind and body truly are connected, meaning any holistic wellbeing plan MUST include all the areas that impact our health to be effective.
Imagine you are someone who has been battling with the frustrations of invisible illness.
The ups and downs, the reliance on constantly “checking-in” with your own symptoms, trying to identify and remember patterns. . . biometrics provide relief, validation and a sense of control.
They can take away some of the “invisible” in invisible illness, providing a path forward.
Where to start?
Getting started with using biometrics, specifically Heart Rate Variability (HRV) might feel a bit overwhelming. But don't worry!
Here's a straightforward step-by-step guide to kick off your journey. All you need is a Polar H10 strap, your smartphone, and just 90 seconds of quiet time each morning.
App Setup: Download the "Elite HRV" app on your smartphone.
Connect Your Device: Sync your Polar H10 heart rate strap with the app.
Daily Check-In: Follow these steps for your daily HRV check:
Find a calm spot within 10 minutes of waking up, keeping it consistent each day
Open the "Elite HRV" app
Select "Morning Readiness"
Opt for the 90-second reading while sitting
Start the reading and sit quietly, following any on-screen instructions
A quick tip: It's a good idea to gather 2 weeks of data before diving into any deeper analysis.
The app itself will provide you with some great info based on your readings. However, alongside your daily HRV checks, keep a simple diary of your daily activities. After two weeks of data, look for patterns.
Are there trends or noticeable ups and downs?
Do you tend to swing toward a sympathetic or parasympathetic dominance?
Do your poorer readings correlate with certain activities/loads?
Also, as you try out other strategies to improve your health, like changing your diet, meditating, or exercising, keep an eye on your HRV for extra feedback on whether they are having an impact.
Over time, we are basically aiming for two things:
More “balanced” readings: Strive for HRV readings that don't swing wildly from day to day.
Gradual Score Increase: Look for a slow increase in your average HRV score
These simple signs tell you that you're on the right track to improved nervous system function. So, enjoy the process, watch for patterns, and let us know how you get on!
And if you know someone who may benefit from this info (or would be interested in reading it), we'd love you to share it with them. Our vision is to empower as many people as we can to regain optimal health and well-being, and every part counts ♥️
Author: Tessa Nielsen
References:
Marques, K. C., Silva, C. M., Da Silva Trindade, S., De Souza Santos, M. C., Rocha, R. B., Da Costa Vasconcelos, P. F., Quaresma, J. a. S., & Falcão, L. M. (2022). Reduction of Cardiac Autonomic Modulation and Increased Sympathetic Activity by Heart Rate Variability in Patients With Long COVID. Frontiers in Cardiovascular Medicine, 9. https://doi.org/10.3389/fcvm.2022.862001
Shih, C., Chou, P., Chen, J., Chou, T., Lai, J., Lu, C., & Huang, T. (2023). Cancer-related fatigue classification based on heart rate variability signals from wearables. Family Medicine and Primary Care, 10.
Zalewski, P., Słomko, J., & Zawadka‐Kunikowska, M. (n.d.). Autonomic dysfunction and chronic disease. British Medical Bulletin, 128(1), 61–74. https://doi.org/10.1093/bmb/ldy036
Słomko, J., Estévez‐López, F., Kujawski, S., Zawadka‐Kunikowska, M., Tafil-Klawe, M., Klawe, J. J., Morten, K., Szrajda, J., Murovska, M., Newton, J. L., & Zalewski, P. (2020). Autonomic Phenotypes in Chronic Fatigue Syndrome (CFS) Are Associated with Illness Severity: A Cluster Analysis. Journal of Clinical Medicine, 9(8), 2531. https://doi.org/10.3390/jcm9082531Escorihuela, R. M., Capdevila, L., Castro, J. R.,
Zaragozá, M. C., Maurel, S., Alegre, J., & Castro-Marrero, J. (2020). Reduced heart rate variability predicts fatigue severity in individuals with chronic fatigue syndrome/myalgic encephalomyelitis. Journal of Translational Medicine, 18(1). https://doi.org/10.1186/s12967-019-02184-z
Kim, Hye-Geum, et al. "Stress and heart rate variability: a meta-analysis and review of the literature." Psychiatry investigation 15.3 (2018): 235.
Hjortskov, Nis, et al. "The effect of mental stress on heart rate variability and blood pressure during computer work." European journal of applied physiology 92.1 (2004): 84-89.
Lischke, A., Jacksteit, R., Mau-Moeller, A., Pahnke, R., Hamm, A. O., & Weippert, M. (2018). Heart rate variability is associated with psychosocial stress in distinct social domains. Journal of Psychosomatic Research, 106, 56–61. https://doi.org/10.1016/j.jpsychores.2018.01.005