Week 27: Resting heart rate and HRV by activity level and age
hi there 👋
I hope everything is well.
Today we look at resting heart rate, HRV, activity level and age, to highlight some key differences between these two ways to assess your heart rhythm.
In particular, what is the relationship between resting physiology, activity level, and age, and how does this differ for resting heart rate and HRV?
In this data, physical activity level can explain only 5% of the variance in HRV, while aging explains 14%, i.e. HRV tracks well with aging, over decades, but not much with physical activity level.
For heart rate, there is no influence of aging (0% of the explained variance), and 10% of the explained variance is due to physical activity level, i.e. heart rate tracks quite well with changes in physical activity behavior / cardiorespiratory fitness, as we know from the scientific literature as well.
In the graph above, I've transformed HRV to logarithmic units (times 2, this is similar to the score you see in HRV4Training) as HRV is not normally distributed. This way it is easier to see that HRV tracks a bit with physical activity level, but not much (and maybe not beyond what can be explained just by a reduced resting heart rate?).
This makes HRV a poor outcome metric, as even quite different physical activity levels, resulting in very different resting heart rates, might result in the same or very similar HRV, for people of a given age group.
Still, HRV does reduce quite clearly with age, and in ways that are not reflected in heart rate data, hence possibly providing valuable information on the "health" of the autonomic nervous system: there is something in there that is clearly not captured by resting heart rate alone.
Different metrics, different uses.
As looking at reductions in HRV over fifty years might not be the most practical way to go about it, I consider HRV useful mostly in the context of managing stressors on a day-to-day basis, as a marker of our response to such stressors*, and not as an outcome metric (with exceptions, of course).
*keep in mind that to use HRV this way, protocols matter, and data must be acquired at rest, far from stressors, otherwise you are not assessing your response
Podcast 🎙️ NoJetStress
The NoJetStress Podcast is a traveler wellbeing podcast for frequent business travelers covering health and peak performance on the road as well as to help business travelers maintain optimal health and avoid burnout no matter how much they travel. Christopher Babayode, a Corporate Travel Wellness Expert shares his insights on Traveler Wellness.
This is episode, Christopher discusses:
Meet Marco Altini: Founder of Heart Rate Variability Training the app and data scientist advisor for the Oura Ring.
What is HRV?
HRV as a Stress Indicator
Morning vs. Night Monitoring
Practical Applications: HRV isn't just for athletes; business travellers
HRV Training Techniques: Slow-paced breathing exercises and biofeedback
Importance of Recovery: Balancing action with adequate recovery is crucial
Individual Variability: Genetics, lifestyle, and stress levels influence HRV
Low-Hanging Fruit for Travellers
Recent articles and updates [June 2024]
Below is my personal newsletter including articles and updates from June 2024. Please feel free to comment below or in the articles should you have any questions, and I will follow up soon.
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HRV4Training Pro is the ultimate platform to help you analyze and interpret your physiological data, for individuals and teams.
You can find a guide here.
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In the app, Pro brings the normal values view, which can help contextualizing longer-term changes, as well as rMSSD on the homepage, see an example below:
See you next week!
Marco holds a PhD cum laude in applied machine learning, a M.Sc. cum laude in computer science engineering, and a M.Sc. cum laude in human movement sciences and high-performance coaching.
He has published more than 50 papers and patents at the intersection between physiology, health, technology, and human performance.
He is co-founder of HRV4Training, advisor at Oura, guest lecturer at VU Amsterdam, and editor for IEEE Pervasive Computing Magazine. He loves running.
Social:
Twitter: @altini_marco.
Personal Substack.
Thanks for this article. On the graph I see rMSSD is mentioned but isn't it the HRV measure? Even after having read on the topic and did measurement for 9 months I am still a bit not sure what is the "best" value to look at between HRV and rMSSD. Or perhaps it's the morning and I need another coffee to read this article ;-)