The big picture

7 years of heart rate variability (HRV) data

I often share snippets of a few weeks to a few months of my heart rate variability (HRV) in response to various stressors.

In this blog, I want to zoom out over the past seven years and look at the big picture. A lot happens over such a long timeframe.

In terms of health, I crashed badly in mid-2021, almost without noticing, despite a very clear downward trend in HRV that lasted for years.

One night, almost out of the blue, my heart started beating erratically, and it didn't stop doing so for weeks. It was a big health scare, leading to behavioral and lifestyle changes that slowly would once again change dramatically the picture, this time for the better.

Before putting this data together, I had some expectations. I thought I'd see a big change in my HRV in mid-2022 when I lost some weight and started getting fitter and fitter. And yet, the change in this past year is meaningful but quite a bit smaller than the one happening in the previous year, when chronic stress was driving the major changes.

Chronic stress is hard to see, hard to quantify, and therefore hard to evaluate in its impact on our lives and health.

In terms of actual changes, initially, I tried to modify the "easily controllable". For example, I stopped drinking alcohol (which is often associated with erratic heartbeats) and also coffee (here the evidence isn't as strong, with studies showing even protective effects, but as we know there is large individual variability, and I felt like it was a potential trigger for me). I didn't make changes in training despite having doubts about its impact too.

Other changes I made weren't as immediate or as easily implementable. I have been struggling a bit with "environmental factors" where I live (lack of nature, long gray winters, etc.) - this might be trivial for some, but the impact on my mental health was quite large, and I would often get mildly depressed. Eventually, I was fortunate to have the flexibility to make changes on this, moving to places where I wouldn't experience the same issues for part of the year. Mentally I feel a dramatic difference, and I suspect this is also showing in the data, even though it may be more of a chronic effect.

Over the years I have also changed the way I look at the data, and I try not to worry about it, even when there are long-lasting suppressions. I try to think about it as something to be aware of so that I can prioritize my physical and mental health, but without getting into a negative loop (e.g. negative data influencing us negatively even more). It is fine for things not to always be great. Not sure I expressed this well, but I think this is a common issue and over time we should try to get to a healthier relationship with data and tracking, which I think I do have now. Feedback and awareness can be key for behavioral change or simply to gain a deeper understanding of ourselves and our environments if we strike the right balance.

It is very fascinating to me how these changes are captured over a long timeframe by simple morning measurements of resting physiology (my protocol here was always to use HRV4Training and the phone camera first thing in the morning). Little data can go a long way if we use validated tools and capture it according to best practices.

Looking at the big picture makes me think more about how we normally engage with data on a daily basis. When tracking these parameters (HRV or other), we probably tend to be overly reactive to small or short-term changes, and less engaged or aware of long-term ones that slowly creep in, eventually leading to negative health (or performance) outcomes. I wonder also if we give too much weight to our actions and to the (possible) changes that result from those (e.g. starting to meditate or exercise), while downplaying inaction (e.g. letting chronic work stress build up over years).

The more I think about these issues the more questions I have.

Let's keep learning.

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.

• Strava.

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