A few weeks ago, Garmin released their new HRV measurement tool for the Fenix/Epix lines. It measures your HRV during sleep.
I started looking at my HRV levels since, and to my surprise, after a few days, I started having lower levels than usual.
Here’s a picture of it
My HRV was lower, my RHR was higher, and my sleep and my training readiness were extremely low. And all these changed before having any symptoms.
I then did a test, and I was positive for COVID.
It seems that it gives a very good indication on infections/diseases.
(I wrote a full article on this here)
I replied in the comments section of your article, confirming that I’ve seen the same thing in my own HRV data.
thanks! meanwhile, i’ve been checking all my sleep data during covid, and it seems that my REM levels are practically zero
It’s a very interesting phenomenon. The capabilities of HRV in a predictive capacity for an acute inflammatory response secondary to illness is fickle and fascinating.
If you are interested - here is a study that reflects similar findings:
As for the sleep, I believe the cytokines (mainly interleukins) released by our body in response to infection typically lead to increase in deep sleep (slow wave sleep) and decrease REM/Wakefulness.
Thanks a lot for sharing your experience in the blog.
Substantial decreases in HRV preceded elevations in CRP in the ensuing 72 hours with a 90.9% positive predictive value
Incredible! thanks for sharing
My sleep tracker thinks that I’m no longer getting any deep sleep (while sick), but I think that’s just because it overemphasizes HR to determine deep sleep, and my sleeping HR is high (mid-70’s vs. typically low 50’s) which screws up its algorithm.
Also, my breathing rate from typical 14/min to 17.5/min while sick.
Looking at the history, my avg sleeping HR and breaths per minute were noticeably higher about 1 day before I had noticeable symptoms. My HRV was noticeably lower about 12 hours before symptoms.
Hi. There is great study from Snyder Labs which reveal heart rate pattern pre- and during covid. Since we know that when HR goes up (marker of disease onset) HRV goes down - HRV may help in same way to predict / diagnose diseases. It’s not specific to COVID, but to many diseases.
Recently i did cluster analysis on my 667 oura ring nights and found clear “sick night” (red) pattern (HRV ruins) and clear “restorative night” (green) pattern when HRV goes up.
It seems HRV is a pretty good biomarker to distinct disease / healthy statuses.