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.
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.