Decreasing HRV after illness

I've got exactly the same situation, I'm guessing that your resting pulse is higher too like mine, I think this is taken account in the HRV readings as the higher your pulse the lower the HRV is. All i can say is take care of yourself and don't train until you feel your body is ready. Get well soon, it's been one month for me :(

Sorry to hear you have been unwell too. Weirdly my resting pulse is around the same as it was before (45-50). I'm never really sure how seriously to take the health stats on my watch but this seems like a real downward turn. It's also saying my training readiness is moderate though and I hate not doing any exercise. I think my watch is a little confused, as am I! 

No need to worry, the baseline should settle again in 3-4 weeks and then the readings will become normal.
I have had the same situation, was ill and couldnt do any workouts. When after 2 weeks I started workouts and run again, then my training status was "strained" but after 4 weeks all was normal again.

It is accurate and those readings are wildly sensitive.  ONE BEER shows up.  Yeah, its real and as you heal it should return to where it is supposed to be.

Great thankyou, in that case I'm going for a run! 

Thankyou, will take it easy but need to get out there for some proper exercise asap! 

I’m glad your health is improving.

I’ve been reading about my Fenix 6X after some recent issues Ike low HRV and STRAINED training status.

Wrist Heart Rate (HR) - This is used for tracking HR when Fenix 6 is worn on arm. HR is used in many algorithms that calculate things that rely on ACCURATE data to calculate stuff such as: Sleep, calories, HRV, VO2 Max, training load, intensity minutes, training effect, respiration rate, pulse ox, respiration rate, sleep score (you get the idea).

Garmin advises that HR data is NOT ACCURATE  [source: Connect Help]:

• ‘While our wrist HR monitor technology is state of the art, there are inherent limitations with the technology that may cause some of the heart rate readings to be inaccurate under certain circumstances.
• ‘The HR monitor data is not intended to be used for medical purposes, nor is it intended to diagnose, treat, cure or prevent any disease or condition.’

HRV is a feature that takes inaccurate wrist HR data then somehow provides a precise reading of time between heartbeats and creates a score. The inaccurate wrist HR is used to identify time between beats like 825 ms and the tiny graph appears to have 10 data points per hour.

The HRV score influences your Training Status causing it to give constant useless ratings like ‘Strained’. You can’t switch it off and Garmin Help doesn’t provide details of ‘normal’ HRV ranges by age.

I recently had covid, and here is a study that looks into the long term effects on HRV.

www.ncbi.nlm.nih.gov/.../

Well...... I had Covid in the first week of August 2021. At the time the Fenix 6 series did not have HRV, but I am an active runner (distances up to half-marathons on a regular basis) and DO have over a decade of performance data from various Garmin watches and had at that point quite a continual collection of overnight (e.g. "at rest") heart rate and similar.  I got hammered pretty good, and while there was a significant short-term impact on VO2Max and lactate threshold (along with absolute performance) it was completely recovered within LESS time than the influenza hit I took the first week of January 2020 (and which I know was not Covid -- I thought it might be when it hit and thus sourced antibody tests -- which were negative all the way until I got it in 2021, and they have rang positive since.)

It is now close to 2-1//2 years later and there has been no long-term impacts on my athletic performance at all. Where I was prior to infection is basically where I am today, which when you get down to it I should see some small deterioration just because I'm now 60 and you'd expect a small amount of natural deterioration over time as you age.

I am not, however, jabbed -- at all -- and I've not had the virus again either, and further as of a few months ago (I have at this point run out of antibody tests) I still rang positive for IgG more than two years after infection.  There may or may not be actionable information contained in all that (after all I'm a trial of one) but it definitely does not conform with that study, and a quick read does not show separation on jab status.  Most elite athletes, especially those who travel internationally and thus were subject to requirements to take it in order to be able to compete over the last three years, almost-certainly did take the shots.

One thing I will note - I now have a Fenix 7 Pro and the HRV readings are different.  This I've seen with other maker's devices too and thus you have to be very careful trying to compare across devices with potentially-different hardware on a single person (probably will get different results that confound analysis) and certainly across people (e.g. how tight do you wear it, what band do you use, what's your skin pigmentation and/or hair, etc. where it is worn and similar) since these are not medical devices and as a consumer product individual variability in their use is significant as well.  As such I think you can reasonably interpret changes you see for you, on your device, provided the device does not change (if it does you'll have to establish a new baseline) but not across individuals as the confounders that interfere with repeatable and generalizable results across persons and devices are simply too great.