HRV, low state for a long time

how do I reset?  I have a few options. When I choose factory settings, it says music and activities stay on the watch. If I want to delete activities, that is another option

Soft reset - Hold in light button until watch shuts down completely , then restart after say 20 secs. This often resolves issues, so do try that first.

If I reset, I generally delete data and reset settings "last option I think it is" , but it's a drastic step as its basically starting the watch from scratch, although fortunately most metrics come back from GC sync.

Do do a backup of device first as a safety step as mentioned.

I'll give it a go.

if the watch is working normally, a reset is not going to influence your metrics. Deleting or correcting activities will not either. For all the Firstbeat related metrics, what the watch sees, it will not forget until the data/related prediction fall off whatever time-window is used.

Whenever there is change in HR Max or LTHR, it is better to reset the zones (whatever system you use).As you saw, they don't update properly. 

To reset zones, on the watch, choose reset zones for all the default and sport zones you might have, select another base for the zones, reset again and then go back to your preferred system.

Your HR Max is the cornerstone of pretty much all the metrics on the watch. You need to wear a chest strap for all activities. Make sure you wet your strap, and monitor the HR data during warm-up because there is still a risk of bad skin contact.

A good DIY HR Max field test, if your doctor lets you, is to run your best 5k ever. Take the peak HR of that and add 5bpm.

After you change the HR Max, do a built LT Treshold Test. The combination of your HR Max data (HR and pace), rest HR and LTHR/ LT Pace are key for the HR/Pace/duration relationship the watch is modeling and using for the VO2 Max, race prediction, DSW targets, performance condition and stamina models.

Don't trust the LT auto-detection in particular if you do high intensity intervals shorter than ~20 mn each, unless you increase progressively the intensity during the workout..

Maintain a balanced training program so that the watch is exposed to a variety of efforts across a variety of durations. If you can, add some maximal efforts in there.

After a few weeks, the models will be realigned.

Thx Etupes25, MaxHR and LTHR and Zones are all  good. The reason for resetting now is a drop in HRV status, and no recovery for it, three months ago. Without a sensible explanation. It is my ultimate try to fix the weird readings. If the watch is not broken, it must be me who is broken

had to choose my watch face again, get the glances in the right place and start up wifi and spotify again. A bit annoying, but doable

How did you get a plot of such a long period of HRV data? In the Connect web page, I only have options for "Last 7 days" and "Last 4 Weeks".

NVM, I figured it out. It is not 100% intuitive, but easy to get to.

On the Connect web app, go to Reports > All Activities > Training Status. Then select 1 Year in the upper right. Historical HRV data is in the collections of graphs.

connect.garmin.com/.../last_year

Thank you.