Resting Calorie Totals Suddenly Erratic From Day to Day

I've had my Fenix 6 for a few years now. Currently my daily total of resting calories for a long time has been 1401. Suddenly this week or so it has changed daily- and no I am not taking the watch off to charge the battery on these days. Why is this suddenly happening? I have not updated my weight and my RHR has remained within the same range as always.

For example:

9/8-9/10 it was 1401 (my usual resting calorie total)

9/11 it was 1482

9/12 it was 1459

9/13 it was 1342

9/14 it was 1576

9/15 it was 1634

9/16 it was 1167

9/17 it was back to 1401

9/18 it was 1751

9/19 it was 1146

0 trux 2 months ago

Could you post a screenshot of the page https://connect.garmin.com/modern/report/41/wellness/last_four_weeks ?

And could you double check at https://connect.garmin.com/modern/weight/2024-09-20/1 that the weight really did not change?

0 4040885 2 months ago in reply to trux

Weight is still the same in settings. Screen shot added to original post. I'm trying to remember when the last update took place for my watch. I can't remember but I think it was in the past month...

0 trux 2 months ago in reply to 4040885

4040885 said:
Weight is still the same in settings.

Please check it at https://connect.garmin.com/modern/weight/2024-09-21/1, perhaps it differs from the settings.

Apart of the gender, age, and height, it is only the weight that influences the Resting Calories. At older watches it could be also the Activity Class, but I am not even sure whether it has any impact on the Resting Calories. In any way Fenix 6 is not listed among devices using the Activity Class for any calculations at What Is the Activity Class Measurement in Garmin Connect? | Garmin Customer Support

So practically I can barely imagine anything else than the weight changing your Resting Calories.

Perhaps another possibility could be if you are a frequent traveller, and changing the time zones frequently. It would result in some days longer than others, and the RMR would be proportionally higher for such days. When not travelling, there could be a problem with the time or time zone settings on the watch, or on the phone.

0 4040885 2 months ago in reply to trux

I have noticed a couple of instances where my watch time was off versus my phone's time and had to sync using GPS or manually on the watch however I have not had to do that in the past few days- haven't noticed any issues yet yesterday's resting calories were 1109 and the day before it was 1692. My weight is still the same as it has been when I last updated it in the settings in June or July.

0 trux 2 months ago in reply to 4040885

4040885 said:
My weight is still the same as it has been when I last updated it in the settings in June or July.

Did you really verify it on the graph, and assured you that Garmin Connect logged the same weight on all those days?

4040885 said:
I have noticed a couple of instances where my watch time was off versus my phone's time and had to sync using GPS

I can easily imagine that it could be the reason for the irregularities in RMR. If the watch is unable to keep the accurate time, I recommend syncing the time with GPS frequently (several times per day). Normally, I would suggest contacting the Support, and have the watch replaced, in such case, but seeing you have the Fenix 6, it is unlikely it is still under warranty.