My measured RMRastvyear was 1470 and since before that time my Garmin has had my resting cals at 1450 (pretty accurate!), but suddenly 2 days ago this fell to 1444. My app isn't connected to my weight scale or MFP. I hadn't ever set activity level so it was at 0. Is this due to age that it decreased? Over time will my resting calories go down like this?