I'm a 55 year-old woman, fit but not extraordinarily so. I run 6 miles/day, and in 2021 my RHR was 49 average (it seems to have ticked up a couple of notches this month!).
When I run, however--nice, easy, 6-mile runs (at about an 11 minute mile), during which I'm not breathing hard, not working hard, and often chatting--my HR was peaking at about 210 (!) and averaging about 170/180. I never would have known this in a million years if it weren't for my fitbit, but a nearby gym's elliptical machine gave a similar reading the one time I used it (I wasn't paying close attention to this yet, so it may have been somewhat lower, I just noticed it was high). I made an appointment with a cardiologist, after mentioning this to my GP. This was true for at least 3 months (all I've gone back so far).
I had bloods done (fine) and a calcium scan (0%). I'm about to have a stress test too--the 3rd and last test she recommended before the only logical conclusion would be that it was just the odd way my body works.
AND NOW, even more oddly, the fitbit readings are totally normal--peaking at about 160/170 and averaging more like 135. That's consistent in the last 10 days.
I haven't updated my software, so I don't think the fitbit (Charge 5) itself has changed. Does anyone have any idea what could possibly have caused either the super-high readings, or the sudden change to normal readings? Is there an easy way (beyond hitting "get 10 more" a hundred times for my runs in the dashboard) I could go back a year or two, and see if those early readings were also super high?
Many thanks!
