Heart rate zones dropped

[mlr2]

I am recovering from Covid. A couple of weeks ago I took my most brisk walk since and it was quite exerting. The next day my heart rate zones according to fitbit dropped considerably. Have I hurt my cardio capacity? 

[RiekoC]

Hello @mlr2 

Based on some articles I've read, it seems some people recovering from Covid have various lingering issues.

It would probably be best to discuss your concerns/questions with your physician/healthcare professional. They can do an evaluation to determine if your reduction in your cardio capacity is temporary.

[mlr2]

Thank you - I have an appt with my cardiologist this week. I just hope she takes it seriously and doesn’t think it’s a Fitbit issue. It happened the very next day after my walk.

[Triletics]

@mlr2 unlikely caused by your condition. Depends on what Fitbit you use (you didn't say), Fitbit zones are based on your heart rate reserve which includes resting HR and max HR or on a percentage of maxHR. Your zones would drop in two cases. On modern Fitbits, your HRR shrunk and/or RHR dropped (so the FB zone would start earlier, did you notice any big change in your resting HR?). HRR would shrink only if your maxHR went down and that on Fitbit depends only on your age. On the older Fitbits which don't use HRR-based zones, your zones depend only on maxHR (hence, only on your age). It is unlikely to see a drop like that overnight for any other reason but a Fitbit issue (or what recently users noticed - by switching to a Google account with 1900 as the year of birth.

[RiekoC]

Hi @mlr2 

I encourage you to be your own advocate when you see your cardiologist this week. Potential heart issues are not to be taken lightly, as you well know. You want to be sure all is good for your own peace of mind, especially since you found your walk exerting.

That said, if you recently migrated your Fitbit account to your Google account, it might worth checking your birthday on your Google account. Users who migrated their accounts to Google discovered their birth year was default set to "1900", which impacted certain Fitbit features, including heart rate thresholds & zone minutes.

[mlr2]

I have noticed a change in my RHR over the last 2 months, generally only a couple of points at a time. I guess that’s why I hadn’t noticed so much. Also because my heart rate was around 59 a month before Covid when I was exercising a lot and I was getting in better shape. Of course now I’m not exercising at all except that day when the walk was actually logged as an exercise walk. I don’t know what’s considered a big drop. It has gone from about 66 to 58 since first of January. But there was no big drop the day after my heart zones dropped. It had been at 58 for at least a week before that. I have not migrated to Google so it’s not that. Go to the cardiologist tomorrow. Maybe get some answers there if she believes in Fitbit numbers I guess. Thanks so much for your reply!

[mlr2]

Thanks I definitely will. I haven’t migrated to Google yet so it’s not that. 

[RiekoC]

Hi @mlr2 

I hope your appointment goes well. Sending you tons of positive vibes.