Fitbit HR data different in app

[Orm-Irian]

Hi, I'm using an app called Cardiogram to track my HR (I have POTS), and the data that it captures from my Fitbit shows considerably higher highs than the graphs in the Fitbit app itself - if I was only using the Fitbit app, I wouldn't know how crazy high it's getting. Any idea why that is? I can tell thé Cardiogram data is correct because it matches the HR display on the Fitbit itself - so it looks like the Fitbit app is "smoothing out" the data?

[LZeeW · Accepted solution]

@Orm-Irian   Your Fitbit tracks your heart rate data beat-to-beat.  The heart rate graph on the Fitbit app shows a heart rate that is averaged over five minutes.  I don't use the Cardiogram app, but suspect that it uses a shorter interval.  This is why the Fitbit heart rate graph appears smoothed out.

[Orm-Irian]

Thanks, that makes sense - the Cardiogram app seems happy to take as dense a data stream as you can hand it (when you run the Apple Watch hr thing in constant mode it's every 10s, and this seems even denser) so no wonder the Fitbit app is losing the spikes - though it doesn't even show them in exercise mode, so it's good that I have the other app for detail.