Charge 6 heart rate differs from Inspire HR

[nanduu]

I went from an Inspire HR to a Charge 6 yesterday. The Charge 6 made me update immediately after turning it on. And the first thing I noticed is that my heartrates on my new Fitbit are quite a bit lower than on my old one. I was worried that the Charge 6 wasn't working right or that I was wearing it too tightly, but now I see some posts about the update here and I think that must be it then...? I used to get into fatburning zone all the time while doing everyday tasks, but now I don't get my heartrate anywhere near that. I'm so annoyed and I can see this being quite demotivating on the long run... How are you guys feeling about this result from the update? And is there some way to maybe hack this issue?

Moderator Edit: Clarified subject

[LZeeW]

Hello @nanduu and welcome to the Community.  It's very common for users to see differences in heart rate between devices.  The Inspire HR was released in 2019 and the Charge 6 was released in 2023.  The Charge 6 is advertised as giving more accurate heart rates during exercise.  Technology changes.

Based on your statement of getting fat burning minutes doing everyday tasks, I suspect your Inspire HR was overestimating your heart rate.  Fitbit uses CDC and WHO recommendations for physical activity.  Here is a link that has a lot of useful information: What Counts as Physical Activity for Adults?  I need to add that these recommendations no longer use fat burning, cardio and peak.  The terms are moderate and vigorous intensity activity.  Your Charge 6 is completely up to date in this regard.  Examples of moderate activity include brisk walking, riding a bike and doubles tennis.  When you do moderate activity, you should be able to speak the words to a song, but not sing the song.  You should be breathing hard and possibly breaking a sweat.

You ask for a hack, but I don't think there is one.  I think you were lulled into a false sense of accomplishment by an inaccurate heart rate.