Charge 3 isn't tracking heart rate zones accurately

[yogaon]

does anyone know why my Fitbit charge 3 says I've got 17hr 26 min fat burn, and 44 minutes cardio when i haven't done any exercise at all, thankyou

Moderator edit: subject for clarity/format

[WilsonFitbit]

Hello @yogaon. Welcome to the community forums! 

Thank you for the detailed information. At this time, I'd like to let you know that your Charge 3 should show you're in the fat burn zone if you’re likely in a moderate activity such as a brisk walk. Your heart rate and breathing might be elevated, but you can still carry on a conversation. In the cardio zone, you’re likely doing a vigorous activity such as running or spinning.

If you haven't done any of these activities or a similar workout, I'd recommend performing a restart and long restart to your Charge 3 by following the instructions below: 

1. Connect the device to the charging cable. 
2. While the device is plugged into the charging cable, press and hold the button down for 15 seconds. 
3. The device turns on and shows a battery icon. Two vibrations occur: first a short vibration, then a medium vibration. 
4. The device turns off.
5. The device turns on and shows a progress bar and short vibrations occur. The progress bar completes. Note: A total of 7 short vibrations occur. 
6. Remove the device from the charging cable. The device shuts down.
7. Important: Plug the device into the charging cable again.

In addition, I'd like to let you know that several factors can affect your heart rate: stress, alcohol or caffeine intake, or fever usually raise it, while regular exercise or meditation can lower it. Air temperature and certain medications can also affect. For more information, I'd recommend visiting this help article: What factors can affect my heart-rate reading on my Fitbit device?

Hope this helps.