Charge 6 recorded heart rate data all last night, but won't calculate HRV?

[lakham1]

What it says in the title. Is there a way I can manually force it to calculate my HRV? I wore it all night and it recorded my heartrate throughout, but when I go to health trends to see my HRV, it says, "No data in the past 24 hours."

Moderator edit: clarified subject.

[ManuFitbit]

Hi @lakham1. Welcome to the community forums.

Thank you for taking the time to share the details regarding this difficulty with Charge 6.  

The Charge 6 needs to be able to get consistent heart rate readings during sleep for at least several days in order to establish HRV. I'd suggest you take a look at the following points:

• Wear your device for at least 1 full day (during the day and to sleep at night). Check your stats after you wake up in the morning. Note: skin temperature requires 3 nights of data.
• Make sure the back of your device is in contact with your skin. The band should be snug but not constricting. If you experience any discomfort, loosen the band, and if it persists give your wrist a break by taking it off.
• Most metrics require at least 3 hours of quality sleep. If you move a lot during your sleep or the sleep session is too short, you might not get a reading.

For more detailed information, see What should I know about health metrics in the Fitbit app? In case the HRV is being tracked but it's not being shown in the app, please try the following steps as well: 

1. Log out from the Fitbit app.
2. Clear Cache and Cookies for the Fitbit app on the phone's settings. 
3. Restart your phone. 
4. Log back in and check if you're able to see your information properly.