What do the flash surrounding the HR mean on Versa 4?

[Joeqwe]

Does anyone know what the flash asterisks surrounding the heart monitor mean?  Thx

Moderator Edit: Clarified subject

[JohnnyRow]

I expect that indicates you are in one of the heart rate zones, not sure which one, probably changes depending on fat burn or aerobic.

[MarreFitbit · Accepted solution]

Hi there, @Joeqwe. Welcome to the Community Forums. 

When your heart beats, your capillaries expand and contract based on blood volume changes. To determine your heart rate, the optical heart-rate sensor in your Fitbit device flashes its green LEDs many times per second and uses light-sensitive photodiodes to detect these volume changes in the capillaries above your wrist. Then your device calculates how many times your heart beats per minute (bpm).

We use green LEDS because they maximize the signal detected from the capillaries near the surface of the skin. The optical heart-rate sensor also uses infrared light to determine when the device is on your wrist to improve the accuracy of your heart-rate data. For more information, see How do I track heart rate with my Fitbit device? 

As @JohnnyRow mentioned, your watch notifies you a few moments after you enter a different heart-rate zone. The number of times your device buzzes indicates which zone you’re in:

Number of Buzzes	Heart-Rate Zone
1 buzz	Fat burn zone
2 buzzes	Cardio zone
3 buzzes	Peak zone

For more details, see What are Active Zone Minutes or active minutes on my Fitbit device? 

[LZeeW]

@Joeqwe   I read your question several times and I'm not sure what your asking?. You wrote heart monitor.  Are you asking about the Versa 4 device or one of the screens?