Heart rate reading too low

[Aneesaanisa]

Hi I do a lot of HITT workouts and 5 I'm runs.  My heart rate on my surge doesn't seem to be picking up correct heart rate.  I wore a polar heart rate monitor on my arm and huge discrepancy. My heart rate on polar was far higher during exercise than my surge was showing.  Heart rate at rest is correct.  Why?

[RobertoME]

Hello @Aneesaanisa, good to see you one more time in the Fitbit Community! Since you mentioned the resting heart rate is looking correct, it might be possible your tracker is finding some difficulties to read your hear rate while you are doing high intensity exercises.

In occasions the tracker can have difficulty finding a signal, typically due to the tracker's fit. For example, wearing your band tightly may constrict blood flow in your wrist and affect the signal. Experimenting with how high you place the tracker on your wrist by moving the tracker up a couple inches can be helpful too during high-intensity exercises.

Hope this helps and let me know how it goes.