Sense 2 heartrate tracking incorrect during treadmill workout

[Mbyk]

My sense 2 seems to track everthing accurately during walks and other workouts, but when i use the "treamill" setting, it says my heartrate stays around 80 BPM, though the heartrate sensor on the treadmill says 180 BPM. I've tried repositioning the watch on my wrist, resetting it, turning it off and on again, and am at a loss. 

[Guy_]

HI @Mbyk - it depends on the person and the movement but generally the Sense 2 can be quite unreliable during movement. Fortunately it works better at rest, for Sleep etc. Anything that depends on HR otherwise may be quite inaccurate.

[DainKistner]

Similar problem here, though mine does not seem very accurate during any workout.  I am planning on returning mine and replacing it with the charge 5, as the consensus seems to be that is the more reliable activity tracker.

[rajat1048]

Fitbits are worst for tracking Heart rates. A recent instance before i decided to sell this one off was one of my relative was suffering from tachycardia so i offered my sense 2 to measure the Heart rate and sense 2 just showed 78 bpm as a resting HR. To my surprise i asked her to put her fingers inside a reliable pulse oxymeter. The oxymeter showed her HR to be 98 bpm. Then i asked her to wear my old apple watch 3 on the same arm she wore the sense 2. The apple watch provided the most accurate result 99bpm. 

I had problems with sense 2 showing inaccurate HR during HIIT and other strength trainings but i was sure it might track the resting HR accurately. But after the above mentioned incident i lost my trust completely and sold this thing in used items marketplace. If you are not satisfied please return this so called smart watch ASAP and look out for better alternatives.