My Fitbit Charge 2 is clearly tracking heart rate incorrectly and is wildly off when I’m cycling uphill. It reports a heart rate of below 80 bpm for a good part of the uphill portion that’s the most strenuous portion of the ride. I know I’m exerting a lot of energy as I’m breathing heavily and it’s a challenge breathing through the nose alone (without using my mouth) during this strenuous stretch. It reports my average heart rate for the ride as 130 bpm and except for that steep uphill 20-25 minute portion, it’s HR readings seem as expected and between 125-160. Is the Charge not designed to measure HR accurately while cycling outdoors? Why does this problem consistently happen only during the uphill stretch?
This screenshot clearly shows the lowest heart rate regime overlapping with the steepest uphill gradient:
https://www.dropbox.com/s/w25orkar7kvqar9/Low-uphill-hr.jpg?dl=0
