Blaze HR inaccuracy in workout mode

[AnnikaB89]

Recently I have seen a discrepancy in my heart rate when selecting 'workout' mode as opposed to it auto tracking when I am walking.

I walk the same route at the same speed every time. My watch is always in the same position. Usually, I select 'workout' mode from the point I leave my house to the point I return, therefore including my walk, my gym session, and my walk home all as 1 activity. When I do this, my HR during the walk is between 120-135 bpm. BUT, if I let the Fitbit Smart-Track my walk to the gym, my HR is only between 65-80 . I walk quite fast, but my resting HR is very low (40's). Why does the 'workout' mode detect my HR at a significantly higher rate when I am doing the same activity? 

I also tested it whilst I was walking. So I start the 'workout' mode and start walking. After about 15 minutes, when my HR is showing as say 130, I quickly end the 'workout' mode (but I still walk, don't stop and change nothing). A few seconds later, my HR disappears completely and then return within a few seconds, but displaying my HR say 80! Personally, I think the 'workout' mode is wrong because I typically struggle to get my HR that high even on the cross trainer. I should say, however, that it is very accurate once I am in the gym, it is literally just when I am walking, but using 'workout' mode.

Any thoughts as to why this is happening? My calorie counting is quite pedantic so I I don't like it!

Moderator edit: subject 

[AlejandraFitbit]

Welcome to the Community @AnnikaB89.

If you are having issues with your heart rate information while working out, I recommend taking a look at this post, where you will be able to see some things that might be affecting this reading and some tips to improve it. After these steps, test your Blaze.

Let me know the outcome.