Versa heart rate tracking accuracy concern

[SunsetRunner]

Please help! Experiencing a drastic drop in heart rate accuracy after the latest OS update for Versa. I have a Polar H10 chest strap for comparison and the Versa is now under counting by 10-30 bpm depending on intensity when doing bootcamp style HIIT sessions. I've gone through soft reset (with the left and bottom right buttons), shutdown and restart while disabling then enabling the heat rate function. I really don't want to do a factory reset yet if it can be avoided. Any tips?  

Moderator Edit: Clarified subject

[RicardoFitbit]

Hi @SunsetRunner, it's nice to see you again participating here in the Community Forums.

Thanks for bringing this to our attention and for trying some troubleshooting steps before posting over here. Heart-rate tracking can be affected by several factors including air temperature and device location on your arm. Also, keep in mind that we do not recommend to compare the data tracked by your Fitbit with other tracking-devices because they may use different algorithms to track data. For more information about this, please check our help articles:

• How do I track heart rate with my Fitbit device?
• What factors can affect my heart-rate reading on my Fitbit device?

However, if your heart-rate tracker seems inaccurate after taking the recommendations into account, please reply with answers to the following questions so I can further investigate:

1. What were you doing when you noticed the problem? If you were exercising, specifically what types of exercise?
2. Were you wearing the Fitbit device particularly tight or loose?
3. What was the position of the Fitbit device on your wrist? 

I'll be waiting for your reply if further assistance is needed.

[SunsetRunner]

Hi Ricardo,

I usually only rely on my Versa the past year as it isn't comfortable wearing 2 monitors but lately added the Polar H10 to check stats as I suspected the Fitbit was off by a lot (it was). Before that the differences were acceptable to me, now Versa's way too low. Here are the answers to your question for clarification:

1. I was doing high intensity style HIIT training using weights with a lot of compound movements. For example, weighted Romanian deadlift to bicep curl and overhead shoulder press along with 30 seconds cardio acceleration movements (squat jumps) and 10-15 seconds rest between each circuit for 3 sets. Polar H10 recorded 176 bpm peak, Versa only 148 bpm. I've done this circuit before the latest update with better tracking so it's not the exercises itself, I think.

2-3. Versa is worn snug but not too tight to constrict blood flow and a little higher than wrist bone as advised to prevent loss of contact from when wrists may be bent. I've worn it this way before with better accuracy. 

Last week, before this happened, the screen used to freeze a lot when I pressed the exercise shortcuts set on the left button. I found there was an OS update and did so this week, that's when I noticed a huge difference between in heart rate tracking of the same workouts between this week and last week.