Fitbit Sense is not tracking heart rate accurately

[Dangerpony]

Just upgraded from Charge 5 to the Sense and ever since my workouts are all of a sudden under zone for almost the entire workout. Historically, I have tracked 45 minutes (at least) in Fat Burn zones with 10-15 min in cardio and maybe 5% under zone. Now I am tracking below zone for 85% of my workout. Nothing has changed with my efforts and my husband who still has the Charge 5 and we would track pretty much the same as me still has the same zone scores that I had previously. It is clearly a HUGE bug in the Sense product. When will this be resolved? It looks like the last comms on this was back in Jan. Will there be a software update soon fixing this? If not, I’m returning and going to find another more reliable product.

[Guy_]

Hi @Dangerpony - there is no news on whether this will ever be fixed. Given the time it has been a problem, it probably won't be fixed.

[Anmluvr]

Using bike mode yesterday the heart rate indicator was completely wrong showing a max heart rate of 215!  I would have been in cardiac arrest. I contacted Fitbit, was told to power it down then back on. Doubtful it will fix it. 

[MtnBuoy]

I am experiencing the same. See this string for other input  https://community.fitbit.com/t5/Sense/Inaccurate-heart-rate/m-p/4802807#M19534

[CraigHansen]

Be glad you don't have AFib (atrial fibrillation), because if you do, the Sense will display highly misleading heart rates, depending on how irregular your heart rhythm is. It's fairly easy to estimate heart rates from someone with a very regular heart beat, as once you have a good estimate of the rate, you know exactly where to look for the next beat, and can make minor adjustments to improve the estimate, while rejecting noise coming between beats. For someone with AFib, Fitbit's algorithm performs very poorly, and tends to miss beats like crazy.

Even the 30-second ECG does a poor job properly counting beats than the accuracy they claim. If Fitbit really cares, I could show them ECG traces with obvious AFib beats that their analysis reports as normal rhythm.

For myself, I recently had an ablation of the region around the pulmonary vein that has done a great job stopping the AFib, so now even Fitbit's lousy algorithm can measure my heartbeat.

[GDC9621]

Same issue here. Just did a static row for 20mins at 2.15min per 500mtrs consistent speed at 80% of the time my HR was showing as sub 100, except for about 3mins 2/3rds the way through when it jumped to 155. I have had 3 other model fitbits before this one I bought in Feb and none have ever had this issue, so Fitbit know how to make a product that works (not counting the battery issue with Ionic), so why can't they fix this issue, it is fundamental to the function of a fitness tracker, so you would think it would be a big issue for them. They should at least let potential customers know, as selling something with a known fault and not advising the customer, is reportable to consumer affairs. 

[SunsetRunner]

In August it will be 2 years since the Sense went on sale and if they haven't fixed it until today, they won't fix it at all.

[TommyIzzo]

@GDC9621 Sense and Versa 3 had a different heart rate technology which Fitbit thought was going to be more accurate. The fix probably isn't that easy. Maybe on the next products?

[Santoz]

I too am seeing the exact same issue, the heart rate is completely inaccurate, I even bought a second one and actually it was worse.....at the moment the heart rate of my kitchen counter according to my Fitbit Sense is 77....yes my kitchen counter....

[MtnBuoy]

I am returning mine within the 45 day return period.... I have had a Fitbit of various models for about 10 years I guess.  I don't know what tracker I am going to go with now but I have to act  before the window closes.  I am hoping Fitbit gets back to us and offers a corrected/updated model before I am out of the Fitbit arena for good.  Some other things with the Sense weren't  perfect but to me the heart rate is part of the core functionality - without it calories are off as are other tracked data.  It seems like the most basic testing would have told them this - maybe a provider changed something in the sensor that was supposed to be transparent and it went undetected.  I've seen it happen with other sensory and measurement electronics.

[Anmluvr]

I have exchanged multiple emails with Fitbit, still waiting on them to
exchange my Sense as it’s clearly malfunctioning!

[Santoz]

I went back to my charge 5, heart rate seems to be good but gps is complete **ahem**......I now have a Garmin 645 music, I have been wearing both Charge 5 and Garmin 645, there is just no caparison the Garmin just out performs and is by far dead on when it comes to accuracy. 

[Dangerpony]

I returned my Sense too and am back in the Charge 5. Not surprising, my workouts are back on track.