Sense heart rate is inaccurate

[Khitz3]

I purchased FITBIT SENSE. But it's heart rate is so innacurate that i am very disappointed with this smart watch. I purchased it in 21k but my other 4k watch shows better than that. Even i not exercise it's HR goes above 120+ sometime goes to level of cardio. Very Disappointing. Today i just left watch for sometime and wear it again watch shows that my active zone ka completed. HOW..???

Moderator Edit: Clarified subject and updated label

[DKS1959]

I could not be more disappointed with the Sense device.  It is not able to accurately count my heart rate during workouts, despite reaching out for customer support and taking every action recommended.  On the elliptical, for instance, it seems to cap my heart rate at no more than 111 and then start backing the rate down to the range of about 80BPM.  When I have worn my old device and the new one both, the old device measures the bpm up in the 130-140 range, while the Sense consistently shows a bpm under 90.

The device is literally of no use to me if it won't count heart rate while working out, since that also impacts things like Active Zone Minutes.  I can complete a 30-minute-sweat-filled-pulse-pounding elliptical workout out only to see ZERO Active Zone minutes registered.

Communicating with customer service has not been helpful, as they claim there is nothing wrong with the device.  Clearly they have marketed the Sense as a heart rate monitor for working out. If it isn't performing that function, how can there be nothing wrong with it?

This will be the last FItbit product that I ever purchase if we can't get this resolved.

[Guy_]

Hi @Khitz3  - look in the forum for other users with the same problems.

[Roxandfoxes]

I have the same issue.  I've had my Sense about a month.  It seemed to be working but the past week or so I've been exercising (usually HIIT, so high heart rate) and I'm below zones!!?  This is a joke considering if you look back on this forum and this issue has been apparent since launch.  If it carries on I'll be sending mine back and looking for an alternative brand to use.

[deiG]

Tons of users have had the same issue since day one, but Fitbit can't resolve it.

[deiG]

Fitbit has admitted that it's a known issue but can't resolve it.

[Khitz3]

Then what's the usage of wasting money on such high priced devices. Even MI
Band are better than this which almost cost 1/12 of it's cost. 🙂

[Guy_]

HI @deiG  - do you have a source for this admission from Fitbit that they can't resolve it?

What is known is there is an issue when moving but the heart rate is accurate when still for a moment, it has to be because it is medically certified for doing an ECG.

@Khitz3-  you are not just buying a watch but a whole infrastructure in the Fitbit App of measurements and history.

Though your point is sound; my cheap watch also is accurate, doesn't' breakdown, battery lasts and it will do blood pressure [albeit questionably] at a fraction of the cost.

What you do get with a Sense is Google Assistant [and except for Google Routines]  - this is brilliant.

Who knows they might actually fix the heart rate, floors and vibrations issues - though after so long it's not seeming likely.

[DKS1959]

It's so frustrating.  I guess I don't understand why they are permitted to continue to market it as a device that will monitor heart rate if it clearly doesn't do so.

[deiG]

@Guy_ , the official declaration is here:

https://community.fitbit.com/t5/Sense/Heart-rate-inaccurate-on-Fitbit-Sense/m-p/5029213#M39300

[SunsetRunner]

@Guy_ I'm not so sure that the HR sensor was involved in the certification of ECG as I think the heart rate during the ECG test is taken directly from the same ECG (and it makes sense as it is very easy with some digital signal processing measuring the time between peak to peak hence the frequency) and not from the HR sensor.

MY HR is very low (this night I recorded a lowest of 37) and, when some weeks ago I tested my wife's Sense, the ECG said it was not possible to provide a result due to low HR detected while the same Sense HR measured something like 85 (that was way far from my actual HR measured at the same time via finger oxymeter at 44).

[SunsetRunner]

@deiG the official declaration by @LizzyFitbit is, in my humble opinion, quite vague and lives the door open to some fix, however, considering that the issue is present since the launch of the watch and nothing has been done in one year and half, I feel the problem is hardware and nothing can be done.

[deiG]

@SunsetRunner , I believe the official declaration actually means it's a hardware issue and can't be fixed. They just express that in a euphemistic way. 

[FrankFrankF]

Very disappointed too. I use the Fitbit to monitor BPM during heart revalidation after a heart attack. I didn't understand why my BPM was so low, till I was monitored at there heart training center that coordinates my revalidation program. Because of the low rates I was exceeding my limits, therefore these errors are not without severe risks. The sense is a Fitbit's flagship and I was willing go pay fot it go rule out risks like this. I understand from other complaints that Fitbit has no solution (is that a fact?). In that case the watch is useless. 

[t.parker]

@FrankFrankF  let's take inaccurate Sense HR aside (this is known issue and personally, I don't wait for fix anymore, it's not coming) but word of advice - never rely on any wrist-worn HR sensor for medical purposes. And this includes any brand. Wrist is worst possible place to wear the sensor and there is a reason why every manufacturer discourages users from using it instead a proper medical device.

[Emmakuz]

Thank you for posting. I wish I would have seen this prior to my purchase. It is so off I started to wonder if it was my chest strap monitor that was being too generous with my caloric burn count. This watch is not as good as my old HR Fitbit. For what it is giving me I should’ve gone Apple Watch instead.

[eezeepee]

It's been plenty accurate for me in my 3 weeks of use. Definitely getting better heart rate readings than my Fossil Gen 5 Carlyle which seemed to be low. I think today I'm gonna test with my heart rate monitor chest strap my elliptical has and compare.

Update:

No need for me to test it. I replied with a very thorough heart rate test video.

[eezeepee]

https://youtu.be/qt7hBdddCrw 

Very thorough heart rate review which includes original software numbers and updates up to July 2021. There is a delay in the increase in heart rate and the accuracy at the highest rates is lower. Updates did improve in both areas though. It does depend on the type of the workout, for example weight lifting does worse than spinning however he said all wrist monitors have that issue.

[TommyIzzo]

@eezeepee I superset weights with 1.5 minutes between rounds. Weightlifting gives me the highest heart rate readings, while spinning will be all below zone.  

[TommyIzzo]

I like how @t.parker put it in another thread. Reviewers aren't paying for my product and don't determine whether it works for me or not.