Heart rate inaccurate on Fitbit Sense

[Cameronoates]

Hey 

is anyone else experiencing huge heart rate inaccuracy during exercise with the sense? 

During exercise with the sense it won’t ever get above 120bpm for me 

but if I use my charge 4 during the EXACT same exercise my heart rate is between 145-170bpm in the cardio zone 

It’s extremely disappointing and I don’t want to have to switch to my charge 4 everytime I exercise to ensure accurate heart rate 

defeats the purpose of having the sense 

seriously one of the most frustrating experiences I have ever had.

Moderator Edit: Clarified subject

[Tdif]

So weird I also am having strange readings apparently today my heart rate went up to 163 for a few min but I was not doing anything I would have felt that I think for the money we pay this should not have so many problems .. I may just go back to the Apple Watch honestly this is crazy and can put ppl in a panic if they don’t know their heart situation… not acceptable 

[t.parker]

Today, I revived my Sense (I haven't been using it for a couple of weeks), updated and took it for a half-marathon race. Nothing really changed since my previous tests when it comes to HR.

Polar H10 (chest strap):

Polar OH1 (armband, optical HR, worn on the forearm near elbow):

Now PolarH10 and OH1. Despite totally different technologies (first uses electrodes like ECG, the second is optical just like Fitbit watches), the results are very very close:

 and then Sense comes to the party (blue graph):

Not that I hoped anything would be better...

[Irish57]

I purchased Sense for that reason, not working out to well honestly! 

[SunsetRunner]

Great post, @t.parker .

Thank you.

[JackDrake]

It's similar to what the "quantified scientist" (youtube) figured out and similar to my comparision yesterday wearing the Sense, my old galaxy watch and my wife's charge 5. I decided to sent my Sense back, HR during workout is a key feature for me.

Bad luck, I really liked the dashboard, design, battery lifetime, app's  etc.

May be I come back at point in time a sense 2 or something similar is released.

[pjruggeri]

Perhaps you or someone from FitBit could provide some kind of time line on a fix. This has quite obviously been an issue for months and months. Other than this quite generic reply which is often seen there has been little but silence from Fitbit. Customer service gives the exact answer you do and none of those suggestions correct the issue. I for one would like to know when the watch I paid hundreds of dollars for will work with the accuracy that’s always touted by Fitbit. 

[SunsetRunner]

@pjruggeri , it would help if you edit your post and add the name of the Fitbit person you are addressing to. Most of us are just users, with no links to Fitbit.

[MarkMM]

I was having a beast of a week last week. Finished over 30,000 calories and 3000 zone minutes. Friday night I went back to the Versa 3 (same heart rate technology as Sense) thinking maybe something changed on Fitbits end. Saturday went for  a short hard walk as it was raining lightly. 15 minutes. 0 zone minutes. Switched back to the Versa 1 as soon as I got home. 

[DeftClutz]

Why is this marked as solved when the fitbit employee stated there was no resolution?

[SunsetRunner]

@JackDrake  mentioned The Quantified Scientist on Youtube and rightly so.

To complement @t.parker  great contribution, here is the link to maybe the best video around addressing Sense heart rate accuracy compared to other devices, mostly the Polar H10 chest strap, currently considered the "golden standard" for heart rate accuracy on fitness activities. For those of you interested on a scientific and rigourous approach to Sense heart rate accuracy, it's definitely worth watching.

[Frammus]

I haven’t seen a Fitbit with accurate heartbeat detection since the very early Fitbits. I have the sense and it’s incredibly inaccurate. So far the only accurate smartwatch that I trust for HR is the apple watch. 

[Tgisele]

@Frammus my Ionic that just died was very accurate. I tested it against a few other devices and it was always close if not exact. 

-------------------------

@DeftClutz good question. 

[Tdif]

Hi I am also a costumer looking for answers lol --
Teresa Di Fonzo

[SonicMojo]

Clearly the Fitbit employee is either trying to score points for closing the most forum posts is a set time frame to improve their position at the company or they have no idea what they are talking about. After watching the video link that Miquel60 provided - it is clear beyond any doubt that this issue is NOT solved and any employee or anyone saying it is - does not have a clue in this area.

My big takeaway from the video was the delay in tracking a heartrate increase - that is what is really burning me right now. 

That said - I am thrilled that I have until Oct 28 to return my Sense for a full refund and may just parlay that into an Apple Watch once and for all. If I was 24 years ols I probably would let it slide but at 59 years now - it is very important for me to know exactly where the ole ticker is at when I get into a hard workout at the gym.

I do not want to wear anything (or give any data) to any device that is not accurate.

Cheers

Sonic

[Irish57]

Excellent point!Today was test two for Sense versus my elliptical heart
rate sensor. After minor initial workout both were at 120! As time and
intensity increased discrepancies became pronounced. Sense 111 and
elliptical 151! I can handle a 10 point discrepancy but 40! I have CAD,
purchased Sense to help but cannot trust it at 64 years of age. Trying to
keep heart issue in check and improved!
I’m going to explore an Apple as well it’s just the cost!

[Windman]

It seems that the Sense has a lag in some situations (I always use a Garmin chestbelt when excerxising to control my heart rate). F.ex going uphil with normal cadence increases my pulse sometimes may be above 150 bpm. The sense typically shows below 100 for the first 20 minutes but may then increase to 140.  If I start running, the pulse as shown by Sense may icrease even if my real pulse is deceasing f.ex

after walking uphill and the running downhill. Above 100 bpm I do not know what the Sense is showing, only that its not pulse. In average data from a Sense recorded excerize is 20 to 30 bpm lower than the Garmin. Wearing the Sense tight has a positive effect on readings I have noticed, though that may be individual.

[SleepyxEquus]

I put it so tight that my hand started feeling like it was going numb. 😂

[Irish57]

Today’s update Sense versus elliptical! Sense 97, elliptical 145! 
Attaching photos of the nonsensical response from the Fitbit techs!

 

 

 Tey beyond my comprehension! 

[SleepyxEquus]

They will just keep telling you that, because they don’t want to come out and tell you they sold you something that doesn’t work the way it should. I am sending my Charge 5 out in todays mail and better get my full refund back. As I noticed on the refund email I got that it states “This is an estimate. Actual refund amount is subject to applied discounts, tax, shipping costs, and item condition.”

I legit better get my price I paid for it back, minus the $5.95 they soaked me on for the return. Or they are so not going to like me. 

[t.parker]

@Irish57 it's a pretty standard Fitbit's response. I've been commenting on that in the past. A person has only one heart. There is only one heart rate that can be correct at the time and technology has nothing to do with it. With two different readings there are only two possibilities:

- both readings are incorrect,

- one reading is correct, the other isn't.

They can't be both correct. It's obviously impossible.

On the previous page of this thread I added this response comparing PolarH10, PolarOH1 and Sense:

https://community.fitbit.com/t5/Sense/Heart-rate-inaccurate-on-Fitbit-Sense/m-p/4979354/highlight/tr...

PolarH10 and PolarOH1 use different technologies, too (one is ECG, the other optical), yet the results overlap while Sense shows very different results. PolarOH1 matches PolarH10 (different technologies). Sense doesn't match PolarOH1 (same technologies, both are optical sensors).

By justifying bad readings with differences in technology of readings I risk saying that Fitbit may not be qualified enough to design and manufacture such hardware.