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

[SunsetRunner]

There are so many reviews on YouTube mentioning the inaccurate heart rate that it's not funny

[Spray99]

There ever a fix for this? I got the run around from support.  Pretty disappointed.  It's around 50 BPM off for me when weightlifting.  I deadlift 500+ and typically I'm in the 170's for heart rate...the sense will show 110-115.  I wish I was in that good of cardio shape. 

Really angry I spent so much on an inferior product to my older fitbit. 

[Brendån]

Is it just me, or did they do a hot fix? Though my software version hasn't changed, my accuracy seems much closer to other devices in the last week

[SunsetRunner]

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@Brendån wrote:

Is it just me, or did they do a hot fix? Though my software version hasn't changed, my accuracy seems much closer to other devices in the last week

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Now that you mention it, since around Thursday of last week my Sense has been showing a HR that's much more typical of my range. I haven't seen much "cardio" at all going back months, but for my last 3-4 logged days of exercise I've had a much more appropriate amount. For me it started on June 3rd. For example, looking back over the past several months I've had anywhere from 0%-10% cardio during a workout, but over the past several days I'm logging 50-80% in cardio which is much closer to what I was expecting.

I'm still waiting on the new firmware that's being rolled out (Sense Firmware Update OS 5.2 - 128.5.38), so I know it isn't related to that. Even stranger is that the last update on my phone was 2 weeks ago. Now I'm curious, if they did fix this issue, how did they do it?

[tvaughan95]

I've found that the heart rate is not dependent on the heart, but rather the movement of the arm it's on. Example: 1 min of jumping jacks (starting at the beginning, no other exercises performed) and the heart rate will show 120+ bpm. However, after 20 mins of HIIT where you're out of breath, you can feel your heart racing and are covered in sweat, the BPM will register 70+ bpm. It's way off, and the easy way to beat the system is just move your arm up and down. Great for cheating. Problem is, I'm not doing this to cheat. It's sad...

[pjruggeri]

I discovered this too while sanding and painting. Repetitive movement of the arms throws it off wildly.

[Evil_Monkey]

Has anyone started a petition to see if we can get Fitbit to address this? 

[Fit058]

I think there are several threads / bug-tracker etc., but it seems, that inaccuracy is one of the main features of this device.

But I think, the heart rate measurement is quite okay, while gps tracking is ..... very inaccurate.

[JanelleRae]

I bought my Fitbit Sense last October, and the heart rate during exercise has never been correct.  I do HIIT training twice a week and now wear my Versa 2 on one arm and the Fitbit Sense on the other.  The Versa 2 shows my real heart rate and the Sense is stupidly wrong.  During HIIT training the Sense heart rate is at least 30 beats per minute lower than it should be.  I frequently have 155 beats per minute on the Versa while the Sense shows 105 to 120.  I have called into support multiple times and they say that they are "working" on it but nothing ever happens.  I don't believe that they are ever going to fix this.  It is a danger for a 57 year old woman to work out at high intensities and register such low heart rates.

[Strikes]

Incredibly disappointed with Fitbit sense heart rate accuracy. Mine shows about 40 to 50 lower during HIIT or really any high intensity spin class. Very disappointed. Going to cancel premium and look into Garmin. Been with Fitbit for over 5 years. 

[gbass]

I too have noticed this. I am actually a cardiac scientist by profession and can confidently say from checking my own pulse that often the sense is underestimating my HR by almost half during a workout. The problem seems to be short bursts of exercise where the HR increases quickly - the sensor in the Fitbit can’t keep up.

Does anyone know if Fitbit intend on rectifying this? The recent firmware update doesn’t mention it as an issue?

[SleepyxEquus]

They sadly will not recall their items ever…they will just blame it on people not knowing how to use them right..I wore my Ionic, I’m only replacing it because the GPS keeps going out on it more and more…Ionic has me working out at 179BPM and Sense 81BPM…like what!?! 

[Chasemanley]

Horrible horrible waste of money, my heart rate will go from 90 to 150's from one song on my drum set, then I'll feel my heart and it's not near as fast as what this worthless device says 

Moderator Edit: Formatting

[Dabears0825]

That should probably be NON Sense.  I wish I had done some more research for a smart watch to integrate with Android, but I had used Fitbit for so long that I guess I just took a leap of faith. Sent from my Verizon, Samsung Galaxy smartphone

[SleepyxEquus]

Same! I only went with it because my friend told me it was replacing my Ionic. Which mine started losing my heart rate during workout and I needed my numbers, so I bought the sense. Work ionic on my left wrist and sense on my right and was so mad it was no where near my Ionic, which I take all the numbers with a grain of salt..but it was saying I was in 130 heart rate. When I was pretty much almost jogging and sweating to death and breathing labored and it then started to drop to 120…while ionic said I was 185..like a ton miffed with it. 

[SunsetRunner]

I am on my 4th fit bit I have been trying for years to get them to read my heartrate correctly. I cant count the times I have contacted them and they end up just giving me the same links to look at that didnt work the other 20 plus times.  If you exercise to hard it cant read your heart rate, they have chosen to fill the sense with all the bells and whistles instead of improving the heart rate accuracy.  It should be called the sitbit because that is the only time it works.

[pjgra]

I tried all that as well.  I’m a road cyclist, and they recommend wearing it higher above your wrist—worked once, not the next day, and when your sweating it’s not easy to keep it from moving. 
very aggravating and want to go back to my ionic.   Never had that issue! 

[ZenTashi]

I did not, If I’m not exercising it’s fairly accurate but during exercise there is just a huge lag.  I’ll probably switch to another device, for the price, bugs are too many and too frequent.

[iWearKneeSocks]

I’ve started using the Cardiogram app in the background and linked it to fitbit.. it picks up a lot of the lag and logs per minute and not every five. Often times it will also alter me I’m over 120-130 where my fitbit only logged like a 90 max. 
it’s still not accurate based off of my testing it out during stress tests at the hospital when I log maybe 130 on Cardiogram but they have me at 160 - but it’s still helpful because the fitbit app still only had me at like a 90 max during those tests. 
It’s worth. Try to link the two and I just kind of check Cardiogram for the HR stuff instead of fitbit.  There’s times on my fitbit when I look down and it says 130-160 but in the actual fitbit app it never actually logs those numbers. 
There’s  definitely a lag issue that needs to be addressed… I don’t remember this w/ my original versa. 
Considering I just paid like $300 for this one I’m going to roll w/ it for a bit and keep my hopes up it gets addressed because I like using the fitbit app to log my weight since I have an aria and my foods and water and everything… I’d rather not switch to a different maker and have to separate my logging of materials between more apps. But if it’s not fixed in another yea I’m just buying an Apple Watch - which I’ve read also has some lag issues,  but from people I’ve seen who have them they get way more accurate numbers than I do. 

[pjgra]

Since I had just recently purchased my Fitbit Sense with warranty they
allowed me to send it back. Ordered Apple Watch..