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

[m-umar]

FYI upon enquiring the latest from Fitbit is that issues is known to them but there is no definite ETA. Google has plenty of coders around and 1-2 of them could be given the task to find out whether or not the problem is H/W or S/W and then Fitbit (Google) can decide upon the action to rectify it.

[Frammus]

yup.. i got the same response months ago… good luck with that..

[m-umar]

Hi @Irish57  totally agree with all the comments here.  It is very disappointing indeed. My heart fitness use to hover around 56 but since the use of Sense it has dropped to 51 rather than going on the other side with regular exercises. Stats of my yesterday 's run were so far off and lagging behind that I stopped looking at the sense. Like lot of others here the HR is all over the place when one is really pushing hard. I could feel my heart beat in my ears but sense was showing 127 HR and it took a while to show me 141 and at that time I was actually slowing down. At one time time I had to stop to tie my shoe laces and within 1-2 minutes of starting again it showed it around 161 just for an instance. I was hardly speeding/pushing at this time.  I regret taking this sense with me on my every run and problem is you can have only one device attached to app.

I also climb up & down the overhead bridge and don't even go there about the HR. It is just a piece of junk on our wrists.😠 On the Fitbit web site pure pulse is still been promoted as the greatest invention to hit our lives! REALLY.

[IgorR11]

I was participating a lot in the forums looking for a possible solution, but unfortunately nothing has been updated to fix this error, unfortunately fitbit is omitting the flaw.
I went back to my other watch that gives me accurate information and I leave the fitbit most of the time in the drawer, I only use it to monitor my sleep, and that's it.

[m-umar]

Just checking if anyone's situation changed since there is deafening silence from Fitbit 😭

Or is the case here blind (Google) leading the blind (Fitbit)

[Frammus]

Silence so far. I’ve powered mine off and using my apple watch. Not as user friendly but dead on accurate.

[m-umar]

Very Interesting Review about sense. Found this on another post here but not sure it violates cross posting or not. Since more users are following this thread so I thought it is a better place for it.

https://www.youtube.com/watch?v=7-u8VTmeDF0

[m-umar]

Just watched the above analysis and interesting point is that he think it is a software related issue. he points out that sense detects drop in HR and also acceptably accurate at the lower HR which can't be H/W or light emitting diodes etc.

Conclusion is that Fitbit released this device without proper & thorough testing especially thinking of algorithm which detects/calculates HR at intervals.

And current users are the test lab.

But is anyone at Firbt (Google) actively working on the fix is question!

[Irish57]

Heart rate continues to be highly inaccurate thus impacting calories, zone
minutes and well, everything!!

[rryanhayes]

I’ve been doing some experimenting since my initial post and have figured out a workaround for my Sense that gets me much more accurate data when I am working out. Unfortunately what I’ve found also makes me think this is a hardware issue and not necessarily a software issue. I started wearing my Sense 2 fingers up my wrist, tightened to the hole next to the one I usually wear the band on, and then pinning my Sense to this part of my wrist with a wrist sweat band so that the watch can’t move. I have gotten the most accurate results I’ve ever had in the year I’ve owned this device the last 4 workout sessions I have done this. I started to notice that my readings became inaccurate when the watch would shift on my wrist during a workout, when excess sweat would get under the watch during a workout, or when the watch would break contact with my skin anytime during a workout. Keeping the watch pinned in one place with a sweatband has given me consistent accurate results. Based on my DIY experimentation with this, I’m pretty sure this isn’t something that can be fixed via a software update and that’s why FitBit isn’t saying anything. It seems to be a flaw in the design of the watch’s hardware tech and it’s need for constant uninterrupted contact with the same place on a persons skin to give accurate readings. 

[SunsetRunner]

@rryanhayes , that's consistent with my experience. I didn't use a sweat band, but my best HR results so far were when using the watch band really tight, so that the watch moves as little as possible.

The sweat band is a great idea if you don't need to see the watch numbers during workout.

I agree the problem is probably hardware, but for other reason. No code professional works on this for a year and still has no solution. It's their own hardware, designed by them, not some alien device!

---

UPDATE:

Having said that, with some types of repetitive arm movements, the HR results are still quite bad, always, even with the watch "glued" to the wrist.

[glodanM]

Hello,

Same thing happens to me : 14 km of hike and only 4 zone minutes on the Sense. Unbelievable. And on top of it, the stress management is not working since days, the gps is only internal etc... Charge 4 was really good....

[Irish57]

Thank you for the information. How sad that those hoops have to be jumped
to gain more accurate readings from the Sense!
To clarify do you place the wrist sweatband directly below the Sense?
Thank you!

[glodanM]

I don't have a sweat band. Just the sense on my hand. 

[Irish57]

Gave this a try today, not much success at all especially on the elliptical. Was hoping it would work despite the sadness of having to try tricks to fix an inadequate Sense! I may give it a try again tomorrow! 
I like to glance at the Sense too when exercising and it prohibited that! Thanks though!

[robymaje]

I so wish that I had read these posts before I bought my sense. My heart rate when exercising was so extremely high during a couple of my warmups that I immediately stopped after the 2nd one and checked in with another device I knew was accurate. Now I wear a heart monitor when I exercise because I can’t rely on the Sense at all except when I am still. I upgraded from a charge to be able to use it to swim with it and did not expect that the technology for heart rate monitoring to be so inferior to the charge. 

[robymaje]

I’ve been using Fitbits for many years-maybe up to 10 years- and the inaccuracy of the heart rate technology in the Sense is a dealbreaker for me. 

[simon87]

Hi, my response from Fitbit was to purchase a new fitbit model with a 30%
discount which doesn't apply to the new charge 5 & absolutely disgraceful!
from some recent reviews the charge 5 has the same issue 😑

[JackDrake]

I can confirm that the charge 5 doesn't have this issue. I had the sense some days, compared it as facing the low HR issue with a galaxy watch and my wife's charge 5. Both GW and C5 showed realistic measurements. So, I've bought a Charge 5 for me as well. What I've seen during some minutes on a crosstrainer with built in HR (more or less not the best measurements): I had to tighten the strap a little bit more than ususal. This is also recommended by fitbit and the HR seemed to be accurate. Wearing it to loose showed to low HR.

Looking for the quantified scientist (youtube) might be helpful.

[Marmelade]

Totally agree with you, re the high readings.

it happened to me a while back as I came back from a walk, 1h30 - a walk mind you, not a run nor a jog - and sitting back home my heart went to 165 + and going up and up; I totally freaked out, took the Sense out and put it on the table where I could not peek !

i have been known, medically, to have sometimes an irregular heartbeat, but the whole point of having the watch was to get on top of this and monitor it. 
so now I mistrust the watch and it was suppose to help.