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]

Having the same issue when exercising with my bowflex. My heart rate comes and goes. Ill be doing an interval training where my heart is beating out of my chest and the watch says im under zone. Funny thing is get off the machine and walk a few steps and the rate shoots up. I spoke to support and they claim not a single person has had an issue with heart rate in the sense. What can we do anout this?

[Vini]

I just did comparisons with my old Ionic (which I measured against another identical ionic with same firmware and they are the same outputs) and I also checked against my old Garmin, and still the same. They were also almost all identical to my physically taken HR. The HR during exercise is about 40-50 % difference lower on Sense, which also affects daily calories burned (and therefore mixes up my calorie intakes).  See Pictures for side-to-side comparisons in the moment, and in total....  Such an expensive device that is not accurate.... Very Disappointing....! 😞 

[Rami.Khalawi]

Yes, unfortunately.

it’s not accurate at all while exercising.

I have always to switch between my sense and my Huawei GT2 due to this issue.

[Dparini30]

The only thing that I fear will fix it is a recall on them as I feel it's a
hardware issue with the watch rather than a software issue.

[Adrockwe]

I'd also love to hear from Fitbit as to whether they have any plans to investigate this.  I've been trying to decide between the Fitbit Sense and a Garmin (Vivoactive 4 or Venu).... The Sense has the upper hand EXCEPT that I feel like its a useless decide if the HR isn't even remotely accurate.  This one feature alone is a dealbreaker for me.  If Fitbit acknowledge the problem and I know they're working to fix it I may change my mind....in the meantime, I'm leaning towards Garmin.

[Bauer24]

I’ve gone ahead an created a feature suggestion to get them to fix it. 

https://community.fitbit.com/t5/Feature-Suggestions/Fix-the-heart-rate-monitor-in-the-Sense/idi-p/46...

[ZenTashi]

I’m in a university study. They strap a polar heart monitor on me. And while the polar says 120 bpm my Fitbit sense is at  about 83.  Wasn’t expecting that big of a difference. 🤷‍:male_sign:

[7satish7]

I have the same issue, did you get it resolved by any chance? 

[Dabears0825]

2/5/2021 - Update

I'm 62 years old so my max heart rate is 158.  I was riding today and I looked at my Sense and it said 171!!!  Good for Zone points but can't be accurate...lol

2/3/2021

I'm seeing the opposite effect.  I have an under desk cycle that I use between meetings.  I usually ride for 15 minutes at a time at resistance 3 2-3 sessions a day.  When I rode today at 2pm EST, I was ramping up and noticed that it was reading 147-151.  I NEVER get that high.  I was surprised that my heart wasn't coming out of my chest.  Then about 10 minutes into it, I noticed that it went back to 101-110 which is more normal.  I used to have a Charge 4 and that seemed to show an accurate reading.

I wear it about 1/2" below my wrist as I'm in between openings so I wear it a little tighter than looser.  The only thing out of the ordinary is that I had to reboot Tuesday morning cause it stopped synching.

[Jumpjockey]

I'm sending mine back, its not acceptable to be that inaccurate with something as important as BPM..that have failed miserably on this score.?

[alex-w]

Same here, I was so surprised that the Sense heart rate accuracy is inferior to that of my old Ionic.  

I like my Sense watch and the amazing technology it packs--but it obviously needs a firmware fix.  I have no doubt that FitBit will find a solution soon--especially with the resources that the new owner (Google) brings to the table.  The Sense is their iconic watch and I am certain a fix will happen.

In all fairness to Fitbit, all the watches I have including the excellent Apple Watch 5 are often problematic with heart rate accuracy--especially in some training scenarios--for example when running or aerobics.  All optical heart-rate-sensors, no matter what brand, suffer from these limitations.  

I found the Sense gave very accurate results when measuring sleep heart rate and sedentary heart rate.  I compared these to those of medical equipment I use and they are remarkably similar.

The problems start when I start exercising.  The Ionic was a little more accurate than the Sense during exercise involving arm movements and interval training--but it also often reported the wrong heart rate intermittently.  This is also true with the Apple Watch and Garmin.

Having accurate HR during exercise is vital for me, so I started using the MAF+ earplugs that include HR and HRV.  They give  ECG-like results and are way more reliable than all the watches I own including the Apple Watch. No wrist monitor can offer the accuracy of a strap or in-ear monitors.

I have no commercial affiliation with MAF earbuds from the philmaffetone site.

Finally, I must give FitBit support the credit they deserve.  I reached out to support about the issues I am experiencing and they, after sending me the usually automated replies, took the matter seriously.  After escalating the issue to a higher level, the replies were laser-focused and personal.  I even received a phone call and spoke with a helpful fellow.  

My advice to anyone experiencing issues is to be polite and courteous, even though you may be frustrated and angry.  Hurling abuse at anyone has never helped solve any issues.  Those who are polite, patient--but firm, will get a better response. 

I think Fitbit offers the best fitness app available for my needs, there is nothing like it--and I have tried all of them.  The Fitbit Sense is a lovely watch and it brings features and options that I find helpful-- I am glad I bought it.  All that needs to happen is a firmware update that corrects some of the current issues.

[Giampi71]

I'm sorry to say but my opinion is that Sense HR sensor is practically a generator of random numbers.

[Silverback007]

What’s baffling is if you do an ECG it won’t record it as your heart rate is too high. But it doesn’t record your heart rate at that level on the app. It just won’t record over 120bpm. Fitbit need to step up here and sort the problem out.  I’m very dissatisfied and I’ve been pointing  this out for over a month now. Would someone from Fitbit address this please ASAP. My old Fitbit charge 3 was much better and more accurate watch. 

[Robjoby]

I've used various Fitbit devices over the last six years and after using my Versa 2 throughout last year with frequent very inaccurate heart rate readings whenever exercising I decided to buy the new and expensive Sense model late last year, thinking it's got to be better, considering how expensive it is and the expected technological progress being made.

How wrong I was as I am still very disappointed with the heart rate readings whilst exercising. The Strange thing is that it typically reads between 20 and 40 beats high during my treadmill routines, but it often reads a similar amount low during my weight training routines. I know this because I use a Beurer chest strap and wrist worn heart rate monitor for continuous checking and I also use a finger fit oximeter for periodic checks against my Fitbit Sense and the wrist monitor. I find generally quite good coordination between the two non Fitbit devices, with very occasional significant differences, but my Fitbit Sense is mostly reading 20 to 40 BPS different, usually higher whilst on the treadmill and nearly always lower when weight training. I've tried wearing the Fitbit higher and lower and changing wrists, wearing it on the underside of my wrist and cleaning the sensor face. Nothing improves it. Fitbit must resolve this or lose our loyalty!!!

Maybe Google can inject some much needed performance improvements now that they are very much involved!

[Anthonyrimsky]

Same problem here

I am very dissapointed with the sense

it is actually a step back from the ionic i used to have

uglieer design an worse battery life

[Bearbrook]

In the last week or so I noticed while running that it was starting to tick up or down in large increments.  It also seems high sometimes when still and then goes up or down in large increments. Something seems like it changed all of a sudden. This happens with my charge 3 but over the last two months with sense didn't experience any of that until last week. 

[Silverback007]

I just got an email from fit bit admitting there’s a problem with HR and they are aware of it but with no immediate fix. Imagine that.  They continue  to sell the product that’s defective.  If I want to return I have to go through the whole 45 day exchange process.  

[Bearbrook]

Is it hardware or software?

[Silverback007]

This is the reply (We’re aware of it, but may not be able to provide a fix in the immediate future. We'll continue to monitor the situation, and keep our team informed of the)

so i don’t know.  But tweet then publicly.  That’s the problem only  way I got a response. 

[cwilliams01]

That is my experience.  I contacted support and after the annoying automated replies I asked for a more personal reply and I got a call from a lovely lady who arranged for an escalation.