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

[UnguruBulan]

The more the days pass by, the more I realize it may be just a matter of time until my Sense will start acting up big with the HR readings.
While I was only looking at the "overall picture", I can see some posts here focus on the fine details.
I'm seeing some little oddities now and then, which for now I consider negligible, like in on this recent treadmill exercise (speed 6.3 miles/hr, incline 5%, duration 40 mins). While the overall pattern is expected I think, I circled the little hiccups that were recorded during the run. 

Treadmill 6.3mph speed, 5% incline, 40 minutes duration

[NazH]

I just tested the Sense against my old Fitbit Alta HR, one on the right and the other on the left wrist. They both had the same heart rate, and actually recorded 34 minutes of cardio out of 40 minutes, which is what I normally did with the Alta HR. I repositioned the Sense 2 fingers width apart from the bone on my wrist, seemed to help with the accuracy. Hope it stays that way. 

[Monikalew]

I figured it out past the return date 


Sent from the all new AOL app for iOS

[Monikalew]

I am up to date, and it seems to be worse.
😞


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[MrMogo]

I have to admit that when I commented about the heart rate monitor not being accurate  (it starts slow, and takes a long time to record actual heart rate when on a X-country ski elliptical machine) I was feeling a bit exploited.  After reading comments and doing some online research as well as my own, I guess I'm no longer that concerned.  First, like someone else posted somewhere  I could increase the accuracy of my Sense by moving it up my arm away from my wrist.  The guiding rule is two fingers (or for me about an inch).  This helped a lot; at least enough that I don't feel that screwed when on the elliptical.  The secret here is to move it up on your arm further, and try not to bounce that arm around a lot.   Also, after googling "fitbit sense accuracy" I found some good youtube videos where some European guy did some pretty good accuracy tests of the heart rate, sleep, step counting, and really, though not as accurate as a chest monitor, I didn't think it was that bad.  And the good news is that comparing accuracy over time, the European guy concluded that Fitbit is making tweaks to their accuracy (though again, if you're banging your arm around like doing freeweights you'll miss the rapid changes in heart rate and get more of a smoothed average).

It isn't a medical device so assume you're getting an approximate reading of heart rate and calories.  Otherwise, for the $199 I paid for it, I get a lot of cool information related to health that just wasn't there before.  Combined with my Aria weight scale (which is pretty accurate) and a Omicron BP/EKG monitor, I'm feeling like I'm doing okay.  If you're a professional athlete, consider a chest monitor for the best accuracy.

[t.parker]

@MrMogo  you say "and try not to bounce that arm around a lot" - shouldn't I be focusing on my workout rather than on whether I bounce my arm a lot because the watch has problems with HR? Then the watch is a distraction from the workout and it's better not to wear it at all. I can't imagine doing pushups, bouldering, and even running without bouncing my arm 🙂 I can't imagine myself on the climbing wall making sure I don't move my wrist too much (focusing on that would definitely affect climbing technique) or doing ie. clapping pushups but just not too hard because the watch may not like it 🙂 My tests show that Sense indeed is very sensitive to external noise (which during my runs appear as HR matching or almost matching my running cadence so it's not only bouncing arm but also bouncing the whole body during running).

"If you're a professional athlete, consider a chest monitor for the best accuracy." - 100% agree with that and I would add to consider professional watch, too.

[NazH]

With my previous Fitbit Alta HR, which is still good and works, was very accurate, regardless of bouncing my arms around. Obviously using the guideline of how to position the device. As I trusted my old device, it was time for an upgrade, which is why I have the Fitbit Sense.

Fitbit are aware of the low heart rate issue and is looking to fix it. I won't stop contacting them until they do. The more people complain to them directly via chat or phone, they will have to fix it. 

[MrMogo]

of course you're right.  A fitness watch that can't handle athletic moves is kind of ridiculous.  Until something comes along that is both accurate and has all the other supporting features that Sense has (the phone app and websites are superb) I'm going to accept the fact that again, it's approximate at best.  But for professionals, it's kind of a joke and Fitbit should do something about it.

[TommyIzzo]

@MrMogo You keep mentioning professionals. How about Fitness people who had a handful of prior models since the Blaze that they could be happy with? This isn't Fitbits first rodeo. The phone app and websites aren't new either. Wasn't their whole business model based on getting people moving, prior to the Sense? I never even tried setting up Fitbit pay, as I knew the watch didn't do what I bought it for, out of the box. 

[SunsetRunner]

DID IT AGAIN!!!! THIS ISSUE IS NOT resolved.

Just got off a 32 minute bike ride, all seemed well and normal. Last .75 miles I sprinted (normally heart rate should enter/approach peak. Came around the last turn where it is safe to check my HR and it is at 82... down from 134 shortly before I started the sprint.

Also took 2 minutes to connect to GPS.

Not sure what the point is if:

1. You have to stand around and wait for your workout to begin

2. Your fitness quest ends catastrophically because you go head first into a car while checking your fitness tracker to see if it has, once again, dropped your HR.

It kills me that they list this as 'solved' and have no comment on similar posts. (I get emails from FB about a thread I started asking if my issue is resolved). "Not until I return the watch and get a *ar*in" is not an option.

Mattie

[SunsetRunner]

Forgot to include, got off the bike, ended the 'bike' exercise, walked to end of my driveway and HR had risen from 82 (end of ride in exercise app) to 124... got 4 minutes of fat burn after ride, but none in last 4 minutes of ride.

[MrMogo]

I probably should not have been some specific.  I would say anyone who takes their fitness seriously from trainers to normal people who regularly go to the gym.  I'm just saying that for some of us, having an "approximate" idea that we're getting our 10,000 steps and 2400 calories is acceptable.  But I also understand that for a lot of people (professionals, trainers, and those serious enough to work out regularly) the accuracy is pretty disappointing.

[UnguruBulan]

@MrMogo I guess I'd be annoyed too by a shocking and unjustified HR plunge like @SunsetRunner and a few others reported (i.e. from 130-ish down to 80-ish while increasing the effort intensity level). And I don't consider myself a profi athlete although I am consistent enough with the exercising over the past few decades, amateur level.

That kind of inaccuracy is actually something really bad and would probably be a deal breaker for me, luckily so far I'm not seeing that on my Sense.

[opiatedsherpa]

It's interesting to see the number of complaints about the Sense and the lack of acknowledgement from Fitbit.  I'm a long time Fitbit user (since 2014) and I'm certainly not going to go anywhere if they were to acknowledge the issue, but I can understand the new users who are still on the fence about the product, may venture away with said acknowledgement.  If it's a software issue, then figure it out.  If it's a hardware issue, go back to the Ionic setup and apologize accordingly with an appropriate discount.  Is that too much to ask?

[TommyIzzo]

@opiatedsherpa We are probably in the minority. Most newer users like the SP02 and stuff? It hasn't been a big enough factor that Fitbit openly acknowledges it. And they're running sales. 

[Guitarplayer]

I noticed that @SilviaFitbit, authors of best answer, is no longer posting since more than one month. Maybe @AndreaFitbit and @EdsonFitbit, who looks very active in this section of the forum, can follow up this lenghty issue. Much appreciated.

[opiatedsherpa]

I would agree that there is a minority here, but there's a good chance that the majority of Sense units are exactly the same and the majority just doesn't care about the heart rate monitor accuracy.  That is the biggest letdown of this issue.

[UnguruBulan]

@opiatedsherpa that chance, is in my opinion, close to zero. Just looking at the original issue "HR won’t ever get above 120bpm" - that doesn't seem to happen to my Sense. Another noticeable complaint was the HR suddenly and sharply drops while exercising - that doesn't seem to happen to my Sense.

Maybe you're on about that in general, the HR read doesn't perfectly reflect the reality? If that so, that could be what the majority of the users tolerate, myself included; for just a couple hundred bucks cost, I personal don't expect this "toy" to be the perfect medicinal product and give me the exact HR, every time.

[opiatedsherpa]

@UnguruBulan yes, I agree with most of those points and you're likely in the majority of users.  Just being in this forum likely is in a minority of Sense users and that's understandable.  Yes, I am in a minority of a minority that I actually give a care about these numbers and for Fitbit to say that the Sense can warn you if your heart is racing or is beating slowly, there is a major concern for its accuracy.  

The Zone minutes is arguably a hokey statistic, but I think it's a true sign of activity.  I go a little over-the-top with my numbers tracking, keeping a detailed spreadsheet of most statistics that the Fitbit is supposed to provide and when I changed from the Ionic to the Sense, my exercise didn't change, but the Active Zone minutes fell off a cliff.  

I love being active, I love statistics and measuring "accurately" those numbers to stay accountable to stay accountable to myself is very important.  If the battery on my 4-year old Ionic wasn't terrible, I'd likely go back to it.

[obermd]

- If someone can't tell if their heart is racing or beating too slowly then they have other problems and really need to see a cardiologist.

- The Zone minutes was a change a couple of years ago by the American Heart Association.  Fitbit simply adjusted to reflect that change, but it would be nice to be able to track both.

If you want "hokey", take a look at the history of the 10,000 step goal.  Short story - it was a marketing gimmick by a Japanese fitness company back in the mid-60s.

As for my Sense, it's close enough for me as it tracks the trends that are important.  I'm a swimmer and any wrist/laser based HR monitor is going to have difficulties.  For runners, this may not be the best option, but for swimmers it's a good option.