Heart rate monitor not accurate during exercise

[Admroe]

Hi, so I bought my first ever Fitbit  (Charge 3) as a way to help me measure and monitor my level of activity (mainly at the gym). I need to keep my heart rate at a constant rate for fat burning.

Wore it today for the first time at the gym and it just sat at no more than 80bpm. I checked using the gym monitor and I was up at 140bpm. How can something called a Fitbit that is supposed to be about monitoring levels of activity be so inaccurate? 

PS: after about 30-40 minutes of session it suddenly shot up to 150bpm.

I’m hoping this was a one off and net time it is more accurate otherwise I think I’ll have to be emailing Fitbit directly.

Is this a common issue and if so has anyone found a way to increase accuracy?

thanks

[MirelaSA]

I used that feature once for sleep tracking and it gave me basic awake/restless and asleep. You're supposed to not use the feature to track your sleep cycles. Just go to sleep with the tracker and let it be. Don't touch the app. You should get your sleep cycles.

[wind77]

Can anyone try to wipe dry the HR sensor and the skin, before taking HR measurement?

If my suspicion is right, the HR sensor will not be able to take the readings correctly, if it comes in contact with sweat/moist.

Yea, it does sound stupid, but so is the fact that Apple Watch thinks a banana is alive.

https://www.abacusnews.com/digital-life/why-xiaomis-fitness-tracker-detecting-heartbeat-roll-toilet-...

[rs2018]

I tried that dozens of time and it didnt change a thing.  Also doesnt stand to reason why all else being equal the charge 2 works under the exact same conditions

[wind77]

Fitbit claimed that it is an "improved" HR sensor.

How is it improved, we are not told.

Giving Fitbit the benefit of doubt, it may be more sensitive to swear/moist than Charge 2, and thus I wonder if wiping dry the sensor and skin would help with the situation.

As you clearly indicated that the accuracy is still affected, I guess I should be looking elsewhere.

Thanks for the feedback from all the early testers!

[SunsetRunner]

Yeah, sadly it seems to be weaker than the Charge 2, not improved. I'm so disappointed and hope that they can fix it. I will be returning the 3 and sticking with the 2. 

[wind77]

my Charge 2 battery has spoilt - doesn't last 36 hrs per charge.

I was looking at the newly announced Charge 3 with much enthusiasm then.

But looking at Fitbit forum and how Fitbit staff/moderator attending to queries, I got suspicion and decided not to jump into early purchase.

Thank god I was not impulsive.

But with my Charge 2 gone, I will have to find replacement elsewhere.

[dcc2013]

Experiencing same issue with heart rate accuracy woth Charge 3. (Have had a Charge 2 for two years.)  Restarted as you suggest.  I will let you know if it fixes the issue.

[Blackish]

The heart rate sensor is the same as the Ionic and Versa. In my experience (three days and two excercises) the sensor is MUCH more accurate than the Charge 2 sensor. When running the Charge3 is always within a beat of with my Garmin FR935. I’ve used the ChargeHR, the Charge2 and the Ionic and (for me!) the heartratesensor is on par with the Ionic. So, I’m very happy with the heartrate tracking of my Charge3!

[rs2018]

Its not the same sensor - turn over the model and look  - you'll see on the charge 3 there is 1 green light. The charge 2 has 2 sensors which are also brighter.  Don't believe what's written - look for yourself.  Pure pulse which may be what you're referring to is more the software and algorithms that interpret the signals the hardware provides.  The hardware (sensor) is different.  Anyways, glad its working for someone.  

[dcc2013]

First image shows Heart rate for an elliptical session in September on my Charge two.  The second is an identical elliptical session today with a Charge 3.  Obviously, very different.  I restarted the Charge 3 as someone from fitbit recommended.

I wonder if Fitbit didn't rush the development of the Charge 3.  Odd that the clock faces are not as extensive as the charge 2 (none with today's date) and now they are saying others will be added.  Why did they take sales before it was ready to ship.  I called Customer Service and had a very poor experience.  Poor english.  Argued with me that there might be a problem with my Charge 3.  I assume they have outsourced customer service.

[rs2018]

Same thing I'm experiencing as well as many other users on this post.  I have 2 years worth of data doing the same workout with the same general hr footprint on charge 2 and i have 3 days that aren't anywhere close the the previous 2 years.  The conclusion i came too is that new features and battery life were traded for HR accuracy.  If you look at the sensors (see previous post) .. it says it all .. of course in addition to the empirical evidence.  They wanted to take credit for new features as SP02 that arent even operational nor were they in previous advertised models. The release date was pushed from 10/1 to 10/7 .. i waited patiently only to be disappointed ... i have to agree with you ... they rushed something ... they didn't stick to their core base (HR accuracy and community) and I think the response will speak for itself.  If you want to track steps you dont need a fitbit ... if you want a HR monitor you probably exercise and want to track it accurately... very disappointed.  

[SunsetRunner · Accepted solution]

Same issues here, had a charge 2 which was decent but the charge 3 is completely off at heartrate monitoring. It shows 40+ bpm bpm compared to my running watch and chestband. Ridiculous 

[Admroe]

Pleased to say I seem to have it sorted! 

I called the customer service number and they were surprisingly helpful. 

I have updated my charge with latest releases and changed the way I wear it. so far it’s been within a few bpm of the gym hr tracker. Starting to gain confidence in it after all. I shall keep my eye on things but so far so good.

Worth looking at this https://help.fitbit.com/articles/en_US/Help_article/1565 if you’re having issues

[SunsetRunner]

Doesn't make a difference for me, also the latest firmware didn't seem to improve it. Next to that, been using the charge 2 for over a year on the same wrist placement without trouble so that's also a pointer this degice is just lacking performance. 

[SunsetRunner]

That's great! Are you able to share what advice they gave you, if it might us? If not, no worries.... Glad it worked for you!

[SunsetRunner]

Two examples comparing the data the Charge 3 logs, and the data that my TomTom Spark 3 logs. The readings the TT Spark3 logs are in line with the readings I got from the chestband I was wearing (to check the differences in HR data) but the difference can quite clearly be seen. 

[Admroe]

LadyA77 they suggested I follow the guides online and sent me a link. The most useful one is here https://help.fitbit.com/articles/en_US/Help_article/1582 

Hope it works for you too 

[wind77]

@SunsetRunner I enlarged your content to 200%, and I still cannot figure out what is on the picture.

Hope you have a better way to show the data.

[SunsetRunner]

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@Admroe wrote:

LadyA77 they suggested I follow the guides online and sent me a link. The most useful one is here https://help.fitbit.com/articles/en_US/Help_article/1582 

Hope it works for you too 

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@Admroe, the link is not coming up. Can you try to repost it? Thanks!!!

[SunsetRunner]

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@wind77 wrote:

@SunsetRunner I enlarged your content to 200%, and I still cannot figure out what is on the picture.

Hope you have a better way to show the data.

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uploaded the images to tinypic, this board reduces their size :

http://oi64.tinypic.com/2q8ugyc.jpg
http://oi65.tinypic.com/2u7b040.jpg

Hope these links work here, and you can see it more clearly this way. The heartrate logged by the charge3 is constantly higher, and has odd spikes.