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

[Gary45]

Well this thread has just saved me a lot of money. I was about to buy a Charge 3 in the hope that it would be better at tracking my heart rate during exercise than my Charge 2. It clearly won’t. My charge 2 basically loses my heart rate as soon as I enter Peak, either completely or understating it by as much as 90 bpm compared with a chest strap. When I speak to Fitbit they just say useless guff about where to put it on your wrist etc. So clearly they haven’t figured out how to track heart rate during exercise yet so I should save my money. Thanks everyone. 

[JuanJoFitbit]

Hi everyone! I totally understand how you feel about the experience you've had with the Charge 3 heart rate monitoring. I appreciate your feedback.

I want to follow up on this and would like to know if you have tried the restart process. If you haven't done so, please follow the procedure that is listed in this help article. This will refresh your trackers internally. After this, make sure that you are not wearing your trackers too tight since this affect the heart rate tracking.

If the issue persists, let me know and I'll be happy to follow up! 

[speed_demon]

This was one of the steps that your tech support had me do, which had no impact on the problem, nor did repositioning the Charge 3 on my wrist or changing the strap tension. Note that my problem was at rest, unrelated to workout mode.

[SunsetRunner]

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@JuanJoFitbit wrote:

Hi everyone! I totally understand how you feel about the experience you've had with the Charge 3 heart rate monitoring. I appreciate your feedback.

I want to follow up on this and would like to know if you have tried the restart process. If you haven't done so, please follow the procedure that is listed in this help article. This will refresh your trackers internally. After this, make sure that you are not wearing your trackers too tight since this affect the heart rate tracking.

If the issue persists, let me know and I'll be happy to follow up! 

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Time and time again we get this answer by customer support or on this forum, while it has been stated multiple times by different users that those steps just don't fix the issues. Please start taking your users serious! 

[speed_demon]

Yes, I had already tried that reset method, as directed by your tech support.

I have my office closed on Wed afternoons, received the Charge 3 that afternoon, and spent my afternoon off trying to get it working.

None of the various reboots or other actions were successful, so I sent it back to Amazon.

I had not expected any problems with the Charge 3 since the Scosche Rhythm+ works fine for me including cycling and elliptical workouts, despite the innumerable unfavorable reviews for the Scosche and Polar electro-optical armbands on Amazon and elsewhere regarding this issue, so I discounted the complaints about earlier Fitbit monitors for the same reason.

Hard to explain why the Rhythm+ on the same arm as the Charge 3 accurately measured HR c/w the Polar H7 chest strap.

I’d like to try another one when this issue is corrected.

[dcc2013]

Hi JuanJo
Yes, I did all of that multiple times as I stated in my post to you and it made no difference. Can you please contact your development people, and let us know if they are aware of the issue and when it might be addressed? Thank you.

Moderator edit: personal info removed

[tmaaari]

Have the same problem here, im returning my Charge 3 tomorrow.. I think im trying Garmin next! Sorry for bad english, from Norway 😅

[Lilymm]

Hi,

I'm also having issues with the heart rate monitor - which is the main reason I bought the charge 3 over the cheaper Alta.

Since purchasing it I haven't had a single night where it has recorded the complex sleep data (I raised this on another thread and did not receive a solution, just advice on where to wear it which didn't make any difference). 

When working out it doesn't record heart rate properly - when I worked really hard climbing a mountain it never recorded my heart rate above fat burn on the graph, but at one point when I checked my wrist it showed 179, (also I could tell my heart was pounding).

Final nail in the coffin - this weekend I removed my fitbit as I was attending a wedding. When I checked my stats I was surprised to see that between 12 noon, and midnight on both days my fitbit recorded a phantom heartrate, constantly in fat burn or cardio mode!

At this point I would really like to consider a refund/swtiching to a cheaper model without heart rate as I now feel that the heart rate monitor is next to useless. Thoroughly disappointed.

[dcc2013]

I have a Charge 2 — the heart rate monitor works well so you might try it. Not much difference between it and a charge 3. The charge 3, they say, is waterproof and the display is supposedly better. Some of the clock displays available on the charge 2 are not yet “offered” on the 3, like date. They say it will be added later. This is really odd. For some reason the 3 was seemingly rushed to market. I am really disappointed with fitbit generally these days — my experience with the charge 3, the fact that weeks and weeks later no one has yet to acknowledge the issue, and the fact that they outsource customer service. It really makes you wonder what’s going on. I noticed in Best Buy that their inventory of fitbit accessories was next to zero. And as a matter of fact, I’m not sure if you can buy a charge 2 at this point. Best buy didn’t have one in stock.

Moderator edit: personal info removed

[Heigou]

The Costco here is sticking both the 2 and the 3. Yeah, the upgrade looked tempting, but I’m waiting until more user data is out there.

[Heigou]

As to HR on the charge 2, especially during workouts, I’ve noticed that placement is critical. I have to wear mine much further up on the forearm to get even a vaguely accurate readout.

[dcc2013]

JuanJo

No, this advice is not helpful -- restarting and wrist adjustments make no difference.  There are tons of posts here telling you the same.  Why won't Fitbit acknowledge that there's a problem with the Charge? I returned mine.  Still have my Charge 2.

[LMM519]

@pilv13   I totally agree. I bought a Charge 3 pre-release. I wore it for two weeks. My body hurt so much from trying to get my calories that I resorted to getting a Charge 2 from Amazon. The new Charge 2 I got is much more accurate. I put them both on tonight and there was an 8 HR beat difference and up to a 12 HR beat difference between them, with the Charge 3 being much lower. 8-12 Beats can mean the difference between HR Zones, and that is not good.

I am downloading the update to Charge 3 right now, and will give it one more week. If it is still significantly different, it's going back.

[HikeWithDogs]

Check the info on return deadlines. If you ordered on release day or earlier, I believe the Amazon return deadline is today (30 days). Fitbit is 45 days if you bought it from them, but they won't take it back if you bought it from Amazon.

I returned mine this weekend. Tech support was no help, just went through the script of enabling and disabling heart rate monitoring. I will buy a better-tested device for heart rate, no new Fitbit for me.

[Owlet]

I'm returning mine as well. I contacted fitbit support and after a week and a half I finally get an email from a "specialist" who claims my heart rate sensor looks to be working well. This is the graph that they looked at. This is what happens every single time I've exercised using my charge 3. My HR will be at 60 BPM for part of my workout when my actual heart rate is 170 BPM. Then it will shoot up to my actual heart rate then shoot back down to 70. Apparently these "specialists" think this is normal behavior during EXERCISE ON A TREADMILL. Even if you're slowly walking on a treadmill your HR will be higher than 60 BPM. 

So they keep denying anything is wrong and won't offer an exchange when pretty much every single one of my graphs looks like this. So I'm sending it back and I'm done with fitbit. Everything else about the charge 3 is great, except for the crappy heart rate sensor. My charge 2 was much better at tracking HR during exercise, and the charge 3 is much worse, and fitbit support does nothing about it. So it's going back. What a shame.

[dcc2013]

Hi Juan Jo

Why are you not responding to my messages and the messages of dozens of other Fitbit Community members who are pleading for an acknowledgement of the Charge 3 heart rate problem and hopefully a plan  to fix it?

Dan

[SlimJim16v]

I also noticed that the HR looked low. I compared it with my Charge 2 and a Polar chest monitor, it's reading 10 - 30 beats low on exercise and lags behind even the Charge 2 which isn't great either.

I'll be contacting customer service about returning it, however I wasn't sent/given a receipt, so don't know how it'll work.

Not impressed, might try again if/when they fix it. Surely the O2 function will improve accuracy when enabled? 

[kleebo86]

My charge 3 won’t even show my heart rate and then will either be 40+ too low. Extremely angry that I spent money on what was supposed to be an improvement. 

[SlimJim16v]

Well, returning it isn't a problem. There's an online return form and you use the order no. in your confirmation email. 

The online form didn't work, however the helpline was great and all sorted and email confirmation received.

However, my Charge 2 now won't reconnect, so a rubbish Charge 3 is better than nothing.

Also, due to the heart rate being wrong, so calories burned are also wrong, I'm guessing 100 - 200 low/day, I've been slowly losing weight since I got it. 

[HMargeson]

I just received a Fitbit Charge 3 for Christmas and have been very disappointed.  The first thing I noticed was that it tracked steps I wasn't taking.  It added approximately 100 steps when I changed from pajamas into workout clothes.  Then, another 60 or so for brushing my teeth.  I know I was still moving, but it really wasn't steps.  This wasn't a big deal, but I was very anxious to see my heartrate during vigorous exercise (specifically HIIT workouts).  The first time I used it, my heartrate measured at most in the 120s when I know it was more likely 160.  I tried checking it throughout the workout, but it wouldn't go up.  I read some things and learned I should wear it  more snugly and higher up on my arm which I did the next time.  Again, it wouldn't register the very high heartrates.  Sometimes it would increase to 147 during a 30 second break between intervals when I felt my heartrate decreasing.  Later that afternoon, I get a notification congratulating me on another workout.  When I logged in, I saw it counted the time I spent cleaning my bathroom as a workout.  This "workout" was considered 100% fatburning, but my MMA workout where I could barely breath was only 49% fat burning according the my fitbit.  I think the info from when I was cleaning the bathroom with an average of 99bpm, but I hardly believe I burned more calories doing that than the high intensity workout I had completed that morning.  Is there anything more I can do?  I thought I could try on my opposite wrist, but it is super disappointing to have such low reports for very difficult and intense workouts.  Advice appreciated!

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