HR on Charge 3 not accurate DURING TREADMILL EXERCISE APP

[MrMarv]

First off, I am a big supporter of the Fitbit devices and their firmware programmers - not as much of a cheerleader sometimes for their app and web development teams (probably Project Leaders and Quality Insurance or maybe the people that push them to market too soon), but I still respect them.

And for the most part, the Charge 3 has been holding its own in the bpm area - when it says 108 and I count 27 beats in 15 seconds I smile. And it rarely disappoints me.

Until I put it into exercise mode, that is.

And I have held off until the latest firmware update came through last night so I could run another short test.

Last night and tonight I performed two treadmill exercises, 14 and 7 minutes in length at 2.2 and 2.5 mph.

For the first exercise last night, I did my normal 50 squat reps and crunches and by the time I took a short break and hit the treadmill at 2.2 mph my HR was up to 100 and increased to 137 (low to mid peak) by the 5 minute mark. All expected; I'm not a youngster, after all. At 6:10 it was at 100 and ten seconds later, at 63 bpm!!! Huh? It started a little climb but by 8:30 it was at 61 bpm. This is for a 66 year old male with a pacemaker/defibrillator with a resting heart rate of 68 to 72. I ended the exercise after 14 minutes at a recorded 111 bpm.

And the chart of the activity definitely shows those three minutes as being under fat burn zone of over 77 bpm.

This evening I performed no pre-walk exercises, unless you count helping clean up after dinner, and started my session at 86 bpm. At 2:00 into the walk I was down to 74 and at 1:59 I was at 71. Up to 84 at 2:20 and back down to 66 at 2:35. From there on, with me increasing the pace to 2.5 mph at 4:00 and 3.0 man at 6:00, it quickly made its way back to fluctuating between 101 and 114, finishing at 104 bpm at 7:00. 

What the heck? There is no way I'm going to drop lower than 90 bpm in those scenarios. I didn't stop to take my pulse manually during those two abnormalities, but trust me, I will tomorrow.

Moderator edit: updated subject for clarity

Original poster edit - Moderator did not clarify, but rather muddied it up.

[Blackish]

Maybe you can try tightening the strap? Use it on your other wrist? In my experience the Charge3 heartrate sensor is very good, I’ve compared it to the results measured by a Garmin heartrate strap in a few excercises and it was solid every time.

[SunsetRunner]

Actually, i find the HR during excercise to be really really bad. Wearing a chestband ánd tomtom watch to compareerde, but the charge 3 logs a heartrate of 40+ bpm every time o enable excercise mode. Strap is right, cant go any tighter and the placement is good (same spot as i wore my charge2). Problem seems to be happening whenever you move your arms the most.when stationary it stops down 50'ish bpm within 30secs.

Imho this is really really bad,i bought the charge 3 as an upgrade, right now this is just a poorly performing product.

[MVS2018]

Heartbeat of mines isn't accurate either. I'm now checking if the strap works better when not that tight.

[MrMarv]

@Blackish - 

I should have mentioned that while I was a little concerned prior to the firmware update, it wasn't that bad. But after the update? Horrendous is probably a good word.

Device position and "snugness" were identical for all four Treadmill exercises, and while I am aware of how some people get better results by moving the device up the arm, it has never been an issue with me.

But I'll be testing with the device up two inches from the "normal" position on tonights exercise.

Thanks for your input.

[SilviaW]

I’m having the same issue and I’m getting really frustrated, this is my first FitBit and I’m pretty disappointed.

I tried to adjust the strap and the positioning multiple times but I’m having this issue at least once during every workout, plus this morning I woke up and my HR shown was 54 when my resting HR is 62-64, and found out no HR was recorded all through the night.

[MVS2018]

Mine is now very low on the wrist and not tight at all. Still measures everything. I will try it tomorrow with high impact.

[MarreFitbit]

Hello everyone! Sorry to hear that you're having inconveniences with the heart rate readings on your Charge 3. Thanks for following some tips and recommendations, nice way to! 

Our heart-rate tracking technology, known as PurePulse, is specially designed to give you a more complete picture of your health and fitness. As with all heart-rate tracking technology, whether a chest strap or a wrist-based sensor, accuracy is affected by personal physiology, location of wear, and type of movement. 

For tips on wrist placement and how to wear your Fitbit device for best heart-rate tracking results, please see our help article: What impacts the accuracy of my heart-rate readings?

You can also try moving your device to your other wrist.

Heart rate tracking may not work with certain accessory bands, especially if they’re loose fitting. For best results, we recommend wearing a Fitbit-branded classic or sport band during exercise. For more information, see: What should I know about my heart rate data?

Hope this helps, I'll be around! 

[MrMarv]

@Blackish and @MarreFitbit -

Another test last night with the device one inch higher on the arm.

One small dip for a short period of time into high fat burn (quite acceptable) and then "rock steady" in cardio and right on each time I compared it to a manual count.

I did say, I was a believer, it's this is the first time I've had to move a device to get back on track as far as the heart rate goes.

Not quite ready to mark as solved, but pretty close.

[MVS2018]

Nice that this is working! I moved mine front left arm to right arm and i have the feeling that it is more accurate now. Lost Heartbeat a few time but it measures peaks better. I wear it looser than before.

[DougYVR]

I just replaced my Charge 2 (“irreparable” after 2 years less a week) with a Charge 3 this week... and I, too, was shocked to read my HR while running today... 203 bpm! For a guy with a resting HR, that’s quite a feat - considering that I’d hardly broken a sweat yet. 

Last week, while considering whether to replace my Charge or not, I returned to my Polar strap with Bluetooth, which along with the new Polar app on my phone, worked flawlessly for HR tracking. But of course, with no other features that make the Fitbit more attractive. 

I really hope this HR sensing software improves soon, or it’s going back to the store next week. 

[SunsetRunner]

I too have found that the Charge 3 is not quite accurate. When doing things that I know forced my heart to a higher rate and registered as higher on my Charge 2, the same did not happen with my Charge 3.  I was jogging in place tonight and the Charge 3 had my heart rate at 107. The Charge 2 would have had me at 115 or higher. My body is hurting from all the exercise I've had to do to get my calories with the Charge 3. I reset it this morning and it performed better, but after I got up and came into work it seems to be performing worse. I'm going to give it a month before I make a decision. Mine already had an issue with the charging cable as well, and they had to replace it.

[dianef99tf99]

Hi 

I am experiencing the same issue with my Charge 3.  I have had it less than a week, replacing my Charge 2 which is now dead.  I am really disappointed in the HR measurements. 
They are consistently lower than what my Charge 2 would have read, given my exertion.  Also, if I move around a lot, which is necessary for any HIIT or MMA workouts, the HR stops reading.  Any suggestions?

BTW - I am happy with the other features.  if we can fix the HR tracking I would be a happy customer.

[MVS2018]

I just did a workout and he lost the Pulse several times. Very annoying. During exercise pulse drops down to 80 while i feel that my pulse is raising.

After an exercise pulse goes down and up again while i am not doing anything. 

Very dissapoining. I'm thinking of sending it back.

[Blackish]

You can try to wear it tighter when working out, a bit higher up your arm, use your other wrist, reset the tracker before working out, read the wrist placement guidelines again and follow them.

My workouts include running and cycling and in the 4 hours of running this week the heartrate has not even dropped once and it picked up sprints very fast (vs Garmin chest strap). In other words: the Charge3 could work.

During cycling sessions it has dropped 2 times on rough terrain in 4 workouts. Still better than my Garmin watch. I really hope it will work out for you too.

[dianef99tf99]

Thank you I will try wearing it on my other wrist.  I had tried wearing it tighter and higher up, but it did not fix the tracking.  I will give you one Idea a try tomorrow.

[Schipper]

MrMarv- where did you find those graphs showing the heart beat by numbers not just percent of goal? Is this an app I can add to laptop Fitbit account? The one that currently shows is a blue back ground with colors indicating cardio rate by percent, and colors that indicate heartbeat with red being at or approaching max heart rate, and green at resting.

[Schipper]

none of those links provide me with a way to read the number of heart beats that are indicated by a graph line of peaks and lows within the set max and min. Any suggestions?

[DougYVR]

UPDATE: Today I ran 12k while simultaneously wearing my Charge 3 (with iOS Fitbit app) AND my Polar Bluetooth chest strap (with iOS Polar Beat app).  

It confirmed my earlier observation that, WHILE EXERCISING, the Fitbit measures wildly higher HR than my Polar. 

Charge 3:

MAX HR: 206 bpm around the 2.5k mark

AVG HR: 142 bpm

Polar chest strap (Bluetooth):

MAX HR: 160 bpm around 1k mark

AVG HR: 137 bpm

(It's interesting to read that others are actually experiencing the opposite... that their Charge 3 is reading lower HR than actual)

NB - I should also note that when I'm NOT exercising, the Charge 3 and the Polar measure both the same HR.  

¯\_(ツ)_/¯

[paolosangeles]

I'm really frustrated with the charge 3's heart rate monitor. It is way off compared to my charge 2. The difference is about 40-50bpm when I'm on the elliptical. It sucks cause I was really excited to upgrade to the charge 3. I am now considering returning it and just go back to my charge 2.