Charge 6 heart rate monitor is pathetic

[Markrrrrr]

I just got my new Charge 6 after my Charge 5 was bricked with the firmware update.

I was hoping the heart rate monitor would be more reliable than the Charge 5 but I'm afraid it's actually worse!

As an example, my heart rate gets up to about 135 doing weighted squats but the Charge 6 hovers around 77 and consequently my weight training workouts are showing as zero zone minutes.

Does anyone have the same experience or any thoughts?

Thanks, Mark

[Triletics]

I may be here a devil's advocate but I don't think there is any reliable wrist sensor that does good job during weight training (at least not in my experience and I use several brands of watches and HRMs). Bending wrist and getting a pump changes a lot for the sensor which works observing your blood flow. Additionally, weight lifting sets may be too short to observe increase of heart rate for the sensor under such conditions (although Charge 6 managed to capture even 15 seconds stride intervals which elevate HR even higher and quicker but running doesn't affect arms). If you go with ie. Garmin, you'll see the same problem for exactly the same reasons. For such workouts, chest straps has been invented which monitor heart rate, not blood flow. Fitbit will have such a problem until it support external heart rate monitors. Wearing HR sensor on the wrist sometimes simply won't work.

[Markrrrrr]

Everything you say is reasonable except I can compare it to my previous Charge 5 which did capture the weightlifting reasonably well. The Charge 6 doesn't capture it at all.

[Triletics · Accepted solution]

@Markrrrrr I never owned Charge 5 so can't speak for its HR tracking quality. I owned Charge 2, Ionic, Sense, Sense 2 and now Charge 6. Charge 2 worked kind of decently but weight training wasn't tracked even remotely correct. Ionic, Sense and Sense 2 were even worse (Ionic often didn't read my HR at all, just showing two dashes). Mind that I always compare with chest strap (PolarH10 and now also Garmin HRMPro+). Charge 6 so far produced quite good results but not for everything I do. When running, it likes occasionally to lock onto my cadence (which happened on two runs). The biggest surprise is that it's very accurate in the water (swimming). Today's swim also confirmed it. It does pretty well with higher heart rates (HIIT intervals, short strides, fartlek) and indoor cycling. Not trying to defend it but my tests which I posted in another thread (I compare raw data within the same time domain) show improvement compared to all Fitbits I owned before. Weight training and outdoor cycling are on my list to test. Wrist OHRs pretty much suck when it comes to exercising (I always use a chest strap connected to a Garmin watch, I use wrist HR only when testing something or I forget the chest strap). I'm curious what is your frame of reference for Charge 5 accuracy? It's quite interesting as that would be the very first Fitbit that I've heard of that handles weight training well (I may get one just to check it 😀).

[Markrrrrr]

@Triletics Thanks for detailed reply, you've had a lot more experience than me. I wouldn't suggest getting a Charge 5 based upon my comments but the 5 did capture my heart rate pretty well on high intensity sets such as weighted squats. I compared it to counting my heartbeats manually anmd the difference is obvious.....77 versus about 135. I also have a Polar H10 but I just want the one app to use for my everyday exercise/sleep/step counts etc rather than working across 2 apps. 

The Charge 6 seems to do quite well with jogging and high intensity sprints although I think it inflates the very high heart rate stuff.....I'll actually try the H10 in comparison to check based upon your experience.

Overall I like the Charge 6 but since my goal is to keep track of my general fitness it's disappointing that it doesn't capture my main form of exercise.

Cheers

[Coulaa]

I’ve had a Verse 4 for 3 months and now the heart rate tracking is totally off suddenly!  Like no credit for activity.  I compared it to my old Apple Watch and it’s like night and day.  So it’s a Fitbit problem not device specific.

[Mcav75]

I've used various wearable for around 10 years now, and the charge 6 is the best wrist-mounted heart monitor I've used. It's much more accurate than the sense 2 for example, and matches very closely to my dedicated HRM. Quantified Scientist on YouTube found the heart rate monitoring on this watch to be excellent, even in high intensity. 

My experience with the watch is the same.

[Mcav75]

I am not doubting your experience. This sounds like an issue with your watch though. My Charge 6 is handling my weight sessions very well across multiple movement types.

[detchicago]

Hi Markrrrrr, I just got my new Charge 6 and use it daily for water aerobics and I experience the exact same results as you do.  I know I was getting a cardio workout based upon my breathing yet I did not get any cardio zone minutes.  My one hour water workouts that were both strength and cardio on Charge 5 were averaging at least 80 to 100 zone minutes.  With the Charge 6 with the same intensity workouts I am getting at most 20 zone minutes for the entire hour.  This does not seem right.