Fitbit Sense and Heart Rate

[mperry9701]

I just bought the Sense and noticed the heart rate monitoring is way too low.  My Ionic was much more accurate.  Has anyone else noticed this?  

[imjrode]

What are you comparing it to? I did a workout for the first time yesterday with my Sense and Garmin chest strap. The Sense lagged behind by a few seconds when I eased off or did intense bursts, but during "steady" portions, was within a beat or two usually.

Assuming the algorithm might need to be tinkered with.

[mperry9701]

The Ionic.  Read my original post.  I also measured the "old way" with two fingers on my neck.  It has been way off since I bought it a week ago.  Technical support is clueless.

[rfjouben]

I received my Sense about two hours ago and I am wearing it on my left wrist and mu Ionic on my right. The sense is about 10-15 beats higher especially right after I activate from the sleep mode. 

I also ran test against my pulse on an Oximeters, two different types of blood pressure cuff and the old fashion way by taking in manually at the wrist and carotid artery (the neck). So far the Ionic is closer to the other devices and my manual pulse rate.

[techcop]

I agree. The heart rate on the Sense is off quite a bit. How I know? When taking my blood pressure and comparing my pulse rate from the BP device and Sense, the Sense is usually higher.  For example, the BP device showed my pulse at 64. The Sense, (while sitting) showed 94 and then after a few seconds decreased to about 62. Strange.

If I get on the treadmill, and while checking my pulse while on the treadmill it is over 120 bpm. On the Sense, it hasn't gotten over 96. In fact, during my exercise it stays at 96. I upgraded from the Versa 2. I may have to go back to the Versa 2 or exchange the Sense for the Versa 3 if this continues.

I've already factory reset the Sense thinking that might help, but it hasn't so far.  

[mperry9701]

Thank you.  

Mark

[imjrode]

I haven't really had any issues in terms of my resting heart rate. It seems to be pretty in line with my Garmin Vivoactive 3 and has less wild variation.

Where my Vivoactive 3 and Garmin Dual chest strap have been better is with changes in intensity with workouts, much like dcrainmaker pointed out in his review. The Sense seems to lag in picking up those changes. But, after 5 seconds or so tends to get back within a beat or two per minute.

If you're seeing crazy variations where you're running at the same pace and the Sense is consistently like 20 BPM off the entire run, I'd venture to guess it's a hardware issue. You could trying RMAing it and getting a new Sense.

If you're just seeing it lag and then it's roughly the same as other HRMs I'm guessing it's probably just a software fix.

For me, personally, it's not off by enough to force me to return it. Yet, anyway.

[Fra.84]

same problem with me, with gym training based on strength and maximal, heart rate during training struggles to overcome the 100 beats per second, and during the whole training it is around 90 beats, making a comparison with versa 2, the sense is by 20 beats per second less than average. If they don't resolve I go for a return.

[smb2808]

I have been having the same issue. When running it seems accurate, but on other workouts (such as weights or HIIT) it is not registering any heart rate change.  There is something clearly wrong with the firmware on this watch.

[jh064]

Same issue.  An hr workout is barely hitting 300 calories burned, sometimes doesn't hit that.  Same workout with ionic was over 600.  Honestly I hate this thing.

[mperry9701]

That's the exact same thing I am having.  Tech support was no help.  I am returning it and switching back to my Ionic.  Thanks for your reply!

[mperry9701]

Good to hear it is not just me.  Thanks for all of the feedback!

[Rsfreitas]

There's a scientist who published an accuracy test on YouTube, for all Sense sensors available... It's not bad at all.

Maybe it's a defective unit or you can try different positions in the wrist?

Mine seems pretty accurate, bit I haven't compared to my Garmin or pressure monitor yet.

[imjrode]

FWIW, this is who @Rsfreitas is referencing, I believe: https://www.youtube.com/watch?v=w6D_uUDUP2k

I've watched his stuff in the past. Thanks for sharing.

[lee_h39]

I have the opposite problem, mine is reading far higher than my old charge 2 and compared to manually measuring the Sense is over reading by about 25 on a walk and I’m seeing averages of 10 plus higher on my normal run and peak of about 12 higher. Have arranged to return it. 

[KingConn500]

I also am having irregularities with my hr readings. My hr is showing much higher than normal when I’m not active. 

[jachang]

I also had the Charge 2, and it was extremely accurate. This new Sense is always inaccurate, showing BPM much higher than actual.  With the Charge 2, I could compare heart rate to actual physical monitoring as well as with my BP cuff, and it was always exactly right.  This thing is pretty useless for measuring heart rate.

[lee_h39]

Mine raises by 10bpm when I lift my wrist to look at it. 

[Wassermann80]

same problem with me, with gym training based on strength and maximal, heart rate during training struggles to overcome the 100 beats per second, and during the whole training it is around 90 beats, making a comparison with gwa2, the sense is by 10-20 beats per second less than average.

24/7 readings are also very strange.

[Wassermann80]

The following video shows the problem of the sense:

https://www.youtube.com/watch?v=7-u8VTmeDF0

If it´s a software issue, please fix it.