Inaccurate heart rate when walking uphill

[Berengal]

I've had Ionic for almost a month now and I've noticed that the heart rate monitor fails whenever I walk uphill, showing a heart rate of less than 100 when it's at least 140.

This walk should clearly demonstrate the problem as I hold a steady pace both uphill and downhill but uphill I'm between 80-100 all the way while downhill I'm between 120-140. On the relatively flat part right before the top it seemed to work for a short while and my measured heart rate shot up to 170 peak, which is about what I'd expect going up that hill (150-170 bpm for the whole climb). On the final climb it again loses signal once I start climbing and the final reading was 116 bpm. Once I got my shoes off, 30 seconds after stopping the exercise on the watch, it said my heart rate was 150 bpm.

I have tried wearing it every way imaginable: low on the wrist, high on the arm, tight, loose, on top of the wrist or underneath in every combination to every degree. In every case I get a good reading on flat or downhill ground but a poor reading going uphill. It works fine getting everyday heart rate and it also works fine on other exercises. I've done spinning and circuit training at a gym and it had no problem capturing heart rates above 150 on either of those.

[CcCham]

Hi, I’d love to know what happened with this?  I have the same problem with my versa 2 - low heart rate going uphill and high heart rate coming down. It seems to measure accurately when running on the flat. It’s rather frustrating as I live in the mountains and so a lot of my treasuring time is spent on hills. Look forward to any advice. 

[clarys]

I ended up getting another charge 4 under warranty as it stopped working completely when Fitbit did an update. I'm now on my 3rd Charge 4 in 10 months and the latest one seems to work ok, which just highlights how inaccurate the previous one was. I won't be buying another Fitbit.

[RGFrankfurt]

I have the same problem with Versa 2 both walking and cycling. Heart rate is around 70 as I climb a hill panting, only rising to a more reasonable 140 when I get to the top. I too have tried all the advice about positioning it, resetting it etc and it makes no difference. This is obviously a common issue and before I abandon the brand to try to find something more accurate, I would like to know if any of their newer models have fixed the problem or whether they ever investigated it (rather than blame the user for wearing it wrong).

[SheilaTeves]

Any new info on this? I regularly go hiking and my HR doesn't go above 120 BPM but when I go for runs on flat roads, my HR gets to 170 BPM. It can't be right

[DeeC321]

I'd also love to know if FitBit are looking into this. I had this issue for years with my Alta HR and have just got a Luxe hoping it would be different but I went on a hill hike yesterday and it kept saying I was at about 100 BPM when I was definitely more like 150 going up a steep hill. It's really frustrating because otherwise I really love FitBit but it makes me wonder if the rest of its metrics are inaccurate too....

[HiTekDrifter]

Hello there,
I never did solve the inaccurate rate, which for me happened when walking downhill. But I did solve a problem with measuring heart rate while swimming, which may or may not work for you: I covered the Fitbit Ionic with opaque fabric (SPF 50+), and turned off automatic swim detection (which started suppressing all heart rate measurement after a software update), and then it worked great. The covering extended around my wrist and inches in both directions, it is a skin tight rash guard. Maybe you can try rigging that up for walking. Good luck. Alas, the wrist band on my Fitbit broke last year, and I lost it. Haven’t replaced it, I felt like I had learned enough from it.— hi Tek drifter

Hello Sheila, actually my pulse runs around 110 while hiking up a 10% average grade (I do it weekly), while it goes up to 150 ie running at a fairly slow pace, and my Fitbit Ionic measured my pulse accurately in those contexts. My problem was walking back down the same 10% grade the Ionic would register 130+, although my actual pulse would be 70-80. And it did this consistently across a number of months. I had different issues while swimming with it, where sometimes it reflected my actual pulse and sometimes it would be way off in either direction. I realize you are concerned with running and walking but please hear me out: Fitbit clearly states that it doesn’t support heart rate measurement while swimming. But that’s what I mainly do. The reason it doesn’t recognize pulse while swimming is likely all the sunlight reflecting through the water, bouncing off pool bottoms, etc. so I tried covering the watch with a skintight long sleeve “rash guard” which is rated SPF 50+. Covered the rest of my torso, but the point is, it completely shielded the Ionic from reflected sunlight. And then it accurately captures my pulse while swimming, for an hour or more! Of course, it is difficult to peek at it while swimming, as peeling the rash guard off it is a chore, but at the end of a workout, I would look at the captured heart rate and be satisfied it was accurate. So, back to running and walking,perhaps try covering your Fitbit completely, so it is shielded from outside light, and see if that helps with the accuracy. Good luck!

Sent from my iPad

Moderator edit: merged reply

[Steves9999]

Same thing happens on the Sense and Charge 3

[agrover02]

@MarreFitbit @EdsonFitbit @JuanJoFitbit 

It's been almost 6 years since this post was started, with many people over the years claiming they have the same issue.  EdsonFitbit said that the team was looking into the issue, and yet there's been no update here since then?
I have a Charge 5 and it has the exact same issue.  My heart rate was 180 today power walking up a mountain, and the fitbit read 85.  This happens not just once and a while but every time I use the hiking activity tracking (but is not an issue for martial arts, swimming, or kickboxing).  All of my zone minutes come from walking back down the mountain, because apparently I didn't work hard at all going uphill 🤣

I have read and tried the articles on proper fit, restarting the Fitbit, all of the above, and nothing works. As someone who only has a Fitbit for the Fitness aspect, it's very disappointing.   Fitbit reps, please provide us an update?