Exercise heartrate way off

[dopeydwerg]

Hi,

Recently I switched from the Ionic to the new Sense. But the heartrate during exercises is not very accurate. Actually it's way off comparing with the records of the same exercises of the ionic.

My average heart rate during Weights was normally around 109bpm but now it's 74bpm. for sure this can not be right? And the other day I played squash and I used the tennis exercise to log it and it said my hr never went above 109 while normally it peaks around 165. Is there something wrong with my fitbit sense or is this a common bug?

[SunsetRunner]

I can understand if it wasn't working during the lifts, as most optical sensors don't work then. However, it seems to never catch up and keeps showing low HR long into the rest period. And when it finally catches up, my HR is almost at rest by then. Really frustrating

[supercad79]

Last night I went for a walk and after 6.28 miles I was in the fat burn zone 74.59% of the time, which is close to what I was averaging when I used my Ionic (78.03%). I stopped half way through to manually take my heart rate from my neck and it was actually on par with what the watch was showing. I'll do it again tonight to see if I get the same result.

The only thing I had done differently was wear the watch as close to my hand as possible (which is the opposite of what they tell you do to) and had it one notch tighter.

[Lazywalker]

Just had a response from support telling me to remove and reinstall sense from account. Just done that and will see if any improvement. 

They have also responded to my other issue about my sense restarting randomly several times a day, by suggesting unbelievably that I restart my sense!

[supercad79]

My Sense appears to be working correctly now. For the last 4 walking sessions the HR being recorded by the watch matched when I had taken manually, and I'm getting all of my active points now.

[Lazywalker]

Hopefully mine will be ok, but I won’t know until I’ve done some intense HIIT and spinning sessions



Sent from my iPhone

[Lazywalker]

I reinstalled and restarted the watch yesterday

So far I’ve found some improvement as the sense only restarted twice yesterday

I did two classes yesterday but can’t really comment on whether the heart rate has improved until I’ve done a wider variety and other classes

I can say that it did register higher heart rate during my body combat class, but the display seemed to lag. For instance I was doing the Mai Tai (intensive session) and it showed my heart rate at about 110 when I was breathless and sweating; then when we paused before the next track which was less intensive it shot up to 150 before going down again. 

I suspect it was measuring the heart rate but the display lagged behind

I’ll be able to say more in a few days when I do other classes

[Amanc1990]

I think thats a general thing with optical sensors. I just did a run having bought my sense yesterday.

Just a note it did an update while setting up.

I did a run outside just to test the HR and GPS(used map my run on my samsung). The HR seems to be in line with my old Samsung in terms of consistentcy. It got up to 183bpm max, I think its still lower than the true high as I did a hill sprint to finish but overall positive (graph below)

 

[Tanya2020]

Guys, 

I’m very disappointed as I did the watch reset following service support instruction but it still fails to show the right heart rate. 

Yesterday I did yoga and sense showed that my average heart rate was 82 compared to the ionic which was always around 105 for this type of exercise. Obviously I was not assigned with any active minutes which upsets me a lot. 

Today I swim in the sea for around 30 min. Due to the low heart rate the watch even didn’t recognize it as an exercise and again I didn’t earn any active minutes.

This all makes me very upset. I’m 100% sure I wear and use them correctly, I restarted my sense mane time and I did a reset. Not sure what to do. 

[supercad79]

Tanya, can you wear the watch one notch tighter than you usually do? That what I did and the watch is as close to my hand as possible, not the one to two fingers up the arm like they suggest. After doing these two things my watch is accurately tracking my heart rate and giving me my zone minutes.

Also, just to check accuracy, can you get your heart rate up and manually check it? That's what I had to do to verify that the watch was working correctly.

[Tanya2020]

Hi Supercad79! I tried to wear the sense tighter and run another test and it seems it works well this way 😊 thank you! I’ll try to run another few tests tomorrow when I’ll go to the sea again 🏊

[Wassermann80]

For me there is no fix. I can´t get the WHR work correct.

[SunsetRunner]

Wow! I bought (and then returned) a Versa 2 last year due to inaccuracies in heart rate. I went back to my ionic. I decided to try the Sense based on “Pure Pulse 2.0.” I figured they touted the accuracy of this tech so much that it HAD to be better. 

I have not opened the unit yet, and it’s going back to the retailer tomorrow. Based on reviews and this thread, I see I should have done more research.

I’m going for a Garmin Venu. It’s a little more expensive, but at least that freaking heart rate monitor works!

I’m done with Fitbit. QC is awful.

[SunsetRunner]

WOW! That’s unbelievable! Literally: it’s not a bug; It’s a FEATURE!

[SunsetRunner]

I also find that when I'm excercising I can be on 254 BMP milliseconds later a dramatic drop to 125 BMP and a further decrease to 112 bpm.

Honestly while my heart rate fixes and restarting kind of worked. There's still something off about this device 

[Tanya2020]

My today’s mail to customer service, AGAIN AND AGAIN:

Dear Fitbit support,

Good day ! It’s my fourths complaint about the same problem that hasn’t been yet fixed since one week. 

I urgently need a clear answer from you about when and how you are going to fix a heart rate monitor of my new Fitbit sense?!!

Today I had 3 swimming sessions and I put both - sense and ionic on my arms to compare the heart rate reading. The heart rate on sense watch didn’t go higher than 95-105 while ionic showed 110-120 AT THE SAME TIME. 

Therefore, Fitbit Sense didnt recognize the exercises (3 swimming sessions yesterday and another 3 swimming sessions today) and it didn’t assign to me any active minutes during the exercises. 

I urgently need a clear answer from you about when and how you are going to fix a heart rate monitor of my new Fitbit sense?!!

Regards

Tanya

[Tanya2020]

Apparently being polite with them doesn’t help much 

[Tanya2020]

Honestly, I just tired keep testing this watch which makes me extremely upset and angry. I just issued a refund. Not sure if I will buy a new Sense right away, wait for few month or go for another brand. So disappointed with Fitbit Sense. 

[SunsetRunner]

I have a similar issue.

When I am doing some cardio on the treadmill daily I always sit around 120-130 bpm when wearing my fitbit Blaze. Now with the new fitbit Sense its always sitting around 90-105 bpm. I even wore both at once on either arm to double check and yes, they're measuring it differently. I put on a Garmin heart rate monitor that straps to your chest to double check, the older fitbit Blaze is much more accurate than the fitbit Sense currently is.

I had even tried doing a full sprint on an incline for 2 minutes and my heart rate while wearing the sense barely hit 115 bpm. Clearly there is an issue.

I tried restarting it, then wearing the old one, then going back to the new one; like others had suggested for a solution in this thread but it changed nothing. As for doing the ECG and having an affect on solving this problem; if that is the case then I won't be able to solve the problem because ECG isn't available on the Sense in my country for the foreseeable future.

[SunsetRunner]

Loosening or tightening does nothing for me unfortunately.

[Micsb]

I have upgraded from Inspire HR and noticed a similar drop i HR during some exersises. 

I dusted off my old Polar watch with chest HR monitor for comparison as I got a little concerned reading above. What I found is the Sense is very accurate however it is slow to react compared to the chest monitor. The Sense is quicker than my Inspire HR. the Inspire would during brisk walks put me in the 110-120 HR range, provide plenty of zone minuttes where the Sense keep me just below 100. This make me wonder if some of the problems above is similar, that the older watches where inaccurate compared to the newer Sense and not the other way around?

I have added a couple of pictures comparing the two watches. During steady walking, either slow or brisk, the HR is very accurate. Climbing a steep hill, the Sense falls behind and only reach similar HR at the top of the hill, thereafter it takes a bit before the HR drop down during rests.

Conclusion: My copy of the Sense is accurate but as expected not useable for short burst high intensity training. What it need is a special profile when selecting weight lifting exercise where it give priority to quick changes rather than precise readouts.

Steady walk Polar 99 Sense 98Walk small hill Polar 106 Sense 105High hill Polar 150 Sense 105Top of hill Polar 144 Sense 140Short break Polar 101 Sense143