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?

[enext]

I will get Polar OH 1 strap  for my workouts and weight sessions in order to get accurate heart beat reading. I am afraid I will never get accurate heart beat reading with Fitbit Sense. Polar OH 1 is my solution to this.

[Beezy1978]

Yay! I’m glad someone else’s is working properly now, too! 😎🤓😎

I was so happy when I re-attached my Sense to my account- I was coming up on the closure of my 15-day Best Buy return window, and had gone back to my Versa... well, after re-adding my Sense and restarting it? The heart rate is right in! I count manually for 15 seconds then times by four, or ten seconds then times by six. I’m very pleased with my ‘Bit, now that the main features will be accurate! I was concerned to say the *least*, as I’d been looking forward to the Sense for awhile.

im so happy you are happy now!

[Beezy1978]

Remove it from your account, then after a day or two add it back. 
For some reason that seems to be helping a lot of people. I feel your upset, for sure! I was the same way when my Yoga tracked as zero active zone minutes! However, keep your watch. It appears they’re fixing it, or it needs to be worn for a bit, I’m not sure but many of us are experiencing renewed accuracy as far as hr is concerned! 😘 

[Beezy1978]

How unintelligent.

you won’t try something for yourself. You’ll just read input on a HELP forum and a assuming yours won’t work?

this is where ppl with problems come. You've a brand-new watch you aren’t even going to TRY? Smh.

[enext]

Fitbit and Apple Watch are just not heart beat accurate during intense workouts, some people might be ok with that, but I need my heart beat to be accurate. I like Fitbit and will keep it as a watch, but for weight lifting and CrossFit I will use Polar OH1 strap. It’s too bad that Fitbit is not making straps bands like Polar OH1. Watches on your wrist will never be accurate and Sense is just too complex watch. More health watch then anything else. It’s just my opinion, sorry.

[SunsetRunner]

@Beezy1978 wrote:

How unintelligent.

you won’t try something for yourself. You’ll just read input on a HELP forum and a assuming yours won’t work?

this is where ppl with problems come. You've a brand-new watch you aren’t even going to TRY? Smh.

---

Thank you so much for your help. I appreciate it.

To clarify, this forum was the deciding factor that formed my decision to return the Sense - the "last straw" as it were. If you noticed in my post, there were two other points that drove me to return the watch:

1. Online reviewers have found the same problem: inaccurate heart rate readings. Reviewers are showing that not only is the Sense WAY OFF when compared to a chest strap (which is understandable to a point, as optical measurements are never going to be as accurate as a strap), but it's WAY off compared to other optical trackers! That's not good, as Fitbit is touting the Sense's accuracy as one of its new features.

2. I got "burned" by Fitbit last year when I bought (and then returned) a Versa 2, due to, yes, inaccurate heart rate readings. This device read 100+ bpm when I was siting in an easy chair watching TV! The reading should have read in the low to mid 50's (Hmmm...maybe I should have kept the Sense...it would have balanced out the higher than normal readings of the Versa 2).

Online reviews of the Venu show that the heart rate readings are reasonably accurate when compared to a chest strap and in relation to other trackers. That's good enough for me.

I apologize for being unintelligent.

smh

[SunsetRunner]

@Beezy1978 we get it! Your Fitbit works after restarting, summoning the Gods of fire, and a human sacrifice. Good for you! 

No need to call anyone "unintelligent". We are a community here to help people and support eachother. 

Have you nothing else to do then comment on this thread? 😊

[steveo57]

I pretty much agree with Micsb's Conclusion that the Sense is fairly slow to respond initially and slow to decline, which works out pretty well for a prolonged workout and somewhat balances out, BUT for shorter burst such as weights or aerobic exercises and others this does not balance out. Whether this can be fixed across the board, or as he suggests another complete mode for shorter burst exercises.  I do not know how Fitbits algorithms work but some adjustments need to be made either in the overall slow response or the individual such as weights or aerobics etc.  Probably the easiest fix would be to fix the algorithm where it is quicker to respond UP and DOWN.

[steveo57]

I pretty much agree with Micsb's Conclusion that the Sense is fairly slow to respond initially and slow to decline, which works out pretty well for a prolonged workout and somewhat balances out, BUT for shorter burst such as weights or aerobic exercises and others this does not balance out. Whether this can be fixed across the board, or as he suggests another complete mode for shorter burst exercises. I do not know how Fitbits algorithms work but some adjustments need to be made either in the overall slow response or the individual such as weights or aerobics etc. Probably the easiest fix would be to fix the algorithm where it is quicker to respond UP and DOWN.

[Beummie]

I have been in touch with the helpdesk several times now and I get a useless story about the differene in algorhytms between Ionic and Sense. Now the advise is to wait for a software update.

this is very frustrating as my heartrate during exercises is appr. 40 bpm off!

[SunsetRunner]

Happy to learn the issues can be fixed with a software update. Promising 🙏🏾

[Micsb]

Hi Steveo57. Yes, it is most likely never going to be precise related to certain short burst exercises, not because it is a Sense, but because it is an optical sensor placed on the wrist. Maybe some changes can make it smarter however it will always be lacking behind as it need a larger number of measure points to use its algoritm and estimate/calculate the heartrate.

According to the below citation the HR would jump up and down if it didnt use multiple measuring points to estimate the HR.

"The wrist-based monitor can also get tripped up if you tend to do a lot of exercises involving wrist bending or quick movement. The oximeter works by measuring the movement of your blood using light. When you flex your wrist, you can momentarily change that circulation, leading to erroneous heart readings (If you've ever seen an Apple Watch reading of "65bpm" or lower or a gray number when you're in the middle of a high-intensity workout, that's likely what has happened)."

From the following page: https://www.imore.com/best-external-heart-rate-monitors-iphone-and-apple-watch 

All the recommended monitors are placed elsewhere than the wrist. 

[Micsb]

Can the Sense or other Fitbits work when positioned higher up the arm with another strap for weightlifting? Here is a couple of snips regarding the general problem with a wrist monitor and weightlifting.

https://forums.macrumors.com/threads/heart-rate-monitor-weightlifting.2126559/ 

"The optical sensor the Watch uses won't return an accurate reading any time blood flow to the extremities is restricted... like it is during weight training. To get an accurate HR reading while weight training, you'll need a chest strap sensor synced to the Watch via Bluetooth."

"You can burn a decent amount of calories weight training BUT...weight training is anaerobic (unless you are doing HIIT or Cross Fit) so your HR is NOT an indicator or measuring tool for calories burned and there is not good method to calculate. You really only need to monitor your HR while lifting if you have a medical condition or just curiosity. Overall though you are correct and you need to do cardio workouts also in order to burn fat effectively."

[Texxy]

They told me faulty sensors so just sent my back

[Texxy]

I got told it's a faulty sensor as during excursion my HR was lower than when I was sitting down lol, just sent it back and charging my ionic back up .....

[sportionary]

I was just on live chat with Fitbit as well with the same dang issue.  Check this out.  We bought 2 Sense's.  One for myself and one for my wife.  Mine has the issue with the HR during activity.  I did a full hour today with a personal trainer that kicked my butt and got 0 active minutes.  On my Ionic same 60 minute workout I would get 80-100 activity minutes,  However I wore my wife's sense last week one day for my workout with my personal trainer and it tracked perfectly.  Fitbit chat basically had nothing to say today.  Blah, blah blah restart here is your ticket number.  Hit us up if you have the issue tomorrow.  Trust me, I've restarted this thing, tried lowering my HR zones, ect over the past 3 weeks and nothing works.  Super frustrating and about ready to ask for a return, and go back to using my Ionic.

[sportionary]

Did they mention when the software update will be coming out?

[Lazywalker]

Mine seems to be behaving better around the heart rate; well it now measures a higher rate even though it lags behind my chest belt  quite a bit; but I haven’t done all my normal classes yet so I’m not 100% convinced.

Unfortunately the restart problem had got a lot worse. I’ll wake up in the morning and the Fitbit will restart, I put it onto charge while I shower - it restarts; I’ll have breakfast - it restarts and so on throughout the day.

So now during exercise besides it pausing every so often it restarts completely every so often meaning I’m having problems confirming whether the heart rate is ok for all exercises. 

I wish there was a pattern to it but I haven’t found one yet

Eagerly awaiting a new software / firmware fix

[supercad79]

For the past two days I haven't been able to get the HR up enough on the watch to get into my active zones. To make matters worse, since I've lost over 80 lbs the app recalculated my HR zones and now my fat burn zone starts at 4 beats higher than what it was. So now I have to get it up that much more. Seeing as how my wife and I both have the same watch I wanted to try something.

This morning I did a factory reset on both of our watches and tried to swap hers for mine, just to see if I got the same results. Her watch synced with my phone flawlessly and I was up and running in no time. My watch had trouble connecting to her phone, trouble getting the Wi-Fi setup, and downloading the update was taking forever. So this wasn't an option at this moment because she had to get to work.

So I reverse-swapped our watches back to the way they were, and suddenly my watch was set up just as quickly as hers. So I'm going to try and see if this did anything, and if not I'll try the swap again tonight and test tomorrow. If I can't get it to work after all of that, I'll have to get Fitbit to exchange it because I can't take it back to the store anymore (only a 14 day return/exchange window on wearables).

[Beezy1978]

I’m sorry but if you won’t open the box and try it out yourself and determine whether the heart rate monitor is accurate yourself then yes you are unintelligent. But whatever, do you. SMH