Fitbit Sense - inaccurate heart rate

[Happymouse72]

I've had various models of Fitbit since Jan 2014 and in Nov 2020 upgraded to the Sense as wanted to have the SpO2 screen and skin temperature monitoring. Clearly I have 6yrs of data and was really surprised to see my RHR suddenly increased. Also during the same walk I do everyday (due to lockdown) my HR was below zones for the majority whereas it used to be solidly in fat burn and I'd get into cardio for part of it  - it's very flat round here!. My RHR as been 60 for years and now it's 65. I tested it with a blood pressure machine and wore an old Charge HR on my other wrist at the same time. Both the BP machine and the Charge HR recorded a HR of 59-60 but the Sense recorded 72!! I have been told that the latest models have different algorithms and that is the reason but when you have a device to monitor your health a new algorithm that gives that much difference is not helpful. I've also been advised to wear the original strap and restart the device - both of which I've done but it has made no difference. The health metrics, HRV, breathing rate and O2 are all over the place too! My graphs look like a rugged mountain range! Stress management graphs also seem to have a mind of their own. Considering this device is nearly £300 it's extremely disappointing and although I've been a massive FitBit fan for 6yrs I have now lost confidence in the product. I've just swapped back to my Charge 3 to see if it really is my health/fitness that is affecting it and despite being fully charged and following the restart routine 4 times, the screen keeps going blank. It's enough to put your heart rate up! 😓 Not happy.

[Kjsluv2run]

I've found exactly the same thing. I also have an issue with the distance when I run. I've checked it with several apps and it's just not right. Before, when I had my Versa, my recorded run would be almost identical to Map My Run. Now, it's all over the place! In a six mile run, it could vary as much as .6 and the pace as much as 20 seconds per mile. (I also downloaded Runkeeper with the same issue.) That's unacceptable.

My resting heart rate (as checked with a blood pressure cuff) is no where near this high and never has been.  You can identify the exact date I started to wear the Sense just by looking at my RHR chart. It shot up several beats that very day and has been ever since. It is also extremely erratic.

I keep hoping a firmware update will come along and fix some of this but so far, nothing. 

As you mentioned, at $300, I'd expect better. I've had Fitbit since the Flex was first introduced (2 Flexes, 2 Charges, a Versa, and now the Sense), but now I'm thinking of trying an Apple watch instead. I'm very disappointed in this product. 

[Amelia1907]

Fitbit know about this issue, I have had my Sense since December and HR has been wildly inaccurate, particularly when exercising. I complained a few times and they said that Fitbit are aware of the issue and looking to find a fix. But no communications on it, and I got a "helpful" response from Fitbit today that said: We will do our hardest to improve how it works, but remember these are fitness devices: we never promised technical or medical accuracy or consistency. I totally understand they can't be 100% accurate, but bit of a bizarre response when they know there is an HR issue! Just so you know, they have been working on this fix since at least December so I wouldn't hold your breath on this being fixed any time soon...their previous products have been great, I'm not sure what has changed at Fitbit but this experience has put me off enough to move to either Garmin or Apple. I also think it's pretty unethical to keep selling the Sense when they know about the issue, you would have thought they would recall the product rather than sell more of them!

[Happymouse72]

Hi. Thank you for this. I am actually shocked by their response. I think launching a product in the middle of a pandemic where a rise in RHR, skin temperature and breathing rate or a drop in SpO2 could indicate that you are starting to become unwell was absolutely intentional on their part so they should have made sure it had technical accuracy. It's immoral to cash in on a desperate situation with a device that is quite frankly worthless. Even if it was bought solely  as a fitness tracker  it should be accurate! Athletes (and me!) know what their stats are so won't just accept these inaccuracies.  I too am thinking of jumping ship particularly as no one from Fitbit has commented on my post yet. Very short-sighted as I've recommended Fitbit for over 6yrs to friends and family. I just wish I hadn't spent so much money on the Sense barely 5mths ago. I feel robbed. Gutted.

[Rlewis101]

I googled "lost confidence in Fitbit metrics" to see if it is just me. I am on my third fitbit, the Versa 2 and suddenly I have an RHR of 65-67 even though during the past two years I have ramped up my strength training, cardio, solidified sleep. Oh speaking of Sleep. I now have an Apple Watch free for being in a two year study. This morning the Apple said congratulations on achieving your 7 hour sleep goal,  while Fitbit credits me with 5 hours 45 minutes.

I know when I am working intensely on the elliptical and there was a time when Fitbit recorded me as being 100% peak but this last two years it is barely above fat burn???

I am working to navigate my way around the new Apple Watch before I kiss Fitbit goodbye.

[Tgisele]

@Amelia1907 , Fitbit has known about the heartrate issue since September of 2020, and has been saying the same thing, aware of the issue.......Everyone that has complained gets the same answer. @Happymouse72 I have the exact same issues, my RHR jumped about up about 10 beats per minute and since having the Sense I have had maybe 20 minutes in the peak zone. I am giving up and just using it as a very expensive pedometer, and buying the Oura ring.  

[eezeepee]

@Rlewis101 The Apple watch does a pretty meh job in sleep tracking. It doesn't have the sleep stages breakdown so it's not able to subtract awake stage from the total time. It does do heart rate very accurately though so I give them that. The battery life definitely leaves much to be desired compared to Sense. 

[t.parker]

@eezeepeethere is a reason why some manufacturers decide not to include sleep stages into sleep tracking. The accuracy of sleep stages identification is roughly 50% (tested against PSG device). Accuracy of identification varies for different stages. Wearable technology isn't there yet to deliver a reliable breakdown of a sleep cycle. Fitbit does a good job detecting sleep epochs but sleep stages not that much (but this isn't only Fitbit problem, as I said, the technology isn't there yet).