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AF Association
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Fitbit heart rate all over the place - is it ectopics?

On a recent walk, at a steady pace, I noticed my fitbit was recording my pulse rate as >160. This seemed really odd as, while my pulse was going at a decent rate, it was no way near these kinds of numbers. This has happened a number of times and I'm wondering what the reason could be.

I've come up with the following options:

1. Ectopics - even if I haven't noticed them, could these have been confusing the Fitbit such that it records a much higher pulse rate?

2. Short runs of AF (would I not have noticed?)

3. Short runs of ventricular tachycardia (would I not feel this?)

I'm a bit perplexed as I haven't felt anything wrong while walking, but since my cardiologist recommended that I keep my heart/pulse rate low (ideally below 110bpm) I'd like to know whether others have experienced dodgy pulse rate monitoring by their fitbits and if they have worked out the cause.

Thanks in advance,

Pete (Pikaia)

7 Replies

Sorry to tell you but Fitbit HR is a waste of time. I gave up using mine as it was wildly wrong, especially when in exercise mode. I wore my Mio HR strap along side and confirmed Fitbit is very poor. I actually think Fitbit use movement detection as an input (cheat) to their HR algorithm - when I walk anywhere, my HR would go up to 120, in reality is was 80.

Now yes, there is a possibility the ectopics are confusing the Fitbit, but they don't confuse my Mio, hence I completely lost trust in Fitbit.

1 like

I'm inclined to agree with you. It can be wildly inaccurate, and I was wondering if that was ectopics, but from what you've written it sounds like you think it's just the Fitbit not being very good.

So the Mio is a better choice by the sounds of it.


I've not used a Fitbit but have compared my exercise HR monitor (with chest sensor) to a blood oxygen meter (that also measures pulse with light), which I suspect may work on the same lines as a Fitbit. And yes, there was a great difference in reading when I'm in AF.....no resemblance at all.

I've been relying on my exercise monitor during episodes of AF for a long time and it has been very reliable. However, recently during an episode the readings got lower and lower, which is unusual in my AF. When it reached just 50 I called my daughter to take me to A&E but she was away for the weekend. When it dropped to 46 I phoned for the ambulance and whilst on the phone it got down to 40. Panic stations!!!! The ambo's arrived in 10 minutes and wired me up. Yes, I was in AF but with a pulse varying from 80 to 120 bpm......and yes, my very reliable monitor had gone wrong.

So I'm not sure what to suggest to you, like humans these gadgets seem fallible.

Let us know what replaces your Fitbit and how well it works. I've ordered a watch which senses electric pulses, so quite new technology. But it's cheap and I thought why not give it a try as it also does many of the functions that a Kardia unit does including downloadable traces. One thing for sure though, I won't be relying on it.



I have a fitbit and have noticed big differences in heart rate between that and even the gym equipment monitors so i would not put too much confidence in one...


Fitbit is as much use as a chocolate teapot - to prove it take a simple finger monitor and compare it - it beggars belief that fit bit is SO poor at HRM

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I am fitted with a dual chamber pacemaker. This of course records the activity of my heart over time. When I last had it checked I was told that I am in more or less permanent AF although the rate seldom exceeds 80 to 90 bpm. The interesting thing is I am not aware of any irregularities and taken at my wrist my pulse is seldom more than 72. My consultant does not appear concerned and is quite happy to leave things as they are unless my quality of life becomes severely affected. In which case he is likely to recommend an AV node ablation and a different pacemaker. In the meantime I will continue on the vital anti coagulant tablets. I did stop taking amioderone a couple of years ago and have not replaced it with any other drug.



Fitbit is HIGHLY unreliable. I know I own one.


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