How accurate is HRV?

[SunsetRunner]

How accurate is the HRV in the health metrics?

Moderator edit: updated subject for clarity

[Shelly0872]

For sure

Sent from my iPhone

[Bangkokrunner]

The Fitbit app in terms of HRV is nonsense and a pure sales pusher. Fitbit is able to monitor these 13 pages but unable to make a clear statement about this failure. Shame on you, fitbit. You play with our health in a bad manner with your false health figures. I am out here.

[Allen57]

They are very misleading.

[Shelly0872]

Shame Fitbit
I’m going to iPhone

Sent from my iPhone

[Allen57]

The apple watch is the best
Unfortunately I am did not know until I got Fitbit. I followed the app
advice and now need surgery on my foot from over exercise

[SunsetRunner]

@Parkersspace. Thank you for the link to the Fitbit study review article.

However, your comment about Fitbit being more accurate than Apple is misleading, as this WHOLE THREAD is about Fitbit’s unreliable HRV readings.

NOTHING mentioned in the study about Fitbit HRV. 
Only looked at Steps, Energy Expenditure, Sleep time.

[Shelly0872]

It’s not misleading SIR !!!!!
I had a echocardiogram and I wore I heart monitor bc of the incorrect readings on Fitbit
I’ve worn Fitbit for 12 years
Y’all don’t care about wrong readings
Apple Watch is the best unless you have a watch like the apple that I haven’t found
If you do please direct me to it please !!!

Sent from my iPhone

[Allen57]

I never said Fitbit was better than apple. I said every review says apple
is better.


My question was did other people have hrv issues with Fitbit being
inaccurate. I believe mine are. My husband is sometime 4 hrv so I guess he
would be dead.
I have no idea where you got I said Fitbit was better. My regret is
trusting Fitbit because I think it's very inaccurate.
The hrv and the daily steps are both wrong. I have had 1200 steps register
when I was ironing and doing dishes.
I don't know how I even got on this where I keep getting messages.
But I promise you I never said or believe Fitbit is accurate and certainty
never said better than apple. That would have been me not checking auto
correct of that is true.I just made a comment now I get emails from folks
like yourself.
I am disappointed with Fitbit and Google pixel watch. Both are awful and do
not work well together.
So in closing I think Fitbit is a joke with the HRV and steps. And the
Google pixel watch with Fitbit is the worst mistake I have ever made as far
as trusting and buying a expensive watch.
I am certainly dropping Fitbit premium.
Thank you
Allen grizzard

[Allen57]

I have no idea what you are talking about.
I made a comment I did not trust Fitbit accuracy now I am getting messages
like this.

[Tlinlo7don]

I started this thread awhile ago, with just the simple question about the
accuracy. I feel that we will never hear a response from fitbit and
everyone hear pretty much has a similar issue. I'm going to drop off this
subject and wish everyone a happy holiday season and stay healthy. Thank
you.

[Shelly0872]

Merry Christmas 🎄 it’ll all work out …


Sent from my iPhone

[JamoC]

So....Glad.... I.... Found... This.....

Lol.

[Lifedancing1]

I think we all know by now that capturing a correct HRV is not really possible with this tool. All we can do is understand that it's all relative. What matters is any big change. I believe that's true, mine doesn't change much it goes up a few points and down a few points based on my lifestyle habits. I think to get an accurate HIV you have to be hooked up to machines and capture detailed data from all times of the day, not just sleeping.

[Shelly0872]

♥️

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[t.parker]

I made a small comparison of overnight HRV from two different devices (Garmin Fenix 7 and Fitbit Sense 2). Despite values being slightly different (the yellow line shows the difference), the overall HRV trend is very similar. The biggest difference however is the personal range area which for Fitbit is kept much wider. For the last 4 weeks, I had only one record of being below my personal range while it happened several times on Garmin (and aligned pretty well with my being ill). As for accuracy - this really depends on the data set (time domain and values) as well as on the calculation method so it's impossible to compare the accuracy of any of those readings without analysing a vast amount of R-R intervals (and there's no way to retrieve that). Visually, both readings seem to follow a very similar trend. That makes me assume that overnight HRV data is probably accurate enough for the purpose its being used.

I don't pay much attention to HRV but this result is actually not too bad if HRV is considered relative rather than absolute. The only thing I would adjust is the personal range size and presentation (the range is unified for the entire visible chart regardless of the time domain).

[SallyOz]

The sleep data on Charge 5 is good. No wrist wearable can capture all the metrics to do accurate HRV. Not Apple, not Garmin. Each have their own algorithms based on what data they can capture. 
Charge 5 is poor. With my readings being between 10 and 19 (that seem to be directly tied to my sleep patterns and heart rate) I knew it was wrong.
I bought an ECG grade chest strap and get consistent readings of 53 and 57. I can also get a reading of the balance between PSNS and SNS. 
I recommend you use your Fitbit for what it’s good at - monitoring sleep and exercise - and buy a chest strap if accurate HRV is important to you. It collects data points from your heart. You can’t do that with your Fitbit. You can pair a chest strap with the free eHRV app. There is also good HRV info on their site. 

[SallyOz]

correct

[SallyOz]

Wrist devices all use similar algorithms. T.Parker posted graphs from different devices all nesting into each other. They factor in length of sleep and percentage of sleeping heart rate below resting heart rate. Wrist devices can’t capture the metrics required to give an accurate HRV. 
Fitbit gives me HRV of between 12 and 23 depending on sleep and heart rate. My ECG grade chest strap averages 56. 

I had a heavy NYE and had a long sleep with low heart rate and got my highest HRV score (37) from Fitbit and my readiness score said excellent. 
My chest strap gave me my lowest score ever (50) and told me my SNS (stress) was high and gave me my lowest readiness score ever. 
I feel terrible. I believe my H10 chest strap. 
I tried to post screen shots but they were rejected 

[Shelly0872]

Yep

Sent from my iPhone

[SallyOz]

Fitbit (blue) HRV vs ECG grade chest strap (orange) HRV. No correlation whatsoever.

readings taken on the same day at the same time on the same person.  The morning HRV reading from Fitbit and the reading from an ECG grade chest strap 15 minutes later.