How accurate is HRV?

[SunsetRunner]

How accurate is the HRV in the health metrics?

Moderator edit: updated subject for clarity

[eltoo]

It seems from what I've read online that overtraining and over-exertion, and the associated fatigue, lowers HRV, until the body has had sufficient time to recover.  So even very fit people who overdo it regularly can have low or declining HRV, notwithstanding their level of fitness.      

[hannakopo]

I most definitely do not over train. I work out a few times a week and would consider myself to have a slightly above average fitness level. There is no way a reading should be so inaccurate, especially if literally hundreds of people in this thread are claiming the same. It’s not just searching random symptoms and going down a Google rabbit hole, the range that most people are getting here is described as being a precursor for “catastrophic illness, or death”. I get having readings that are not entirely accurate, but this seems like a major flaw with the device. They should not have the reading if it is THIS inaccurate.

[eltoo]

I agree.  I started using the EliteHRV free app (and a polar heart strap) and have been taking morning readings as suggested.  Those readings seem much more consistent and a bit closer to my own sense of where I should be, but it's still early days.  And, I suppose it's fair to add that for some folks (certainly me included) our self awareness of our level of fitness may be more accurate and more objective than our self-awareness of our baseline level of stress (anxiety; quality of sleep and recovery; quality of diet; bodily inflammation; etc), and the latter is what is manifested in HRV in ways that might be unexpected.    

[phatbitzr]

I got the old Blaze and the Health Metrics feature, including the HRV  feature just became available on my app. I noticed my HRV range is in the 13 to 21 millisecond range. At first I thought it was good because it was low, then freaked out after finding out that range was bad, then came to accept it because the app's reporting is so off the mark that I should ignore the absolute number. I ride/spin from 2-3 hours on weekdays and 4-6 hours on weekends so I wasn't expecting to have a HRV of a person that's on their death-bed.

I am still looking at the numbers and wonder if its reporting for that given day determines whether I should do an all out high intensity day, tempo pace or just do an easier recovery ride, Does that number determine how well recovered I am or am over-training, compared to other days?

I kind of looked into the Elite HRV but I have limited time in the morning before rushing out to exercise, so not sure if I could set aside time to use the app and determine my HRV

[eltoo]

I find all the data relating to HRV quite confusing.  Elite HRV gives you an HRV number, which is straightforward enough, but also provides lots of other statistics that I don't understand and haven't taken the time to study.  E-HRV also gives you a daily "readiness" score (on a scale of 1 - 10), which it presumably deduces based on all the data it collects from your 2-1/2 minute morning reading.  I don't pretend to know enough to evaluate it, but it does provide a handy single metric that ostensibly tells you whether it should be a rest/recovery or push hard day or something in-between day.  I'll share one recent experience.  I went snow skiing for 10 days and skied reasonably hard, and my morning readiness scores varied from 7-10 on those days and seemed correlated with how hard I pushed myself the previous day.  I then drove two days for about 6 - 8 hours each, and my next two AM readiness scores dropped to 2 - 3.  I was initially perplexed, since I assumed that skiing was much more demanding.  On further reflection, it seems that although skiing was physically taxing, it was fun and enjoyable; whereas (for me) driving 70+ MPH for hours on end is both exhausting and stressful.  That seems to be what the difference in the readiness scores reflected.    

[nearthound]

"Everything You Need to Know About Fitbit HRV Accuracy" 2/18/22 http://digitallifecentral.com/fitbit-hrv-accuracy-27/

[Fitnessheals]

I’m so glad I found this thread too because I know the importance of HRV and yet I can’t believe that mine is right! I’m in my 40’s and have been proactively managing my health through healthy eating and exercise since my mid-20’s. All my biomarkers are good and I’ve run a marathon but my HRV as measured on my Fitbit is so low (in the 30’s) that I’m surprised I’m not dead!

[Solutiongirl]

Ya I feel ya. I've had it 9 frequently..but now that I've lost some weight
and also doing peloton and walking it g I es from 13 to 22..still freaks me
out. I'm going to sew a specialist anyway..not due to the monitor
really..but it didn't help my security in the matter.
Any updates are welcome.

[Shelly0872]

Fitbit devises aren’t correct


Sent from my iPhone

[Shellbubs]

Same I got a new Fitbit last week and my HRV is saying 38!! I started reading up on it and apparently that’s in the range for 60 to 70 year olds. I’m 29 😂 I was panicking for a few days but relieved so see others with the same issue. 

[GinaGPC]

Thanks for raising this post. I've read through all the comments and am relieved its not just me. During covid I had all the heart tests going as they didn't quite understand what was going on and everything looked good so my hideously low fitbit hrv score completely threw me. I ended up buying a polar h10 strap and keeping tabs on it with elite hrv out of interest now and although that's daytime figures only, its much more reflective of my fitness levels!

Sort it out fitbit!! The health service doesn't need more people running to the docs based on inaccurate results! 

[Fitnessheals]

Thank you for sharing your experience. It's reassuring because my low HRV
through Fitbit was creating more stress! I may try the strap you bought too
out of curiosity to double check. I'm glad you have a better measurement
now that's in line with your fitness level!

[Shelly0872]

Thank you

Sent from my iPhone

[Felitsa]

Same here! Only 13ms for a while week while other data is quite normal, even good. I was starting to get deeply concerned until I started reading all these comments. Perhaps i'm not in the verge of doom after all 😉

[Solutiongirl]

Exactly! Since working out reg and eating clean I've gotten it as high as
17 🤣😭...it obvious there's a little issue since others that have
commented most are ranging 20 to 40..so its off ...but still 9 -11 still
concerns me..rather it be inaccurate between 20 to 50 ..if ya get my point.

[Keto4life]

Lol, me too 😂. I was so worried I was ready to call my doctor! Thank goodness I found this first. The more I read about these watches the more I feel like, what's the point. The functions we buy the watch for either don't work properly, are extremely inaccurate, or don't work at all. I'm afraid this (sense 2) will be my last Fitbit watch.

[Shelly0872]

Ditto me too

Sent from my iPhone

[Fitnessheals]

I don’t think any of us are as Fitbit’s HRV reading would have us believe!
In fact anyone who even cares to track their HRV is probably the type who
is health focused and in better shape than the average person. ☺️

[Waholic]

Agree thanks for posting I signed up to be able to post just because of this. I assumed low hrv would be a good thing when I read about it....thought I better run to the hospital....mine is running at 15!!!! Hope this isn't right!!!

[Fitnessheals]

I completely understand! Based on the FitBit HRV scores, a whole community
of us would be in the hospital! I’ve chosen to ignore my score but I would
like to get an accurate assessment to know where I actually stand. I’ll
post if I find more information to share!