Inspire HR Heart rate variability

[kmgiuliano23]

So, heart rate variability just popped up in my FitBit App. I clicked it the first day and it didn’t have data yet. So I slept, and in the morning my variability was 26 milliseconds. My RHR is about 62 on average. I have a healthy heart.

I didn’t know much about HRV so I googled it and I’m finding the average is in the 60s - like it’s similar to your RHR since it’s milliseconds between beats. Having 26/27ms would mean my heart is not working well at all.

Am I missing something? Or is my FitBit likely wrong? 

Moderator Edit: Clarified subject

[LZeeW]

Hello @kmgiuliano23 and welcome to the Help forums.  Did you tap on the Learn More option in the app?  There is a brief paragraph that talks about HRV differences between people.  Stress is a big factor and can lower your HRV.  I think you will find some helpful information.  I don't think you should be overly concerned about one day's value without knowing the full story.

HRV is not similar to your RHR.  The formula that is used is the RMSSD.  That stands for Root Mean Square of the Successive Differences.  Quite a mouthful, don't you think?

[kmgiuliano23]

Hi! 

But what confuses me is that it’s while I’m sleeping. So, I don’t think stress is a factor...and nothing else about me “stands out” to make it so low.

Also, just FYI I had a second night tracked and it was pretty much the same - I think raised by one.

it just seems really bizarre because my vitals are always very normal. And I feel like my heart rate couldn’t be 60 if my HRV was 27ish. How is that even possible? I feel like with a HRV of 27, you would have a fast heart rate, no?

[SunsetRunner]

I am having this happen too! And the more info thing isn’t very helpful.

[kmgiuliano23]

Yeah I don’t know! I’m going to ask my doctor just to be safe.

[claudeVig]

Consider that Fitbit measure this in Millisecond and not in %. THere is many information about %HRV that does not apply to our numbers in milliseconds. Mine is 25ms on a Sense that very different to 25% HRV. In my case it is lower that my age group, which is ideal. 

This is the best documentation I found about ms HRV: https://www.whoop.com/thelocker/heart-rate-variability-hrv/

[SunsetRunner]

Hi everyone,

I just signed up for the free Premium test drive and am curious about the HRV measurement too. I'm in a similar demographic - age 59, male and RHR usually 60 or so. Cardio fitness Very Good to Excellent for men my age according to the app but HRV around 25msec or so.

Thanks claudVig for that link - very informative.

That said, I'm still not fully getting it. I think I understand the idea of what HRV is assessing - when I was a kid I could be watching cartoons (for example) with a low RHR but if I heard the ice cream truck bell, I'd be sprinting out the door in a heartbeat (sorry!) and my younger self would have demonstrated pretty impressive heart rate variability.

Echoing kmguiliano23's thought - if Fitbit measure HRV while sleeping, this seems to me to be measuring variance at a "no load" situation, kind of like measuring a trucks power output on a dynamometer except it's a idle.

Not disputing anything anyone cares to post, just trying to learn.

TIA,

Probably shouldn't have included age or gender when I said "demographic".  No offense kmguiliano23 - just saw your profile photo.

Moderator edit: merged reply

[Barryone]

I agree, I also miss a comparison chart of somewhat like with the condition tab (VO2 max). Of course this is a bit more complicated and probably Fitbit decided not to include a chart because of... reasons, maybe because the story is, “it changes from day to day and you are your own benchmark”, but generally the Fitbit users are not doctors so need a bit more guiding with the info they’re presented with. 

[debkish]

Mine too, mine popped up and was 17 for 2 days, then 36 for the last three days. 65 heart rate, and 5-7 miles run/ walk everyday.  40 years old  and healthy. Very strange ge but concerned.

[Micsb]

HRV is the variations, not the absolute time between each heart beat. If HRV is 0, the time between each heartbeat would be exactly the same. The body will constantly throttle the HR up or down when additional oxygen is needed etc.

A large HRV means the system is working great at quickly adjusting HR as needed. 

For comparison it must be measured under the same conditions each time as the HRV will change significantly during exercises, where it can drop down to 2-3ms. For this reason I guess Fitbit decided to measure during sleep only. HRV is affected by stress and fatigue.

I used to run a lot years ago and had a watch that could display HRV in realtime. When completely restituted the HRV was higher and quick to increase HR when I started out running. When exausted the HRV would be lower and it took longer for the HR to increase and match the running intensity.

As I understand the study of HRV is still quite new, and it can be difficult to say if 28ms is good or bad. The important part is rather the changes from day to day that will show if you are restitued and ready for a high intensity exercise or exhaused and stressed and need to take it easy a couple of days.

[Barryone]

Aha, this makes sense, thank you

[KimKav]

My HRV is consistently under 20. Usually 14-16. My cardiac fitness score says I'm in "very good to excellent" shape. I do a 5K a day. Doctor did an echo and holter and found nothing wrong. I'm really questioning the accuracy.

[SunsetRunner]

I think it is completely unreliable I have a polar h10 chest strap that shows my hrv range to be in the 60ms area every night. I wore this along with my Fitbit versa 2 the Fitbit showed 15ms for last night while the polar chest strap shows 62ms with the calculation so it is obvious the Fitbit is just not working correctly. I am a former professional athlete in my late 40’s 6’6” 254 Ibs I work out four to five days a week as a point of reference. Annual ekg holter monitor and stress tests all test me in the “elite athlete” demographic. So if your worried try a polar chest strap that tracks HRV if it is too low then see your doctor and have your heart tested.

[judetheobscure]

I have found my tribe!

Not an elite athlete by any means but I exercise pretty much daily and have done for many years (mid 50s female if demographic is important!). My rhr is in the 50s or low 60s and I have a cardio fitness score of 43-47 which is excellent for my age. 

But my hrv is consistently in the low to mid 20s. The highest it's ever been was 44 but that was a fairly isolated incident with no obvious reasons for it. I suffer pretty much no stress and sleep very well all the time. By chance I had a 24hr ECG recently and 'passed' with flying colours. 

So I have a degree of scepticism about the relevance or usefulness of this hrv but am happy to be corrected 😬😂

[BluenoserCanuck]

Well thank goodness for this forum! I just signed up for premium and my first HRV is recorded as 15! All other readings are excellent, great RHR and in healthy and active. What a jolt to find that a 15 ms HRV can mean serious health issues. Hopefully there’s a glitch. 

[Elefunk42]

Same problem here. I'm fairly confident that I'm healthy, but my fitbit shows my HRV to be 15 pretty consistently and I find that alarming. 

[Fiona_G]

Let me add my concerns. My resting is 66 average. My HRV is consistently around 20ms (??) According to the only google link I can find -the wish link in comments above - I should be dead. Normal fro 57 ( my age) starts at 30ms. The Fitbit info is wholly inadequate. 

I should add that on my versa 2 the Sp02 data works 50% of the time. No data is common fate. For $100.00 a year they should do better. 

the HRV info is inadequate at best.

The learn more say nothing but a higher HRV is good. Is high 20 or 80? You need a bench mark or more detail. According to the whoosh article in google most of us should be dead. Nobody here is reporting more than 30ms a night and in my age group normal starts at 30ms on the wioosh article. We need more info! Yesterday! Put a disclaimer if you must but publish some useful data. 

Moderator edit: merged reply

[Jeroen77]

I wonder if people only end up in this thread because they are concerned 😅
I did, just googling what my 31 ms actually meant. All my other stats have no reason for concern. Good sleep, 55 bpm, 56 fitness score.

[SandyRocks]

This is a great thread I've fallen into!

I've just been using my new Versa3 after years with the Charge 2, and moved specifically to take advantage of the HRV feature as I'm over 60 and worried about AF. But now trying to work out what it's telling me. I'm a bit worried now that all on this thread are reporting HRV of less than 30ms, whereas mine are around 60ms! Yet my My RHR is normally between 43 and 47, I run almost every day, my cardio fitness is 55, Good-excellent sleep .. so what's the story? Maybe the "inventors" of this feature are simply saying that its the Variability of the HRV that counts? Variability of the variable ..ha!

[SeanFeb]

I think the inspire 2 HRV is total garbage also. First of all it only checks at night. What is with that?  I am 58. RHR around 58 to 60. Workout every day. BMI around 23.   Highly stressed and anxious but this HRV thing is way off. I have found online literature saying HRV for fitbit is totally useless so I deleted it. Mine swings between 25 and 40. Total garbage