HRV sleep values vs HRM belt plus Elite HRV app

mikekoski490

I was a bit concerned last few weeks with my SR overnight HRV scores. They kept reading 15 to 17. This typically would mean I’m in a state of constant stress, even though my other indicators (sleep score/resoureces/recovery /resting hrm 48/workout hr etc) are all good.

I ‘feel’ I should be in the 50 to 60 range based on articles written on HRV. 15 would indicate serious illness or something.

In doing some research, and since I use an HRM (Suunto but have a Polar h10 on the way) I found a review on an app that uses an HRM belt called Elite HRV, and the app pairs to your Bluetooth belt via your cellphone.

Ive been using it paired with my HRM and values are, over a 24 hour period and 3 tests, between 55 and 66. This is a normal range score for my fitness and age.

I have to say that the Suunto HRV seems way off in my case, so much so it was a bit disconcerting to me but glad I’ve found a alternative.

Interested to hear from others with an HRM belt if they have tried the app and see different or similar HRV scores?

Mauerwegler

@mikekoski490 This is apparently a complicated topic. Have a look at https://the5krunner.com/2022/01/11/hrv-more-than-you-ever-needed-or-wanted-to-know/

I have read some of the linked blog posts a while ago and found them very interesting.

tiago

@mikekoski490 probably you are facing some software bug or the sensor have some trouble to do the HRV readings. I sleep with the Race on left wrist and Fênix 7 solar in right wrist and normally they agree in the values,some times the same value, others a difference of+/- 2 or 3 ms. Before I bought the Suunto i tried with the 955 and Fênix 7 and the readings are similar, so I don’t find issues in HRV readings. I think is like the accuracy of heart rate,works well for ones, don’t work well for others,and that can be many factors affecting. My baseline on Garmin is between 71 and 99 and 7 days average 73 ms ,in Suunto race,I don’t have the 14 nights, because I’m a night shift worker and sometimes the Suunto Race count my sleep during the day as a nap and don’t give me HRV readings,I think tomorrow will make the 14 nights of sleep,but my 7 days average on Suunto is 74 ms,so for me seems spot on

mikekoski490

@Mauerwegler Thanks! I think I do understand HRV. What I was surprised with is generally Suunto has good recovery and OHR sleeping metrics, but huge discrepancy between overnight HRV on Suunto (15 HRV score), and my Polar H10 with Elite HRV app (55 to 67).

Mauerwegler

@mikekoski490 The HRV topic has come up again, especially comparing to the Elite HRV app. See https://forum.suunto.com/topic/10018/hrv-overnight-readings-thoughts/

larrybbaker

I see issues also between what the Vertical reports and what I get through Elite HRV and Apple Watch using SleepWatch app.

SV reports any where from low 20s to a high of 42-45 once or twice. 7 day average of 28.
Elite HRV and Sleepwatch app [AW series 8] are consistently in the 50s for HRV.

I believe I read soemthwere that Suunto only looks at the first 4 hours of sleep? Is that correct?
The SleepWatch app appears to monitor it over night.
Elite HRV uses the morning readiness a 2.5 minute test but random reading I have done over the course of a day always are similar - in the 50s.

Sensor/Suunto algorithm issues or?

Swaddy61

@larrybbaker As said above, this has been discussed in the other thread. The summary was that even the units for Elite and Suunto are different, so you are comparing apples with oranges!

I think it is more important to follow the trends - i.e. if you get a reading above or below your norm on Suunto, then you should be a little more cautious, rather than looking at, and comparing, an absolute value with a different measurement system from, e.g. Elite.

I also use Elite and Suunto. Usually, but not always, if I have an out of norm reading on one, then I will on the other - regardless of the actual absolute values.

larrybbaker

@Swaddy61 Thanks! kind of what I have been doing - just had not seen this discussion before.

mikekoski490

@larrybbaker Seems like there are quite a few ways to get an HRV score, so yes making sure you are watching trends over the raw number is the way to go. My Suunto and Elite HRV trends always match. Below are what I found on the web for all the difference ways to measure HRV:

Parameter Unit Description
SDNN ms Standard deviation of NN intervals
SDRR ms Standard deviation of RR intervals
SDANN ms Standard deviation of the average NN intervals for each 5 min segment of a 24 h HRV recording
SDNN index (SDNNI) ms Mean of the standard deviations of all the NN intervals for each 5 min segment of a 24 h HRV recording
pNN50 % Percentage of successive RR intervals that differ by more than 50 ms
HR Max − HR Min bpm Average difference between the highest and lowest heart rates during each respiratory cycle
RMSSD ms Root mean square of successive RR interval differences
HRV triangular index Integral of the density of the RR interval histogram divided by its height
TINN ms Baseline width of the RR interval histogram

fabula670

A note of mine about my actual experience with HRV:

just after resetting the watch (due to calibration issues - there’s a topic by me, btw.) my HRV range has experienced some inconsistency, as the watch shows that the normal range is 26-30 while in the app has remained the previous one (23-27).
after a bit more than a week, watch shows always the same but app shows 23-28.