HRV in Watch series 3

Just learned in another thread on reddit that HRV in Apple Watch is measured automatically thought the day (not sure when/trigger) or when you run the Breath App exercise. Interesting ly enough i tested the breath app and now HRV values see pretty good , increased from 20ms to 89ms. Higher HRV seems to be a desirable thing.

I’m running Apple Watch 3 with Watch OS4 and activity app reports HRV, what I’m not sure is the accuracy of it. The values are very low anyway not exactly sure what’s really expected , also read some blogs claiming that photometry methods of Apple Watch aren’t accurate enough for HRV type of measurements...

Hi

Apple has not stated that Apple Watch Series 3 measures HRV.

It seems to be very accurate. I even tested it by doing a round of breathing to see what HRV I got. I got 95. Then I ran the breath app without paying attention to it and got a 22. Your breathing actually does play a part in your HRV. And your watch is accurate enough to tell.

According to this link they do. I have highlighted in bold.

Your heart rate. What it means, and where on Apple Watch you’ll find it. - Apple Support

"Apple Watch uses green LED lights to measure your heart rate during workouts and Breathe sessions, and to calculate walking average and Heart Rate Variability (HRV)."

Heart-rate variability tracking. This stat can be used to understand how well you’re recovering and if you’re about to get sick. The Watch measures this when you initiate the Breatheapp (Apple's mindfulness tool) and during other times the Watch detects to be suitable throughout the day.

Apple usually doesn't lie or provide ****** products, so it should work. Maybe not as accurate as some people would like but would probably give good approximations.

If anyone could disprove me I would be glad.

My reply was accurate at the time of posting (before the release of watchOS 4 and iOS 11).

So, what does it all mean. That you should be careful when to measure HRV with the watch? I don't know when it measures HRV or if it is done manually or automatically.

Indeed, with proper breathing HRV looks good , ranging between 80 and 107 for me. When AppleWatch on it's own decides to pick HRV without me paying attention then HRV values are much lower - 20s 30s range. Didn't know breathing was that relevant for HRV computation, but if that's so then is good to learn something new.

Thanks