Why Does HRV Require a Chest Strap?

Yes I agree. One hrv reading per day at a set time, which for some reason you cannot do with a garmin watch without a chest strap, and even with a chest strap you just get one stupid number with no context. No rmssd, no sdnn, no frequency, no nothing. 

And today I saw this and began to realize garmin may in fact have no idea how to innovate and keep up with fitness tech advances. Good thing they bought first beat or they'd be in serious trouble

"Apple Watch blood sugar sensor 'coming in Series 7' – report - 9to5Mac" 9to5mac-com.cdn.ampproject.org/.../

the5krunner said:

SDNN and rMSSD are not patented.

Of course they're not. They are used for statistical analysis of the measured data _ SDNN = standard deviation of the N to N  interval; rMSSD = Root Mean Squared of the Standard Deviation.

Like a lot of numbers Garmin throw out it's up to us users to learn to understand their relevance. Unfortunate some people just collect the numbers without understanding what they are and how they might or might not reflect on performance.

Skyewalkr said:

"Apple Watch blood sugar sensor 'coming in Series 7' – report - 9to5Mac" 9to5mac-com.cdn.ampproject.org/.../

But will it be any use? Would any diabetic trust their life to the number? Apple, and others, can produce all the numbers they want but that does no mean the numbers are any use.

hey it looks like someone else noticed the same ridiculousness that i did

gadgetsandwearables.com/.../

I’m sure there are many more too who do not understand the difference between ‘measured’ and ‘estimated’.

GARMIN’s approach is to give you accurate HRV data measured from the strap. Under normal conditions HRV is measured with the participant lying down and resting so GARMIN is following what would be termed ‘correct’ procedure. Moving around during HRV testing is likely to induce artifacts that would affect the data.

Since the majority of people who post here complain about data accuracy these same people should give GARMIN credit for doing what they can to provide accurately measured data not possibly accurate estimated data.

In response to the body position while doing the test:

Garmin asks you to be standing for the 3 minutes of the test. I know other devices require you to sit down and lean back. Yet others ask you to lay down.

I wonder what is actually the best of the three options?

For my research we had people lying down in a darkened room for 5 minutes.

I think it doesn’t matter too much as long as you take the measurement in the same way each time, and remain still for the duration. Sitting or lying down will likely offer the best chance of remaining still.

Understood. I was measuring it standing up, but your point makes a lot of sense and I will start doing it sitting from tormorrow morning on. Thanks.

since the original post i've been doing a TON of research. i must say, that guy mentioned earlier, marco altini, really does seem to know what he's doing. he says that standing, sitting, lying down, it doesn't matter, as long as you're consistent:

Measurement time and position: try to measure always in the same body position, normally I recommend simply lying down in bed, as that’s the easiest for most people. The alarm goes off, wait a minute, then take the measurement while still lying in bed. If this is not possible (e.g. you have kids jumping on you), it’s perfectly fine to have a slightly different routine, for example going to the bathroom, sitting there and measuring. The important bit is to try to do it, in the same way, each morning.

basically, i've come to the conclusion that garmin's treatment of hrv as it pertains to us the end users is utter nonsense. you do not need a strap, you do not need to be standing for 3 minutes and you should have access to the data. garmin disagrees, so i've moved on. altini's group has a site and app called hrv4training which i'm trying out and seems to fit the bill rather nicely. the only problem of course is that it's not part of the garmin ecosystem. so it can read hrv data from apple watch and oura, whoop etc. but not garmin, because...garmin