HRV (RMSSD) results in Health Snapshot are useless

Are you trolling? 50 and 42 is excellent. What are you talking about ?

You guys are elite athletes! See here

HRV is a really interesting subject. I would read up on in/watch youtube videos before you say that. There's a lot of factors that go into it.

Some more good info: https://elitehrv.com/normal-heart-rate-variability-age-gender 

Ppiioottrr said:

Garmin says that values above 100ms are OK, 50-100 problematic, and below 50 - mortal condition

Could you please share a link to your source?

Ppiioottrr said:

My reads were below 50 , even before 40 - I am still alive and fine. I tested the reads on my (very healthy wife) - she got 42.

There is no point comparing short-term epoch rMSSD values to other people. This is meaningless. However, for long-term epoch (typically 24h) rMSSD values, studies point to correlation with certain general respiratory, cardiac and risks (eg pre- and post-operatory risks conditions), and therefore some general population trends have been identified for benchmarking.

Garmin watches gives short-term epoch rMSSD (typically 5mn). This range has proven useful to use when training, in particular to identify recovery time after intensive training.

The correct way to use these values is to see them in trends.

Generally, a decreasing HRV indicates stress. This can just be a reflection of the good stress your training is putting on your body, or it can be a bad trend due to disease, injury, alcohol, emotional stress etc. Note that your can reach excellent to top level of performance with a much lower than ususal HRV.

Generally, increase HRV indicates less stress. This can be a reflection of recovery or benefits acquired from lower intensity training.

Finally, your statements have nothing to do with the usefulness of the health snapshot rMSSD values, but how you thought you should/could interpret them, in the context of the Garmin benchmarks.

Garmin says no such thing.

Garmin referenced to this page: https://blog.mymetabolicmeals.com/hrv-guide/

https://forums.garmin.com/sports-fitness/healthandwellness/f/venu-2/283232/garmin-health-snapshot---hrv-reliability-and-accuracy - I found that post quite interesting and I guess it applies not justvtovenu but to epix and any other garmni's device providing hrv

Not acording to this: blog.mymetabolicmeals.com/.../

are you trolling ?

Ppiioottrr said:

Garmin referenced to this page: https://blog.mymetabolicmeals.com/hrv-guide/

Where does Garmin makes a reference to this page?

This is not a Garmin page.

The article makes a decent effort to introduce readers to HRV, but does not mention where its benchmarks for good and bad HRV come from, or what measure they use. So, this is totally irrelevant to your statement in your initial post.

It does make a reference to the the EliteHRV web page, that features some analysis of its users, not the general population. So, again irrelevant to your statement in your initial post.

The EliteHRV page says:

"Ideally though, instead of using others’ HRV scores for comparison, you should begin to monitor your HRV scores regularly and look for upward trends as you incorporate positive changes into your lifestyle."

https://elitehrv.com/what-is-heart-rate-variability

Ppiioottrr said:

https://forums.garmin.com/sports-fitness/healthandwellness/f/venu-2/283232/garmin-health-snapshot---hrv-reliability-and-accuracy - I found that post quite interesting and I guess it applies not justvtovenu but to epix and any other garmni's device providing hrv

Maybe, maybe not. For sure, comparing a wrist-based PPG sensor to a chest-strap capable of sending RR data, or to software capable of processing HR into RR is going to show the well known challenges of wrist-based PPG for HRV measurement. Garmin/Firstbeat is acknowledging this and this is why HRV metrics are measured during rest  and  why Garmin is now supporting chest straps for the health-snapshot.

While the analysis is well documented, there are some significant challenges:

- you cannot compare SDNN and SDRR values, there are not the same measure.

- you cannot compare rMSSD across different epochs. Apparently HRV4training is using a 60s epoch. Apparently, Garmin is using a 2mn (?) for Snapshot, 3mn (?) for HRV stress and 5mn (?) for night HRV. Not the same epochs, not the same values.

More worrisome is that this Garmin user found a low correlation between the Garmin HRV metrics and the EliteHRV or HRV4training metrics. This should not be the case. Although using different epochs (rMSSD) or different data points (SDNN vs SDRR), the pairs should be highly correlated and they are not ( r ~0.2). Not a great showing for wrist-based HRV accuracy, but this is not news.

If you want to leverage HRV metrics best, a good VO2 evaluation, a good threshold test, use a chest-strap that sends RR intervals.

If you want to measure HRV metrics accurately, use ECG, a chest-strap or a medical grade PPG device, and desktop software for correction, processing and analysis.

Still,  I am not sure where you are going with your posts, and where your initial post is coming from...