HRV - how to interpret and use the different measurements?

Morning report shows nightly HRV which is an average. Health snapshot HRV is kind of dumb IMO but it shows live time HRV point in time. Manual HRV-specific measurement with HRM is the HRV-Stress feature. I don't truly understand this one yet but I guess it tells you your stress based on HRV, but I thought the Stress widget did the same thing so it's a bit confusing to me.

I think garmin just gives each person a lot of metrics and they do with it as they wish. I would look up on youtube some HRV videos so you can see all the different thought processes!

musicmansweden said:

My question is how do you use these different values and measurements? How to interpret "high" or "low" nightly HRV-ms, and/or high/low HRV-values in point three above?

The watch gives you 2 of the many HRV measures, all derived from the beat to beat time (RR interval) provided by some chest straps and wrist sensors: SDRR and RMSSD

5mn short term SDRR. as provided by the watch, reflects more the cardiorespiratory regulation and can be used to evaluate respiration and sleep-wake cycles. 24h long-term SDRR (not available on the watch) reflects overall cardiac health.

5mn short term RMSSD, as provided by the watch, reflects the (lack of) stress (as balance between the parasympathetic and sympathetic nervous system). It is less influenced by the respiration rate than SDRR, and more influenced by the vagal/parasympathetic nervous system. As such, it is the preferred measure to evaluate the need for rest after intensive exercises.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624990/

HRV measures are only interesting in trends for the individual. There is no point trying to interpret "high" or "low" nightly HRV data. This is why Garmin takes it a couple of level higher, with a long-term trend (HRV base) and a shorter term trend (7d average). Before Garmin provided that, users would use the HRV stress app to capture the values manually and observe trends manually.

HRV measures are highly sensitive to movement. Hence the measurements at night, or during dedicated sessions (health snapshot or HRV stress app).

I recommend you only pay attention to your HRV status. Temporary low unbalanced HRV should not worry you too much if you are following an intensive training program. Such stress is a natural response to your training. Low HRV is not always bad and might not affect your performance negatively. Vice-versa high HRV doesn't always mean "good" and might just reflect your bouncing back from a high stress period.

https://simplifaster.com/articles/interpreting-hrv-trends-athletes/

Multiple studies have shown the benefit of using RMSSD indicators to schedule intensive training blocks, but not with a drastic advantage over traditional block training

https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-115122

Being sensitive to movement means if someone fidgets a lot, HRV could really be negative correct?

Josh said:

HRV could really be negative correct?

Not possible.

But if HRV is really sensitive to movement and i fidget for example and shake my hands a lot for example, wouldn’t that cause HRV to be worse?

Josh said:

But if HRV is really sensitive to movement and i fidget for example and shake my hands a lot for example, wouldn’t that cause HRV to be worse

In a medical context, to evaluate cardiac health, risks, etc., the protocols of HRV collection require a resting period of 15mn, a specific position (sitting or supine) and the absence of personnel movement, etc.  This is how sensitive HRV is.

This is why we don't care about "real-time" values of HRV.

During exercise, HRV varies enormously and decreases very fast, even at a tiny fraction of VO2max, before it plateaus off when "moderate" exercise is reached.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5447093/

Because of this sensitivity, and thanks to processing models, we can use it to evaluate the training metrics like lactate threshold, VO2max, and their associated HR/pace or HR/power data points.

Thank you for this! Reading this it's interesting that your HRV is read overnight with the average taken as your overnight HRV (while you're mostly asleep) but the HRV Stress activity asks that you stand up and stand still for 2 minutes. I know thi is because standing is a small load on your system. So I guess to add to this guys original question, what is the purpose of the HRV Stress activity vs the normal stress glance? Wouldn't they result in the same thing, with the stress glance probably being more of a smoothed out average?