Which HRV calculation model does Garmin use?

Training
1

Hello everyone,

can anyone tell me which calculation model Garmin (1040) uses for the HRV?
I couldn’t find any information, and I don’t know whether I should enter HRV (rMSSD) or HRV (sDNN) under Intervals (Wellness Card).

HRV

Best regards
Andrea

1 Like
2

It’s rMSSD, the industry standard.

3

Thank you very much :slight_smile:

4

Only Apple uses the other one, SDNN, afaik.

5

Here’s a more detailed explanation on the different uses of rMSSD and SDNN. It’s an AI generated answer, and not my own words.

rMSSD (Root Mean Square of Successive Differences) is used for short-term HRV analysis, focusing on rapid fluctuations and parasympathetic activity, while SDNN (Standard Deviation of Normal-to-Normal Intervals) is better for long-term HRV trends, assessing overall cardiovascular health and both sympathetic and parasympathetic activity

  • rMSSD:

    • Measures the variability between consecutive heartbeats, reflecting beat-to-beat fluctuations.
    • Primarily reflects parasympathetic activity, which is responsible for “rest and digest” functions.
    • Useful for assessing immediate recovery, readiness for training, and short-term stress responses.
    • Good for short-term HRV monitoring, like during exercise or stress testing.

  • SDNN:

    • Measures the standard deviation of all normal-to-normal R-R intervals (the time between heartbeats).
    • Reflects overall HRV, influenced by both short-term and long-term variability, and both sympathetic and parasympathetic activity.
    • Useful for tracking long-term trends in cardiovascular health, overall stress levels, and chronic training load.
    • Often used for long-term HRV monitoring, like overnight or over several days.
    • Considered the clinical gold standard for assessing cardiovascular health over a 24-hour period.

The last point is important, as SDNN should be measure over a longer period compared to rMSSD.

6

You are imputing manually? You can connect Garmin and enable the sync automatically.

7

I have just checked.

I measured the HRV value on my 1040 for the first time today.
The check mark is set.
Maybe it will transfer the value automatically tomorrow.

1 Like
8

It updates the values after your nomal rest/sleeping time(set in garmin) in the morning since these are technically night values from watches not a cyclingheadunit