Garmin HRV Data
Heart Rate Variability (HRV) is a very important measurement for health and recovery. For quite a few years now, Garmin has been providing this in the sense of "stress", where the higher the HRV, the lower the stress and vice-versa.
This form of representing HRV has its ups and downs. On the one hand, it provides an already interpreted value of HRV to allow the user or developers to simply use it without analysis. On the other hand, the user now loses the ability to see trends in HRV, or the developer might not be able to perform their own interpretations of the HRV data.
However, all of this is now behind us. Garmin has officially been dishing out raw HRV data, not only in the Garmin Connect App but also as part of their HEALTH API!
The Data
If you have any of the more recent Garmin watches (Fenix 6,7, EPIX 2, Forerunner 955 and 255, Enduro, MARQ), you would be able to see the new HRV graphs for your sleep sessions.
The data within these graphs are given at a 5-minute interval. This is also true for the data retrieved from their HEALTH API.
Here is an example:
From the data above, you can easily parse it and interpret it however you wish in your app! However, these are given separately from that of sleep data. If you want to get the whole overview of the sleep session, you would also have to request this separately...
Integration
Being Terra, we jumped on it as soon as we found out about this! A lot of our developers have been asking for this since the day we released our Garmin integration. So to make everything easier, we have added HRV samples as part of our sleep payloads. You can start taking the samples directly from the payload in your app and not have to worry about requesting for both sleep and HRV data separately from Garmin: