A Garmin app that measures HRV(Heart Rate Variability) in a 3 minute test. Saves the output as a Connect IQ activity.
Link to the Garmin Connect IQ app store.
- HRV (Heart Rate Variability)
- RMSSD - Root Mean Square of Successive Differences (beat-to-beat intervals)
- pNN20 - % of successive beat-to-beat intervals that differ by more than 20 ms
- pNN50 - % of successive beat-to-beat intervals that differ by more than 50 ms
- beat-to-beat interval - reading coming directly from the watch sensor
- HRV Successive Differences - difference between current and previous beat-to-beat intervals
- SDRR - Standard Deviation of beat-to-beat intervals
- HRV RMSSD 30 Sec Window - RMSSD calculated for consecutive 30 second intervals
- HR from heartbeat - beat-to-beat interval converted to HR
- HR (Heart Rate)
- minimum
- average
- maximum
Results are saved as a Garmin Connect activity category Other named Test HRV: 
The summary data is saved under Stats, section Connect IQ:
The extra graphs are shown next to the built-in Garmin graphs:
- Connect IQ 3+ compatible device that tracks Heart Beat Interval data
- Measurements taken from the built-in optical HR sensor on the watch
- For reliable readings minimise wrist movement
- No strap required
- HR straps not supported
- The app starts measurements automatically as soon as stable sensor readings are detected
- Status Icons - Font Awesome free (SIL OFL 1.1 License)