vtrifonov-esfiddle / testhrv

Heart rate variability app for Garmin smartwatches

Test HRV

A Garmin app that measures HRV(Heart Rate Variability) in a 3 minute test. Saves the output as a Connect IQ activity.

Download

Link to the Garmin Connect IQ app store.

Measurements

• 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

Viewing Results in Garmin Connect

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:

Requirements

• 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

Dependencies

• Status Icons - Font Awesome free (SIL OFL 1.1 License)

testhrv's Issues

HR straps

Why aren't HR straps supported? They are usually more precise than the wrist watch, and precision matters for a sensitive calculation like HRV

howto

work great as a standalone app,
but howto include your algorithm in another app ?
thanks

No way to calculate HRV Score?

The app works great. It seems to do comparably well to other methods, but it doesn't develop a score based on your reading of the day or pull the data into tracking over time.

How would one use the HRV data produced by the app? I guess simple instructions to calculate the score would be fine, but it would be so much better if you were able to integrate tracking over time into the App's Garmin info.

feature request: show current HR bpm during test countdown like native garmin app

This is a great app and I hope you continue to maintain it.

Also thank you for sharing the source to learn.

This is my "easy" feature request:

• show current HR bpm during test countdown like native garmin app

Thank you for considering.

feature idea: it is possible to calculate Respiratory Rate from HRV and add into FIT

Now this is a much harder feature idea but I don't think too hard, maybe a weekend of coding and would be a really neat feature to add to HRV test?

Older Garmins but still very popular like the Fenix5/935 series do not calculate respiratory rate on their HRV stress test. Only the slightly newer Garmin models and what's frustrating even their $100 models have it but not the $500 Fenix5

But it is possible to calculate from HRV data. I've done it but I'd never figure out how to add it to your app. Oura tells us exactly how to do it:

https://d1a0efioav7lro.cloudfront.net/wp-content/uploads/2020/05/12195157/How-Oura-calculates-respiratory-rate.jpg

I've posted some code/results on the Garmin forums which may help?

https://forums.garmin.com/developer/fit-sdk/f/discussion/245469/tool-idea-calculate-inject-respiration-rate-into-fit-when-using-hrv-on-older-watches

RMSSD in title

It would be nice to have the most important metrics like RMSSD in the title for easier access and making it useful on other platforms like TrainingPeaks.