HRV4Training can now be used to read HRV data from the Health app, convert that data (SDNN) to Recovery Points (a more readable metric), and analyze your physiology similarly to what we normally do when you measure using the phone camera or an external Bluetooth sensor. You can learn more about this feature in this blog post, while below we go more practical on how to use your Watch with our app.
Due to some limitations in the way apps can communicate with the Apple Watch, you need to follow the following steps in order to gather meaningful data:
If you do not get your data in Health right after using the Breathe app, try to synch your Apple Watch and it will show up a few seconds afterwards.
Always remember that context is key, so while the Apple Watch writes somewhat random HRV numbers also during the day or night, that data could be affected by artifacts, and it is always decontextualized.
To properly interpret physiology, data must be acquired under standard, reproducible conditions, and the best way to do so is with a measurement as soon as you wake up, or with a night long measurement (not just a minute or two over a night).
What are Recovery Points? A more human friendly HRV score. For more information, read this.
How can you use SDNN instead of rMSSD to generate Recovery Points? SDNN captures physiological stress similarly to rMSSD hence it can be used in a similar manner. For more information, read this.
How accurate is the Apple Watch in measuring HRV? Very accurate, provided you stay completely still and use the Breathe app to take a measurement. For more information, read this.
When should I use the Breathe app to take a measurement? First thing in the morning.
How much time do I have after measuring with the Breathe app, to fill in my tags in HRV4Training? You have one hour. When you tap 'read from Health' we always check only the last hour, and see if we can find any HRV scores in the Health app, then take the last one. For this reason, we highly recommend reading data right after you have measured.
Why can I see only Recovery Points and Heart rate instead of all HRV features when using the Apple Watch to measure? The Apple Watch does not provide us with RR intervals that could be used to compute different features, but only with SDNN. Hence, other features cannot be computed, apart from the Recovery Points that we show in the app.
Should I use the Watch or the camera? While the watch provides accurate data under ideal conditions, the metrics reported are limited with respect to the ones we can compute directly using the camera or a bluetooth sensor. Similarly, having no access to RR intervals or raw data, we need to trust Apple to correctly identify and remove potential artifacts. Hence the camera still remains our preferable method, unless you find it uncomfortable or are experiencing any issues.
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1. Intro to HRV
2. HRV 101
3. How to use HRV, the basics
4. HRV guided training
5. The big picture
6. HRV and training load
7. HRV, strength & power
1. Context & Time of the Day
3. Paced breathing
4. Orthostatic Test
5. Slides HRV overview
6. rMSSD vs SDNN
7. Normal values and historical data
1a. Acute Changes in HRV
1b. Acute Changes in HRV (population level)
1c. Acute Changes in HRV & measurement consistency
1d. Acute Changes in HRV in endurance and power sports
2a. Interpreting HRV Trends
2b. HRV Baseline Trends & CV
3. Tags & Correlations
4. Ectopic beats & motion artifacts
5. HRV4Training Insights
6. HRV4Training & Sports Science
7. HRV & fitness / training load
8. HRV & performance
9. VO2max models
10. Repeated HRV measurements
11. VO2max and performance
12. HR, HRV and performance
13. Training intensity & performance
14. Publication: VO2max & running performance
15. Estimating running performance
Camera & Sensors
1. ECG vs Polar & Mio Alpha
2a. Camera vs Polar
2b. Camera vs Polar iOS10
2c. iPhone 7+ vs Polar
2d. Comparison of PPG sensors
3. Camera measurement guidelines
4. Validation paper
5. Android camera vs Chest strap
6. Zoom HRV vs Polar
7. Apple Watch and HRV
8. Scosche Rhythm24
9. Apple Watch
1. Features and Recovery Points
2. Daily advice
3. HRV4Training insights
4. Sleep tracking
5. Training load analysis
6a. Integration with Strava
6b. Integration with TrainingPeaks
6c. Integration with SportTracks
6d. Integration with Genetrainer
6e. Integration with Apple Health
6f. Integration with Todays Plan
7. HRV4T Coach advanced view
8. Acute HRV changes by sport
9. Remote tags in HRV4T Coach
10. VO2max Estimation
11. Acute stressors analysis
12. Training Polarization
13. Custom desirable range / SWC
14. Lactate Threshold Estimation
15. Functional Threshold Power(FTP) Estimation for cyclists
16. Aerobic Endurance analysis
1. HRV normal values
2. HRV by sport
3. HRV normalization by HR