Does Apple Watch work with Elite HRV?
In order to calculate the research-backed HRV values such as RMSSD, LnRMSSD, HF, LF, etc. our software needs access to accurate R-R interval data. (More info on R-R intervals here).
At the time of this writing, the Apple Watch does not transmit accurate R-R intervals to 3rd party applications such as Elite HRV. Therefore the Apple Watch does not work with Elite HRV, and it is currently out of our control. This is still the case with the current Apple Watch 4; it does NOT share the ECG data.
The latest versions of Apple Watch now produce an "HRV" value that is primarily intended for the Apple "Breathe" app. The raw data behind these "HRV" values are not available for analysis and, to the best of our knowledge, are is not intended for calculating RMSSD, LnRMSSD, HF, LF or other trended HRV values.
The Apple Health app pulls HRV data at random times throughout the day. This offers little to no context for the HRV score, and therefore can be very misleading when trying to make a judgement from that score. The point of our Morning Readiness readings is to establish a baseline, so to take readings throughout the day without this baseline will not tell you much.
To be sure, if you are moving your hand, wrist or arm at all, then there is a very low degree of confidence in the accuracy of the HRV calculations that could be produced from the Apple Watch at this time. Even if perfectly still, there are many circumstantial variables to address such as sensor positioning, skin contact, skin thickness/color, emitter spectrum, etc. Until the raw R-R interval data or full pulse waveform data is available for analysis, we will not be able to verify one way or the other.
There are many heart rate monitors that are compatible with Elite HRV and fulfill the above requirements. For a full list, see: https://elitehrv.com/compatible-devices
There is always the possibility that Apple will expand the watch's capability and accessibility. We will update this article and our Compatible Devices page accordingly when the time comes.