Enable the HRV recording at Menu > System > Data recording > Log HRV.
Enable the HRV recording at Settings > Physiological Metrics > Log HRV.
Turn on your device and enter the Menu. Now press UP and DOWN for 10 times. You will enter the so-called diagnostic menu. Select and change HRV to enable HRV data recording.
We assume no responsibility for possible problems! You do this on your own risk. (Anyway, we enabled HRV on our devices as well and did not experience any issues so far.)
Have a look at the5krunner.com. You’ll have to download a *.fit file and save it on your device.
Please let us know if you have wishes or have encountered bugs. We give our best to make Runalyze as good as possible for you. - Therefore we would be interested in your suggestions for improvement. In general most questions, problems and ideas are more appropriate to ask in the forum.