As I said, all information used in this interpretation is gathered from different sources but all by the people mentioned above.
I’ve been reading literally for days to bring it all together. Most of what I found and used has already been mentioned in one of these threads:
It started of March 21 and resulted first in the HRV chart on te Fitness page based on Marco Altini’s HRV4Training blog. Last summer came the iThlete interpretation.