I've been confused for a long time on the exact formula that Garmin uses. I am new to cycling and started off with a very poor Vo2 max. Since then I've lost weight and have become stronger at cycling but I'm focusing a lot more on longer endurance rides rather than all out short duration sprints - and therefore I don't see my Vo2 max changing much. That's why I'm curious as to what is the exact formula and if I need to do anything in particular to improve my Vo2 max.
I use the Garmin HRM Pro Plus for measuring HR, paired with a FR 965 and an Assioma Duo power meter.