@NicDup and one thing that hasn’t been mentioned here is that the algorithm is very sensitive about the HR and GPS data quality. Any glitch will result in the measurement not to be updated.
While running you need to have HR up in certain zones for some 15 minutes or more. I am not providing any specifics because what I heard from Suunto Support is not in line with the field testers’ instructions here in this forum.
I have had Vertical for a year now and I never seen VO2max yet. But it’s just probably me being too fat and unable to run 15 minutes in Z4-Z5… 😞 And up here in north we have worse GPS coverage and we are experiencing radio signal interference from Mordor.