VO2 max seems like another con! Apparently you can only have a VO2 max if you run according to most watches. I once had a Garmin watch that would very rarely calculate it from a bike ride - even though all of them included heart rate and power meter readings. My current watch is very French when it comes to VO2 max and just shrugs its shoulders if a run isn't recorded - which it never has been and probably never will as that is one way to kill off my fucked up back and knees! Row for 30 or 40 minutes and meh, VO2 max is not a thing for you! Cycle for 3 hours tracking heart rate and power settings, fuck you, no VO2 max for you fella!