My wife and I have poor VO2max readings although we are very fit. Mine in particular shows I am 8 years older and poor.
The system doesn't recognise treadmill workouts which is ridiculous.
We went for a 90minute walk today and my wife's reading dropped by 3 years which seemed good. We then walked 90minutes back and her age had increased by one year! The app is a joke!
I think I'll buy a different watch as the app is so poor and inaccurate and there's no no way to contact Garmin, they aren't interested in their users.
