I'm 63 and have always been active and usually going to the gym, although not consistently lately and Vivosmart 4 measures my VO2 max as 31 and says this is poor for my age. However, I found charts (https://www.runnersblueprint.com/vo2-max/) online that put me right in the middle, average for my age. I'm really trying to give feedback to Garmin here but didn't find a way to do that.