Comment by smcl

Apple Watch is pretty poor at estimating VO2 max and it seems to be more correlated with how often you record exercises with said watch than with your actual health. For example I watched mine climb slowly as I prepared for my football season (beyond 50), then after the season started I I ended up playing and training just as frequently but without wearing the watch. After a few weeks (of me training and playing hard) during my next run it recorded me having a sharp decline in VO2 max (43-44ish iirc). When I started wearing it during training - you're not permitted during matches - it recorded me having a slow return to condition, without any changes to my routine.

That said if it's showing someone as having 30 I don't imagine they're going to be in spectacular condition