It is documented that a factory reset removes all user data from the watch, including the fitness data.
Does anyone know if the fitness data (e.g. VO2max, lactate threashold, training load) will be uploaded to the watch once I connect it to the Garmin Connect App? I have seen this advice from Garmin regardind backup
https://support.garmin.com/en-US/?faq=AXV7LuWgc73v21nq6nbDa6
but surprisingly it doesn't specifically mention the fitness stats.