When I try to view my fitness age, I am asked to input my weight. GCM already know my weight:
More > Settings > User Settings > Weight
When I try to view my fitness age, I am asked to input my weight. GCM already know my weight:
More > Settings > User Settings > Weight
I don't know how often you need to update the weight.
Minimally each week (7 days) - see it in What Does Fitness Age Mean in Garmin Connect?