I know this is not scientific at all, but Thor is 2 1/2 years old and 3 lbs. He is exceptionally vigorous for a yorkie. I try to make sure he gets 90 minutes of exercise a day, and that's just enough to keep him relaxed and relatively non-barky the rest of the day. I think he'd be happy to have another daily hour of hard play.
In other words, he seems very healthy to me. |