How much exercise is TOO much for a 1 year old lab? Hannah is outside for about three hours a day and I would say for atleast an hour we play fetch. She never seems to tire but I am afraid maybe I am over exercising her, is that possible? Even after we have been playing for an hour she is still bringing me the ball even though she's panting and slobbering all over the place. Although the good thing is after that hour she comes inside and is napping for a good hour or hour and a half. Should I not let her play fetch for an hour at a time?