So i have about three year old whippet breed dog at home. we adopted
him when he was about two to three moths old and he loves us now.
He used to play a lot but now he got kinda boring. the thing is someone told me a dog at the age of 3 supposed to be active!
But all he does is sleep on the bed (couch) and all he's interested in is food and going for a walk. He goes walking once a day in the morning for about 2 hours. then when i come from school about 3pm he doesn't want to play but is i throw the ball he'll just run after it run back home and goes to sleep with it.

what can i do to make him more playful and active.
No stupid answers please thanks!