What can i give my dog to calm down?

i have a 8 months Italian greyhound and i make him run an hour and a half per day , i enrolled him on obedience classes, i tried everything!!! and he is just tooooooo toooo hipper . he breaks and chews everything!! I LOVE HIM WITH ALL MY HEART but i just cannot take it anymore, my house is a mess. WHAT CAN I GIVE HIM TO CALM HIM DOWN?