^ just out of curiosity.
My dog sleeps for approximately 19 hours a day- he is a 2-year-old GSD. Admittedly, he is on the lazy side and has been known to play dead on the front lawn when being taken out for a walk.
He gets one 1hr walk (plays fetch along the way) and a 20 min walk in addition to playing several games throughout the day (football, fetch, finding the hidden ball etc).