From the wiki:
Although a game designer, Miyamoto spends little time playing video games, preferring to play the guitar, mandolin and banjo. He has a Shetland Sheepdog named Pikku that provided the inspiration for Nintendogs. He is also a semi-professional dog breeder. He has been quoted as stating, “Video games are bad for you? That’s what they said about rock and roll.” Miyamoto also has stated that he has a hobby of guessing the measurements of objects, then checking to see if he was correct, and apparently carries a tape measure with him everywhere.