This sounds just like my baby Scottie at 8 months! I would walk him for 2 hours and he'd still have energy to wanna play all night at home. It sounds pretty typical Yorkie to me.
I just wanted to note that I've read that it's not a good idea to run with your puppy under 1 years old. Their bones are still developing and the running impact on their bones/joints may be damaging. It's best, if possible, to wait until they're over a year (or 1.5 years? can't remember exactly) before you go running with them over long a duration. Personally, I wanted to be better safe than sorry so I never ran with Scottie. After all, their toothpick-thin legs are so delicate. And besides, I am not a runner anyway. :P
Oh and also, besides physical activities, you can also tire him our with mental exercises. You'd be surprised at how tiring training sessions can be for them!
