The challenge for the second week of K9 Kamp was to play ball. I can't say Sully really enjoys ball very much, but he'll chase it for a few minutes if you encourage him enough.
When we first got Sully, he didn't know how to play at all. We had to teach him how to play with toys. And we taught him how to retrieve. So it's not a very natural activity for him, it's more like a more relaxed obedience session than a real game. But at least he's still running around getting exercise from it! And he does enjoy it, just not as much as some dogs who seem to never want to stop playing ball. He wants to stop after about a dozen throws. :)