Quite a few years ago I had an employee in one of my organizations who was world ranked in the sport. It was called "Ultimate Frisbee" He was a graduate of Yale and he gave me a demonstration of the sport and it was seriously dangerous. He had one in his office so we went into the "coffee room" which had metal walls. He threw the Frisee against the wall which dented the wall and folded the Frisbee in half. He was scheduled to go to LA for his vacation and participate in a game of "Ultimate Frisbee". They were coming from all over the world to play. They stand in a line about XXX feet from each other and throw it at the other line. It is not like standing on a beach and throwing one back and forth. These players were serious. Moral: Be careful when you sign up as it may be more than counted on.