Over on GolfForGeeks, the following assertion was made:

I nominate PaintBall. It can be as strenuous or as sedate as you like, you can avoid direct sunlight if you so wish, and ''it maps well to extreme practices'' -- PeteHardie

Now I'm assuming that by "extreme", Pete meant XP, but it's an interesting question nevertheless.  Any further insights on this?  Apart from the fact that eXtreme Paintball and eXtreme Programming share the XP?

''I am not certain if I made the "maps well" comment or not.  However, as I think about it, it does - you get immediate feedback, it is strongly supportive of mentoring, pairing is a good way to share talents, etc'' --PeteHardie

Maps to PairProgramming?  Ha!  You've got to be kidding.  -- TheSniper
''Ever get caught in a crossfire? How many people were firing at you?'' --PeteHardie

It probably shares some of the eXtreme Programming values: Communication, Simplicity, Feedback and Courage.

''However, it injects the unknown of accuracy. Ever fire one of those paintball markers? You can't hit a 55 gallon drum at twenty paces, much less a running man!''