A donut eating challenge.
The gladiators pair up, and then choose a dozen donuts each from someplace like Dunkin Donuts, Krispy Kreme, or Honeydew. You aren't choosing the dozen that you will eat, though, but are choosing the dozen for your opponent to scarf. The temptation to choose twelve really heinous confections (say, six jelly and six maple-dipped) is tempered by the fear that your opponent will do something similar. We are talking about a Prisoner's Dilemma type situation here.
After the Machiavellian exercise that constitutes the choosing, the rest is simplicity itself. All participants seat themselves around a table, and consume as rapidly as possible their twelve donuts. The winner is whomever finishes first.
I have been told that this is a traditional contest held by the Dartmouth men's crew on their ride back to school from Eastern Sprints, and that the record is in the neighborhood of three and a half minutes.