Alright, heres another attempt since the commanding shout thing was already posted.
To do this trick you need to get a talent in the Arms tree called "Anger Manegement". This talent allows you to build rage as long as your in combat.
Now, once you join the arena, immediatly use Bloodrage to put yourself into combat, and then spam battle or commanding shout for the full minute you get for preperation. The game mechanics keep you in combat, because every time you buff someone in combat with your battleshout (yourself in this case), it keeps you in combat. Since you have the arena preperation buff on, your shouts cost no rage, so you will keep gaining rage.
You can use this trick to get up to 50+ rage before the arena gates even open.
To do this trick you need to get a talent in the Arms tree called "Anger Manegement". This talent allows you to build rage as long as your in combat.
Now, once you join the arena, immediatly use Bloodrage to put yourself into combat, and then spam battle or commanding shout for the full minute you get for preperation. The game mechanics keep you in combat, because every time you buff someone in combat with your battleshout (yourself in this case), it keeps you in combat. Since you have the arena preperation buff on, your shouts cost no rage, so you will keep gaining rage.
You can use this trick to get up to 50+ rage before the arena gates even open.