Running pain I usually just fall down to the ground and just lie there for a moment.
But, I had a 20 mile run that was reaaaallly painful, so I sorta yelled from it for a minute.
When I have a small annoyance I just say freak, and mumble underneath my breath.
When it is pain I bring on myself, then I usually enjoy it (but I rarely do that, and it is usually started unintentionally, crap, thinking about it makes it irresistible).
If I have sore muscles, I say ow a lot.
Oh, if I have a muscle that starts hurting when I am running, and I need to finish, I just repeats: ow, ow, ow, ow, ow, ow,
Finally, with stomach aches, I rumble sorta. If that makes any sense?