I guess in the end I"m not sure that you ever easily control the rush, but you can mostly control what you do when the rush hits you.. as to an automated response basically as I can't think of the exact correct scientific term right now.
Exactly, and I think we're talking about two different things here. The OP was talking about suppressing the adrenaline release that happens automatically when you get into a "fight or flight situation." I think that's very difficult; it's a physiological response that happens whether we want it to or not..
You're talking about practicing something enough so that muscle memory takes over and it's automatic--you don't have to think so the adrenaline rush (which clouds your thinking) doesn't affect the task at hand. Like drawing a pistol, clicking off the safety, aiming, and shooting in one smooth motion without having to think about it.
