I tried a few times when I do heavy bag work to listen to som fighting or combat songs with earplugs. I am normally a very calm person, and after a day in the office, I surely don't need to get more calm. To get into "fighting mode" before the session, rather then midway though listening to some fighting music or something similar helps get into the mood faster. It seems to help me get better "chinkuchi" and respond faster on the heavy bad, rather than jsut stepping into the dojo after a day at the office thinking about many things that have nothing todo with fighting
I like "mental warmup" along with "physical warmup".
It happens that i just about make it to the dojo, without having at least 30 mins to torture the heavy bag before the class, those days are my worst, as i step right into the class mentally unprepared.
Some adrenaline is required not only for delivering punhces, but also for taking them! I sometimes even do a brief kiai or breat hout when I plan to take a punch. It helps to tense up your body maximally, and here you need to some adrenaline - or so i feel, otherwise I feel to soft or weak.