Where to start...?
Ok firstly I'm a woman, so not as strong as a lot of guys out there.
from experience I'd say I do pretty well against people of all sizes. I've fought a 7 foot tall karate trained man before and still won (though that was sports karate).
I have trained in various forms of karate, aikido, and wu shu all my life (on and off) but currently I do karate with my boyfriend, and the club I'm at is really old-school... we spar without mitts or mats or anything except mouthguards; and I'm always being put against the many blackbelts at my club (I'm not a blackbelt in shotokan). They do not hold back.
At the same club I came third at the UK national tournament in 2009. I could have gone back but I couldn't be bothered (it's my first tournament and it's pretty boring lol).
So I'm fairly well experienced against the 'adrenaline dump' the OP describes.
I've had a few real life fights aswell, the first, when I was very young I was out witha friend in my village, and 2 bullies from the school started giving us trouble. they were both boys so we decided to run (always the most sensible option!) but one of them jumped on my back (the fat one too :/).
Somehow, and to this day i still don't know how... I threw him right over my shoulder so he went arse-over-tit and landed sprawled on his back looking up at me. He was so shocked we just jumped over him on the street and carried on running lol. I don't know what the other guy had been doing all this time (obviously I had my back to them) but I never did get any trouble from them again... They wouldnt even look at me.
More seriously, when I was about 17/18 I had a guy pull a knife on me outside a youth centre, I managed to floor him in one hit but I really held back... I felt very calm and measured throughout the whole thing, it's weird how much detail you take in with situations like that.
Anyway as soon as he was down I legged it once again lol. (discretion is the better part of staying alive!) Soon as I was clear I rang the police and he later got arrested... so all's well that ends well.
What I still remember is when I was running away, I was deliberately running at a reduced pace so I wouldn't tire myself out in case I needed to fight him off again; I was also watching the shadows on the floor from the streetlights... You know how someones shadow is really long at night? well I figured i'd see his shadow behind me to give me good warning.
Also when I made the call to the fuzz It was from down a long open street with only 1 way in and an escape route planned in my mind lol, so I could see him from a long distance.
Oh and the 'fight' took place in front of a bunch of people from the youthclub, so I got a bit of a rep afterwards lol (some of them jumped on him after id floored him so I'm very thankful to them for that).
Moral of the story? avoid fights all you can