I'd think a using a definition from the site you're on would be reasonable. I'm occasionally a cager, though I spend more time on my bike.
Back to the original question. Adrenaline? Not usually, I've been riding with other traffic long enough I'm mostly inured to it. There are a few exceptions, when I've hopped on the only road around only to find high volume, high speed traffic, and nowhere to run. That'll get my heart pumping!