A avid cyclist who rodes a carbon bike, shaves is leg, wears a nice bike team kit, takes electrolytes, and hates everything else related to bike that does not match his profile. Expression popularized by cyclist/youtuber Robin Moore with his song "Performance".
Julia: I thought about you today, I saw a performance guy on Route 1.
Al: Cool! What kit was he wearing?
Julia: Not sure but he was freaking fast on a sparkling 2010 Trek Madone.