I'm late to this thread;
lots of good answers but I want to pour one for the motorsport elite.
F1 drivers:
losing 3kg of fluid in 90 minutes, heartbeat constantly over 150bpm, fully clothed with a nomex underlayer in a cramped cockpit that reaches over 50° C; pulling up to 5G laterally and longitudinally in many corners each lap; barely seeing the road through a tiny slit in their helmet from their almost supine position; constantly fiddling with a 20+ buttons steering wheel, talking with the pit on the radio, feeling the constantly evolving car balance with their asses; all while continously hitting dead-on time windows of hundredths of second for braking, changing gears and steering.
I saw a video of a regular-guy amateur driver getting a test-ride in a f1 car, he could never reach over 30% brake pressure giving it all with his left leg in his whole session, these guys go 100% with insane timing dozen times each lap.
MotoGP and Superbike riders:
these guys cling on a 200kg beast for over 20 laps, using each and every muscle of their body to continously slide around and adjust position to balance the bike, fight vibrations, transfer weight, make it lean, bring it up; heart racing 150+bpm as well; they smear their body in the gravel multiple times each race weekend; they hop on again with stitches, broken fingers, cracked ribs, patched up ankles and shoulders.
Vibrations and brake force are so extreme nowadays that almost all the pro riders develop compartment syndrome and end up getting their right forearm cut up lenghtwise to ease the cramps pain. Oftentimes, they get arm pump surgery after a race and are back to the next race a week later with metal stitches running up their whole forearm.
Elite motorsport athtles do not train their body to the extreme maximum like many other athletes, as their results don't depend on extracting every last ounce of performance from it, they just need it to be fit just enough to not impede the expression of their handling talent; but they do take such an intense beating every race, and when you factor in the extreme mental application - reflexes, sight, focus, strategic and creative thinking... - I think they deserve to considered among the top dogs.