Imagine repeatedly running the 120-metre length of a rugby league field from dead-ball line to dead-ball line for 80 minutes, while making tackles and being tackled, or passing or kicking the ball and continually shouting directions to teammates.

That is what NSW halfback Mitchell Pearce did in State of Origin I, and tracking devices worn by the Blues and Maroons showed he again played with the highest intensity of any player in Origin II, while also running the furthest (8.2 kilometres) and fastest (33.7km/h).

Pearce, who will head into Wednesday night's decider at Suncorp Stadium with the chance to win his first Origin series in a Blues jersey, can lay claim to being arguably the fittest player on the field after averaging an intensity of 120.4 metres per minute in Origin I and 112 metres per minute in Origin II.

The Catapult data, which has been made public for the first time through the Telstra Tracker, impressed even those who work closely with Pearce at Sydney Roosters and to highlight the athleticism and endurance of the game's stars, Coogee Dolphins and Moore Park Broncos players wore the devices last weekend.