The aim of this study was to verify whether referees' maximal aerobic power could influence competitive match exercise intensity. Eight elite-level referees (mean +/- SD age, 37.6 +/- 3.4 years) were each observed during 2 Serie A matches (n = 16), and the mean of each match activity was used for analysis. Match activities were monitored with encoder-equipped cameras. .V(O)(2)max was assessed under field conditions with a portable device during a progressive multistage protocol. The .V(O)(2)max of each subject was expressed in absolute terms (.V(O)(2)max(ab), L.min(-1)), relative terms (.V(O)(2)max (rel), ml.kg(-1).min(-1)), and independent from body mass (.V(O)(2)max (ind), ml.kg(-0.75).min(-1)). Significance was set at p < or = 0.05 for all measurements. Total distance covered during the match correlated significantly with .V(O)(2)max (ind) (r = 0.77) and .V(O)(2)max (ab) (r = 0.87). .V(O)(2)max (ind), .V(O)(2)max (rel), and .V(O)(2)max (ab) correlated negatively (p < 0.05) with the time spent standing still during the match (r = -0.90, -0.85, and -0.86, respectively, p < 0.05). During the first half of the match, referees with higher levels of .V(O)(2)max (rel) (r = 0.93, p < 0.05) and .V(O)(2)max (ind) (r = 0.90, p < 0.05) were able to cover more distance at medium intensity. In the second half of the match, medium-intensity distance and low-intensity time correlated significantly (p < 0.05) with .V(O)(2)max (ab) (r = 0.76) and .V(O)(2)max (rel) (r = 0.75), respectively. The results demonstrate the positive influence of .V(O)(2)max in determining both the total amount of distance covered and the exercise intensity during a game. Higher levels of .V(O)(2)max may provide referees the opportunity to be more active and therefore closer to the action on the field during the game.