Activity profile of top-class association football referees in relation to fitness-test performance and match standard.

The aim of this study was to examine the kinematic activity profiles, cardiovascular responses and physical fitness of top-class football referees (n = 11) during the FIFA Confederations Cup 2005. Computerised match-analyses (n = 9) were performed with a two-dimensional photogrammetric video system, and the cardiovascular demand imposed on the referees (n = 12) was measured using heart rate recordings. Total distance covered was 10,218, s = 643 m of which 3531, s = 510 m was covered at high intensities (> 3.6 m · s-1). Both total distance covered (r2 = 0.59; P = 0.02) and high-intensity activities (r2 = 0.44; P = 0.05) were related to the distance covered by the ball in the same match. The referees ran at high speed 37% further (P = 0.01) in the actual tournament than during under-17 top-level officiating. After the 5-min interval during which high-speed running peaked, in the following 5 min the performance was reduced by 19% (P = 0.01) in relation to the mean of the game. Mean heart rate was 161, s = 9 b · min-1 (86, s = 3% of maximal heart rate (HRmax)). Mean heart rate (expressed as percentage of HRmax) was related in part (r2 = 0.36; P < 0.01) to the number of high-intensity activities performed in the same 5-min interval. The results of this study show that: (1) kinematic activity profiles of top-class referees can be influenced by the distance covered by the ball; (2) the amount of high-speed running (>5 m · s-1) best describes the physical performance of referees; (3) heart rate recording can be a useful tool to determine the most intense periods of a match and (4) the new fitness tests adopted by FIFA were poor predictors of match activities. [ABSTRACT FROM AUTHOR]