Journal of sports sciences vol:25 issue:7 pages:805-813
The aims of the present study were ( 1) to analyse the physical demands of top-class referees and ( 2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under- 17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise ( P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance ( P < 0.01), spent more time standing still ( P < 0.05), and covered less ground cruising ( P < 0.05), sprinting ( P < 0.05), and moving backwards ( P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased ( P < 0.05) in the left attacking zone of the filed. There was also a decrease ( P < 0.05) in performance in the period following the most highintensity activity, compared with the mean for the 90 min. Time spent performing high- intensity activities during a match was not related to performance in the 12- min run ( r(2) = 0.30; P < 0.05), the 200-m sprint (r(2) = 0.05; P < 0.05), or the 50-m sprint ( r(2) = 0.001; P < 0.05). The results of this study show that: ( 1) top- class referees experienced fatigue at different stages of the match, and ( 2) the typical field tests used by FIFA ( two 50- m and 200- m sprints, followed by a 12- min run) are not correlated with match activities.