Fitness assessment in talented football referees: an academy based longitudinal field-study

Background: This study aim was to profile physical fitness in talented football referees (FR) with performance relevant field-tests across time. Methods: Thirty-eight male FR (age 28±1.5 years, height 178±5.1 cm, body mass 69.0±7.34 kg, body fat 17.2±2.87%) were observed for 15 months. Endurance was assessed with the yo-yo intermittent recovery test level 1 (YYIR1) and repeated sprint ability (RSA) with 5×30 m line-sprints with 30 s recovery (5×30 m). Long sprint endurance (LSA) and change of direction ability (COD) evaluated with novel field-tests. FR was tested six times (every three months) during the study. Results: YYIR1 performance showed large increments across testing occasions. Sprint time in the COD largely and significantly decreased across the testing occasions. Very large associations were reported between 5×30 m and LSA tests grand mean (r=0.89, 0.78-0.94, P<0.0001). A nearly perfect (r=0.97, 0.94-0.99, P<0.0001) association was observed between 5×30 m best sprint and 5×30 m grand means. Conclusions: The results of this study revealed ability-related variations in performance across time. The effect of training and competitions on the determinism of physical fitness in refereeing seem plausible. Interestingly, sprint endurance tests shared a very large variance proposing tests interchangeability and mutual physiological demands. This study information provides useful information for the development of sound field-tests batteries in talented FR.