Applicability of a Change of Direction Ability Field Test in Soccer Assistant Referees

The aim of this study was to examine the applicability of a test for change of direction ability (10-8-8-10 test, involving line and sideward sprinting, 36m) in elite level Soccer Assistant Referees (AR). One hundred AR of the first-second and third Italian Championships (ARA-B and ARC, n=50, respectively) performed the 10-8-8-10 on three separate occasions. Twenty AR authorities scored test relevance (1 to 5 scale, from trivial to very large) for logical validity using a questionnaire. Construct validity was examined comparing ARA-B and ARC for 10-8-8-10 performance. Short-term reliability was assessed testing a random se lection of ARs (n=64) over three separate occasions every other day. Performance in the 10-8-8-10 test was assumed as total coverage time using telemetric photo-cells. Results showed that the 10-8-8-10 test was perceived as possessing from large (n=4/20) to very-large (n=16/20) relevance to AR physical match-performance. No significant performance difference was found between competitive levels p=0.57). Area under the curve (AUC=0.49; p=0.87) showed no significant sensitivity of 10-8-8-10 in detecting competitive-level difference. The ICC (n=64) and TEM (test 2 vs 3) values were 0.90 (p<0.0001) and 0.18 s, respectively. This study showed that the 10-8-8-10 test posses logical validity, good reliability and it is independent to co mpetitive level. As such, this original investigation represents the first step in the identification and assessment of a valid and reliable AR COD test. Given the strength of our findings, governing bodies should look to integrate the 10-8-8-10 test into the fitness test protocols devised for AR's, with scores equal or higher than 9.67 being considered as a starting point for the empirical validation of minimum selection criteria for elite-level AR's.