Reliability and Validity of a New Test of Agility in Male Soccer Players

Agility testing is an important aspect of soccer and to the author's knowledge, no soccer-specific agility assessment tool has been created. Agility is the process of coordinating appropriate parts of the body in a rapid and functional manner in the face of environmental constraints. Based on this definition and the physical requirements of soccer, a new soccer agility test (NSAT) was developed. The purpose of this study was to evaluate the reliability and validity of the new agility testing protocol designed to measure agility in competitive male soccer players. In addition to reliability, concurrent and discriminant validity were the focus of this study. A total of 55 male soccer players, from three different levels of competition PDL (22.1 +/- 2.7 years; 178.1 +/- 6.2 cm; 76.3 +/- 7.0 kg), Reserve (15.4 +/- 1.5 years; 172.2 +/- 7.2 cm; 65.0 +/- 10.1 kg), and Elite (10.9 +/- 0.8 years; 138.4 +/- 21.5 cm; 39.7 +/- 7.7 kg), were recruited. All participants performed the T-test and the NSAT in random order on two separate occasions in order to assess agility performance. The NSAT was found to be highly reliable within-day (ICC: PDL = .88-.90; Reserve = .91-.92; Elite = .88-.89) based on analysis of the fastest trials performed by each participant for all teams. However, between-day reliability was found to be low for the PDL (.52) and Elite (.22) teams which may warrant the introduction of a formal familiarization session in order to account for possible learning effects. Concurrent validity was only confirmed for the Reserve ( rDay1 = .75; rDay2 = .55) and Elite (rDay1 = .68; r Day2 = .60) teams with moderate to high correlations being found between the T-test and the NSAT. These results may suggest that the NSAT and T-test measure different constructs when testing high level soccer players, based on the results found when evaluating concurrent validity for the PDL ( rDay1 = .21; rDay2 = .48) team. The NSAT was also shown to discriminate among the three different teams on testing Day 2 [F3x2x2(2,39) = 6.08, p > .05] with regards to time to completion.