Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players.Castagna Carlo; Francini, Lorenzo; Krustrup, Peter; Fenarnandes-da-Silva, Juliano; Póvoas, Susana C. A.; Bernardini, Andrea; D’Ottavio, StefanoJournal of Strength & Conditioning Research: Post Acceptance: July 28, 2017 doi: 10.1519/JSC.0000000000002031 Original Research: PDF Only Abstract The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30-m interspersed with 30-s of active recovery in non-elite outfield young male soccer players. Twenty-six (age 14.9+/-1.2 years, height 1.72+/-0.12 cm, body mass 62.2+/-5.1 kg) players were tested 48 hours and 7 days apart for 5x30-m performance over 5 trials (T1-T5). Short- (T1-T2) and long-term reliability (T1-T3-T4-T5) were assessed with Intraclass Correlation Coefficient (ICC) and with typical error for measurement (TEM). Short- and long-term reliability ICCs and TEMs for total sprint time and best sprint performance were nearly perfect and satisfactory, respectively. Usefulness (as smallest worthwhile change and TEM ratio) resulted acceptable (i.e =1) and good (i.e >1) for total sprint time and best sprint performance, respectively. The present study revealed that the 5x30-m sprint test is a reliable field test in the short and long-term when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials. Copyright (C) 2017 by the National Strength & Conditioning Association.