Confiabilidad test-retest intraevaluador e intradía para pruebas de rendimiento físico en jóvenes tenistas chilenos

In tennis, the use of standardized tests seeks to provide a useful complement tool for performance monitoring, becoming a very valuable instrument for evaluating the athlete's physical condition. The aim of the study was to assess the intra-rater and intra-day test and retest reliability for physical performance in young Chilean tennis players. The sample size was of 86 young tennis players (15.4 ± 0.8 years old), male = 58; female = 28. Variables of physical performance were tested, 20 m. sprint test; modified agility test (MAT test); sit-and-reach test and shoulder flexibility; hand grip strength (HGS); horizontal jump (HJ), medicine ball throw (MBT), countermovement Jump (CMJ) and Abalakov (ABK). To examine the intra-rater and intra-day test-retest reliability, subjects performed the tests twice on the same day. Results showed excellent test-retest values of relative reliability (intraclass correlation coefficients; ICC between.80-1.00), respect to the absolute reliability, all the tests presented small values of standard error of measurements (SEM) and adequate values for the minimal detectable change (MDC). Physical performance tests used in this study reported high intra-rater and intraday test-retest reliability for all male and female individuals, except for agility in men, which shows moderate relative reliability.