RESUMEN
Abstract Aim: This study aimed to verify the reproducibility of an endurance test for master swimmers. Methods: Seventeen male swimmers, aged from 30 to 50 years (35.06 ± 5.36), weight (78.71 ± 13.06 kg), height (174.35 ± 0.07 cm), participated in this study. The participants underwent the Progressive Swim Test (PSwT), which corresponds to swimming progressively to exhaustion in a 25-meter pool, guided by the recording of sound signals indicating the swimming rhythm. We verified the following variables: heart rate before the test (BHR) and right after the end of the test (AHR), followed by the rate of perceived exertion (RPE) and a total of laps performed (SN - swimming number). For comparison between the three days of tests, the one-way repeated measures ANOVA with Tukey's Post-Hoc was performed. Relative reproducibility was performed by the r test and the intraclass correlation coefficient (ICC). Absolute reproducibility was determined using the coefficient of variation (CV) and the confidence interval (CI). Results: The results showed high reproducibility in (PSwT) in master swimmers in the analyzed variables of intergroup and intragroup with relative reproducibility of r > 0.60 and ICC > 0.70 and absolute reproducibility with CI 95% (lower −1.10 and upper 0.99) and CV < 10%. Most of the cases were within the limits of agreement of the Bland-Altman tests, all variables were considered a level of significance with (p <0.05). Conclusion: The Progressive Swim Test (PSwT) is a reproducible instrument in the assessment of endurance in master swimmers.