Validity of a Modified Special Judo Fitness Test: A Novel Approach Using Dummies to Improve the Test’s Ergometric Properties

Objective: To examine the criterion validity of a modified Special Judo Fitness Test (SJFT) using dummies compared with the original version. Methods and Materials: Forty-seven judo players (22 women and 25 men) participated. The criterion validity between the original and the modified SJFT was examined using the intraclass correlation coefficient (ICC). Linear mixed models employed the two SJFTs as within-subject repeated fixed effects and subject identification as a random effect. Student´s t tests for independent samples were used to compare the two SJFTs’ parameters between the novice and advanced groups; Hedges’ g was used to interpret effect sizes. Findings: A strong consistency was observed between the two versions (ICC [95% CI] = 0.913 [0.843–0.951], p < 0.001). Both tests demonstrated specificity, differentiating novice from advanced judokas and men from women. However, systematic mean differences were observed between the original and modified tests, and agreement across parameters was lacking. Conclusion: Preliminary evidence indicates that the modified SJFT may be a useful alternative for assessing judo-specific performance, but it should not be considered interchangeable with the original test. Further studies, particularly those examining test–retest reliability and ecological validity, are needed before recommending its widespread application.