The Development of the Special Brazilian Jiu-Jitsu Fitness Test: Takedown Zone (SBJJFT-TZ), Gi Formula

Abstract

Background: There is a consensus among combat sports researchers regarding the important role of evaluating the comprehensive special fitness and performance of athletes. This is due to the specific structure of tasks performed in these sports as they require a comprehensive and integrated function of broadly understood physical fitness. The present study aimed to develop and check the Special Brazilian Jiu-Jitsu Fitness Test: Takedown Zone (SBJJFT-TZ), Gi formula’s reliability. The major task of this sport-specific tool is to illustrate the comprehensive special fitness and performance of professional Brazilian jiu-jitsu athletes. Methods: The study covered 27 BJJ athletes (age in years: 25.36 ± 2.99; height: 175.04 ± 5.70 cm; weight: 76.56 ± 8.59 kg; BMI: 24.96 ± 2.30; 6.33 ± 2.51 years of training) with a high sports skill level. A coaches’ ranking of the athletes studied according to sports achievement was developed. An experimental approach to the problem was employed, with the SBJJFT-TZ assessment, including throws and specialized locomotion, performed on two dates (seven days apart). The test parameters were recorded and, using a specialized formula, an index showing comprehensive special fitness was calculated. To verify the test’s validity and reliability, using statistical procedures, the results were comparatively analyzed (Student’s t-test for the dependent variables), and the relationships between rankings were examined (Pearson’s r linear correlation). The level of statistical significance was set at p < 0.05. Results: The analyses showed statistically significant relationships with very high strength between coach ranking and SBJJFT-TZ parameters for both dates (R = 0.73–0.88; p < 0.001). A similar trend of significant correlations was noted between the first and second SBJJFT-TZ dates (R = 0.96–0.98; p < 0.001), and the strength of the coexistence was almost complete. The test-retest procedure for SBJJFT-TZ showed similar levels for the parameters studied, without significant variation (p > 0.05) but with a weak effect profile (d = 0.03–0.06). Internal variation in the variables was very low (HR CV < 10%) and moderate (Throws and Index CV = 20.82–32.25%). Significantly different throwing performance between sets was shown, with an advantage in the first round of work compared to the second, and a moderate effect (p < 0.05; d = 0.38–0.39). Conclusions: The identification of relationships, the comparison, and the test-retest procedure showed the high application value of SBJJFT-TZ. The proposed tool provides a reliable cross-sectional evaluation of BJJ athletes’ special fitness and performance in the stand-up fighting plane, as well as at the moment of achieving an advantage over the opponent, and favors implementation in field conditions.