Validity And Reliability Of A Repeated Defensive Movements Test For Beach Volleyball Players

Abstract

PURPOSE: To design and report reliability and validity of a new test for assessing defensive repeated defensive movements on the sand (Double-X). METHODS: Fourteen beach volleyball male amateur players (24±3 yrs; 1.91±0.11 m height; 79.66±10.41 kg weight) were voluntarily recruited for this study. The Double-X test consisted in repeating diagonal runs in different directions between 4 cones situated at the corners of the sand court (separated 8 m). The whole test was video recorded with a Casio ZR-1000 high speed camera (240fps) and the frames were counted to determine the time of different intervals. The second tests consisted in performing block jumps and attack jumps on the sand. Coefficient of variation (CV) was calculated and Person product-moment correlation was used to compare Double-X and jump ability. We also used compared the results of the tests and lactate samples at the end of the test. RESULTS: CV was less than 3% in all tests. Significant correlations were found between Double-X time and Block jump (r=-0.78; p0.05). Mean lactate levels of 7.6±2.1 mMol/l were found. We also found relationships between different tranches of the test that indicate differences in the ability to perform quick repeated defensive actions on the sand. CONCLUSIONS: Double-X constitutes a reliable and valid test for repeated defensive movements on the sand court. Lactate levels of the subjects indicated that this is a specific anaerobic test.