标题：Body composition, isometric hand grip and explosive strength leg – similarities and differences between novices and experts in an international competition of Brazilian jiu jitsu
摘要：Background and Study Aim: Brazilian jiu jitsu (BJJ) is gaining thousands of practitioners in all countries; however, there is a lack of scientific research related to this sport. We wanted to establish the indicators approached by BJJ athletes to sporting excellence, which is the reason why we divided the subjects into two groups: experts and novices. Additionally, the aim of this study was to knowledge about the body composition, and similarities and differences in the performance of BJJ athletes focusing on two variables: isometric hand grip and explosive strength legs. Material and Methods : Fifty six BJJ players, who were contestants in the European Open Jiu-Jitsu Championship 2013 in Lisbon (Portugal), took part in this study. Novice group (n=24; age: 29.9±5.8 yrs), Expert group (n=32; age: 30.5±4.7 yrs). Body mass was measured with Bioimpedance, and handgrip strength was measured with a dynamometer. Explosive strength leg was measured from a force platform with the Countermovement Jump (CMJ) test. Differences between experts and novices were established with the t Student’s test or Mann-Whitney U test for the parametric and non-parametric variables respectively. Results: Experts obtained significant differences over novices on isometric hand grip strength in both hands; as for the variables of CMJ, significant differences were found in Height of jump, peak power, velocity at peak power and average power. Conclusions: BJJ athletes with higher experience, training, and level (expert group) have more adaptations and improvements than the novice group. This can be seen by their higher records in isometric handgrip and the higher explosive strength in their legs
关键词：art of defense; countermovement jump; force platform; sport performance
