57 UDC: 796.853.26.012.112 doi: 10.5937/fizkul1801057M Correspondence to: Stefan Marković, Е mail: stephan.markovic@hotmail.com EXPLOSIVE ISOMETRIC MUSCLE FORCE OF DIFFERENT MUSCLE GROUPS OF CADET JUDO ATHLETES IN FUNCTION OF GENDER Stefan Marković¹, Milivoj Dopsaj², Stevan Jovanović³, Tijana Rusovac¹, Nataša Cvetkovski¹ ¹ University of Belgrade, Faculty of Sport and Physical Education, student DAS, Belgrade, Serbia ²University of Belgrade, Faculty of Sport and Physical Education, Belgrade, Serbia ³ University of Niš, Faculty of Sport and Physical Education, Niš, Serbia Phys. Cult. (Belgr.) 2018; 72 (1): 57-70 PHYSICAL CULTURE ABSTRACT e aim of this paper is to determine the differences in general and specific explosive isometric muscle force in male and female cadet judo athletes. e results of the measured contractile characteristics were obtained by application of a standardized test battery using the isometric dynamometry method for the following five muscle groups: flexor muscles of the leſt (ŠL) and the right hand (ŠD), back (MRT) and leg extensor muscles (NOGE) and the ankle joint plantar flexor muscles (LIST). e testing included a sample of 14 participants who were competing in the system of individual nation- al championship of the Republic of Serbia for the given age category. On the basis of the obtained results, it can be argued that a general, statistically significant, difference exists between tested judo athletes in the function of gender, both for the absolute values of the variables of basic and specific explosive isometric muscle force (Wilks’ Lambda Value 0.000, F=898.61, p=0.000), as well as between the partialized (relative) values of the measured variables (Wilks’ Lambda Value 0.001, F=325.71, p=0.000). e highest level of difference between male and female athletes in relation to the absolute values of the obtained results was determined for the variables of the specific explosive isometric muscle force of the leſt hand flexor muscles (RFD max _ŠL, p=0.001), leg extensor muscles (RFD max _NOGE, p=0.003) and right hand flexor mus- cles (RFD max _ŠD, p=0.005). In relation to the relative values obtained by partialization of absolute values in relation to skeletal muscle mass (SMM) the highest level of difference was determined for variables of specific isometric explosive muscle force for the leſt and the right hand, respectively (RFD max _ŠL SMM , p=0.000; RFD max ŠD SMM , p=0.003). e summa- rized value of the gender dimorphism index (IPD) is at the level of 71.55 and 53.09% for both absolute basic (RFDF max ) and specific (RFD max ) explosive isometric muscle force, respectively. is indicates that the tested girls reached 71.55% and 53.09% of the given contractile characteristics compared to the tested boys. However, when the measured variables are partialized relative to the skeletal muscle mass (SMM), the fore mentioned differences are lowered to 101.98% and 71.58%, respectively. On general level, the obtained results have shown that there are methodological indications of scientific justification in relation to the partialization of the results of explosive isometric muscle force as a measure of development of contractile muscle potential directly responsible for the intensive manifestation of muscle force in the unit of time, in relation to skeletal muscle mass. Key words: JUDO/ CADETS/ ISOMETRIC DYNAMOMETRY/ EXPLOSIVE ISOMETRIC MUSCLE FORCE ORIGINAL SCIENTIFIC PAPER INTRODUCTION Judo is an Olympic martial sport in which the performance is determined by the optimal integra- tion of various components of the athlete’s prepa- ration that are jointly manifested in the changing conditions of the competition. It can be described as a high-intensity sport, in which athlete attempts to throw his opponent on the back or control him during groundwork combat (Franchini et al., 2007). According to the applicable Judo rules we can dis- tinguish several age categories where in the system of long-term athletes development, and in the sys- tem of the selection of perspective athletes, the ca- det and junior age categories are distinguished in their importance, while the significance of the sen- ior age category is primarily in the materialization of the maximal competitive performance through