48 Zoran Pajic, Dusko Ilic, Vladimir Mrdakovic, Nenad Jankovic, Zeljko Rajkovic PHYSICAL CULTURE, BELGRADE, 62 (2008) 1-2 Zoran Pajic, Dusko Ilic, Vladimir Mrdakovic, Nenad Jankovic, 796.422.015.52 Zeljko Rajkovic 796.422.012.114 Original scientifc paper INFLUENCE OF TRaININg wITh INERTIONaL LOaD ON abILITy OF FORCE DEVELOPMENT aND MaxIMaL RUNNINg VELOCITy Physical Culture, Belgrade, 62 (2008), 1-2, p. 48-65, tab. 7, graph. 4, ref. 35 abstract The aim of this research was, within the scope of training with appliance of additional inertial load, to generate changes in motor performance of maximal running velocity as well as to confrm in observed variables adaptive processes for which it is supposed that they signifcantly infuence on maximal running velocity. The experiment with parallel groups was realized whereby the acting of experimental factor (inertial load) was in two levels. The frst, control group K realized the designed sprint training freely, in other words it did not apply additional load. The second, experimental group E-R ran with load fasten on their hands, and the third experimental group E-N with the load on their legs. The research contains initial and fnal measurement variables of acceleration and maximal running velocity (VTF1 i VTF2) in running at maximal sprint of 50m. Also, variables force and normalized force were observed -coeffcient force extensor in knee-joint (k-EKOL), coeffcient of heels force-(k-PFST), level of force extensor in knee-joint reached in 100 milliseconds (F 100ms - EKOL), level force of fexors reached in 100ms (F100ms-PFST), extensors in knee-joint (EKOL/r), heels fexors (PFST/r). The applied training treatment is on the level of statistical signifcance(p<0.05), infuenced on force development of applicant, because small load was applied with maximal velocity performance. It came to signifcant change in level of velocity of force development variables extensor of knee (k-EKOL) and heels fexors (F 100ms PFST) within the group with load on legs E-N and control group K. Simultaneously, in each group is signifcantly enlarged force of extensors and fexors. Velocity of running increased with E-R in the phase of acceleration. Due to connection of maximal running velocity and force variables through force infuence, it can be possible to infuence on maximal running velocity. Using experimental factor in training for force development with small loads and maximal running velocity, increased the level of force and the result of such work is increased force in areas of lower loads during higher velocity performance. The variables of muscle force can be seen as a predictor when maximal running velocity is in question since there is connection with running velocity. The domination of maximal force variables in phase of acceleration is shown, while the infuence of velocity of force development variables (RFD) remains disputable in maximal running velocity phase. Key words: INERTIAL LOAD / MAXIMAL RUNNING VELOCITY / VELOCITY OF FORCE DEVELOPMENT / NORMALIZED ISOMETRIC FORCE