A force-velocity (F(v)) relationship is specific for single sports. It depends on muscles involved into the movement, technique, media in which the movement is performed, as well as on individual athlete inside specific sports discipline. This relationship enables to establish the model characteristics of an athlete and the effects of sports training. The aim of the project is to define F(v) in some of the sports disciplines (swimming, sprinting) and to analyse the differences among the athletes from those sports.