AbstractThe aim of this study was to determine the individual and the optimal force-velocity-relationship of athletes during vertical squat jumps and to develop the jump height on the basis of this informations.Eight active sportsmen took part in this study (6 male, 2 female; age: 24,13 3,09 years, height: 1,80 0,09 meter, weight: 74,46 12,6 kilogram). They performed squat jumps with different loads on a force plate. The additional weights were adapted to the body mass of the athletes and so divided into five different units, which corresponded to 0, 12.5, 25, 37.5 and 50% of the body weight of each athlete. Two jumps were made with each loading.By using the method from Morin and Samozino (2017), both the current and the optimal force-velocity-relation, based on a maximal jump performance, of each participant could be determined individually. For this, some anthropometric data (lower-limb length, jump height, body mass), the additional weights and the achieved jump height were necessary. On the basis of these ascertained relations, a individual force-velocity-relation-imbalance (F-v-imbalance) could be determined, which was the basis for the training planning according to Jiménez-Reyes, Samozino, Brughelli and Morin (2017). Based on this recommendations the subjects conducted a six-week training program.On the basis of the targeted training of the subjects, there was a significant increase in the jump height (Pre: 0,45 0,05; 0,41 0,05; 0,38 0,04; 0,35 0,04; 0,32 0,04; Post: 0,47 0,05; 0,43 0,04; 0,39 0,04; 0,35 0,03; 0,33 0,03 meters; p-value: 0,05) at a level of significance of 5%. On the one hand this led to an improvement in the F-v-imbalance (Pre: 173,25 28,07; Post: 153,13 40,52; p-value: 0,05) but a non-significant. On the other hand, a significant improvement was found in the velocity v of the athletes, with no significant changes neither in the force F nor in the maximum power output Pmax (p> 0,05).