Introduction: Evaluation of the F-v profile of the vertical jump has become increasingly common in the diagnostic process, and examination of the effects of targeted training based on this type of assessment has been conducted in several studies up to today. However, by reviewing the literature it has been found that there is no study of the influence of different types of loads on the performance of a bilateral vertical jump examined on subjects of the same type of F-v profile. Therefore, the basic goal of this study was to evaluate the influence of two different types of loads on the performance of squat jumps in subjects deficient in force in the F-v profile. Methods: Eighteen subjects participated in the part of research concerning acute effects. All subjects were tested in two different protocols. One protocol referred to the performance of a half back squat with a load of 85% of one maximum repetition (1RM) and indicated a pre-load in the direction of force. During another protocol subjects performed a squat jump with an unloading of 25% of body weight and that indicated a preload in the direction of velocity. Peak height of squat jump was analyzed during the initial measurement and 1'30 '', 4 ', 6'30' 'and 9' after the pre-load. The set hypothesis was tested with one-way and two-way ANOVA for repeated measurements. A total of thirty subjects, equally divided into two groups, participated in the study of chronic effects. During the seven-week training program, the force group performed a half back squat with a load of 80-85% 1RM, while the velocity group performed squat jumps with an unloading of 25% of body weight during the same period. Differences between initial and final measurements within the protocol were tested by t - test for dependent samples or Wilcoxon signed-rank test. The significance of the interaction of the measurement time factor and the training program was examined with a 2 x 2 mixed ANOVA model. Results: Statistical significance was determined by one-way ANOVA during the pre-load protocol in the direction of velocity, with an emphasis on a significantly lower value of squat jump height at 9' after the pre-load performance in comparison with the initial measurement. In contrast, no significance was observed within the pre-loading protocol in the force direction. The significance of the interaction between the measurement time factor and the preloading protocol was noted with two-way ANOVA, but the Bonferroni test did not find statistical significance between the analyzed pairs. In the study of chronic effects, non-significant changes in all kinematic and kinetic variables of the vertical jump at the velocity group are noticeable. Also, in the mentioned group there were no significant changes in the F-v profile. The group of forces records opposite trends, so in most kinematic and kinetic variables they are of noticeable significance, with an emphasis on improvements. These improvements are accompanied by significant optimization of the mechanical F-v profile. It is worth noting the large effect of the training on the change in the peak height of the squat jump, the peak force of the squat jump and the peak power of the countermovement jump. Medium effect on the change in the peak height of the squat jump with preparation. Additionally, a medium effect on the change in peak height of countermovement jump squat was observed. Conclusion: The results of the velocity group in the study of chronic effects, as well as the results of the pre-loading protocol in the direction of velocity in the study of acute effects, support the hypothesis that dominant performance of stimuli contrary to the deficient component of mechanical F-v profile may cause invariance or even a decrease in performance. The hypothesis of the effectiveness of a training program aimed at developing a deficient component of the F-v profile is largely argued by the results of force group in the study of chronic effects, while recorded acute effects of pre-load in the direction of force show only slight potential for such strong indications.