Training at a specific movement tempo is a relatively new concept in resistance training. It is based on manipulation of the duration of particular phases of a movement. General studies have demonstrated that faster movement tempo in resistance training leads to an increase in muscle power, whereas lower movement speed is beneficial in the development of muscle strength and hypertrophy. However, the studies in this area are inconclusive and do not relate precisely to various tempos and movement speeds. The aim of the study was to determine the effect of duration of the eccentric cadence ECC (2/0/X/0) and ECC (6/0/X/0) on muscular power generated in the concentric phase of the movement expressed in maximal P, V and average values P, V For the ECC (6/0/X/0) cadence, a significantly lower value of P (401.95 ± 65.42 W) was observed compared to the ECC 2/0/X/0 tempo (467.65 ± 79.18 W), at p = 0.007. The same was true for power evaluated in maximal values (P), as significantly higher values were recorded for the regular ECC (2/0/X/0) (671.55 ± 115.79 W) compared to the slow tempo ECC (6/0/X/0) (565,70 ± 117,37 W), at the level of significance of p = 0.007. The velocity evaluated for ECC (2/0/X/0) tempo expressed in average values (V) 0.60±0.09 m/s was significantly higher compared to the ECC (6/0/X/0) tempo (0.52 ± 0.08 m/s), with p=0.004. When maximal velocity (V), was considered higher values for ECC (2/0/X/0) tempo was registered (0.79 ± 0.10 m/s) compared to the ECC (6/0/X/0) tempo (0.69 ± 0.13 m/s), at significance of p = 0.001. The main finding of the study indicates that the duration of the eccentric phase of the movement has a significant impact on muscular power and velocity during the concentric phase of the movement.