## 1 Introduction
[PERSON], [PERSON], and [PERSON] [11] investigated the correlation between horizontal jumps (SLJ, five jumps from standing (S5J)), ten jumps from standing (S10J)) and kinematic parameters and sprinting times on specific segments of 100 m (10 m, 30 m, and 100 m) using competitive sprinters and student athletes. The study results showed a high correlation between all three tests and the 10 m sprint run (start and start acceleration), the 30 m sprint run (acceleration), and the 100 m sprint run (maximum running speed). The correlation coefficients ranged from r = \(-\)0.66 to r = \(-\)0.88, but, as the authors noted, these correlations were characteristic only of the sprinter group, not the student-athlete group. Available research studies lack data on unilateral cyclic horizontal jumps measured in units of time, with the exception of the studies by [PERSON] et al. [26], [PERSON] [27], and [PERSON] et al. [28] in rehabilitation after the knee injury. Using a large sample of girls, [PERSON] [27] tested differences between gifted and less gifted girls in the 60 m sprint running. Among other tests, [PERSON] used the test of 30 m unilateral horizontal cyclic jumps (UHCJ30m). The time and number of jumps along the 30 m distance using the left and right leg contribute to the discrimination of gifted and less gifted girls in the 60 m sprint running. The author stated that the UHCJ30m test should be adapted for this age group considering the psychophysical characteristics of children of this age and that the test distance should be shortened. The UHCJ30m test is similar to the UHCJ20m test validated by [PERSON] et al. [26] in their research study of student athletes. The authors [26] state how the composite measuring instrument (UHCJ20m) has a high reliability (Cronbach \(\alpha\) = 0.95, ICC = 0.94), a high homogeneity (AVR = 0.88), and they state how the test has satisfactory sensitivity. Horizontal jumps showed greater correlation than vertical jumps with specific segments of sprint running [6; 7; 8; 9; 10; 11; 12]. However, some research studies found a correlation between certain kinematic parameters of the vertical jumps CMJ and SJ (power and force) with start and start acceleration (10 m sprint), whereas horizontal jumps showed no statistically significant correlation [29]. The UHCJ20m test is used in sports practice but has not been standardized and validated. To date, there has been no such research, so there was a need for such research to determine the legitimacy of its use in practice and to gain insight into the kinematic parameters of the test and their effects on sprint running performance. The purpose of this research study was to determine the relationship between unilateral horizontal jumps and running speed (sprinting). The aim of this research study was to investigate correlations between kinematic parameters of unilateral horizontal jumps and 20 m running test results from a block start and a flying start, i.e., the start acceleration, the maximum running speed, and the 100 m running result. The hypothesis of this research study was that the UHCJ20m test has a significant correlation with the M100m, MRLS20m, and MRFS20m tests and that a significant correlation exists between some kinematic parameters of the UHCJ20m test with the M100m, MRLS20m, and MRFS20m test results.