Abstract
In ten-week period, junior basketball players divided into two groups, experimental and control, were subjected to various training programs. Experimental group members, in addition to regular technical and tactical basketball training, had additional complex training twice a week, while the subjects in the control group only had a technical-tactical basketball training. The aim of this study was to test the impact of complex training on explosive leg strength in the performance of different jump variants of junior basketball players. Countermovement jump and Squat jump were tested as well as the following variables: maximum jump height (h), maximum force (Fmax) and the time needed for the achievement of the maximum force (tmax) in concentric contraction when performing jumps and explosive strength Index (IES = Fmax / tmax). Comparing the results obtained on the basis of the initial and final measurements, it has been proved that the tested variables have changed under the infl uence of experimental factors. In both tested jumps the maximum jump height (p=.00) and maximum force (p=.00) were significantly improved, whereas IES improved only in the Countermovement jump
(p=.00). the time of the maximum force realization remained unchanged during the ten-week treatment. The research has proven that the complex training has influenced the improvement of explosive leg strength in junior basketball players.