###### Abstract  
The basic technical element that is a direct response to the opponent's attack is the block. Blocking is related to setting the starting position of the player and choosing the most effective way to move. The aim of this study was to evaluate the time of movement in the block depending on the difficulty of the task determined by a response to light signals. The study included 14 players (17.36 \(\pm\) 1.18 years). Eight discs of the FITLIGHT TrainerTM device placed at different heights near the center of the volleyball court were used for the measurements. The player's task was to move as quickly as possible in a block after recognizing a light signal to take a specific action. Three types of tasks with different levels of difficulty were defined: reaction to the light signal on the player's side (S1), reaction to the light signal of the upper or lower discs placed vertically over the net (S2), and reaction to the color of the light signal of the upper or lower discs placed vertically over the net (S3). The following time measurements were analyzed: indirect time (TI), time of movement to the jumping point (TJP), and total time (TT) on the right and left sides. In all measurements (TI, TJP, TT), the differences in the times obtained in tasks S1 and S2 and tasks S1 and S3 were statistically significant (\(p\leq 0.001\)) for both the right and left sides. The comparison of the task performance times for S2 and S3 showed a difference only in the TJP measurement for the left side. An analysis of the results indicates a significant role of signal recognition and decision-making process in the player's movement during blocking. The FITLIGHT TrainerTM device can be a useful tool for this purpose in coaching. v 2023202327 September 202311 October 202317 October 202317 October 20231  
of the net regardless of where the ball is set from. The behavior of blocking players can also be divided into a read-and-react playing strategy and an anticipation movement game strategy [5; 8]. In the first strategy, players move to the block only in response to the set ball. In the anticipation movement strategy, players establish ready solutions even before the opposing team starts the action. This manifests itself by setting up a block in a specific zone of the court even before the ball is set. The starting positions of the blockers can also be aimed at the better organization of the block in specific zones of the court and influence the opponent's action. The pinched (near the center player), spread (near the sideline), or mixed (narrow on one side and wide on the other) positioning of opposite hitters translates into the distribution of balls set by the opposing team's setter [9]. Consequently, blockers can reduce the effectiveness of the opponent's best actions and make it necessary to play using other variants. Based on the offensive tactics of the opposing team and the setting direction and tempo, different systems and strategies of block play can be distinguished. One of the objectives of previous research assessing the quality and effectiveness of a volleyball block is distinguishing the different ways in which the player moves from the starting position to the jump position. Research shows that when moving on the court, athletes use a slide step, a cross-over step, or a running step, and various combinations of slide and cross steps [10; 11; 12; 13; 14]. The means of movement are determined by the player's specialization, individual preferences, training experience, and the zone of the court in which the block is performed [12; 14]. One of the main elements explored in previous studies was the speed of movement of the various techniques. Research [14] showed that although as many as four means of performance can be defined in the cross-over step, they do not differ significantly in terms of the speed of performance. However, it has been observed that in the first phase, the most effective method is the cross-over step, consisting of two steps.