## 2 Materials and Methods
### Testing Procedure  
Six tests were applied in this study to evaluate the agility of basketball players: T agility test, T agility test with ball, reactive T agility test, reactive T agility test with ball, Illinois agility test, and Illinois agility test with ball. All study groups--experiment and control (U14 and U16)--were evaluated through all 6 tests and under the same test conditions regarding the order of their performance, the number of trials (two trials were performed for each test and the best result was quantified), and the test period. The Fitlight technology was set the same for testing all groups. * T Agility Test (standardized): This test required participants to perform a series of quick movements in a 'T'-shaped pattern as described in Figure 1a. It was designed to evaluate their agility and speed without the use of any additional equipment and the tests validity for determining agility was approved by scientific research [40]. The athletes were timed (s) according to their ability to quickly perform the test in relation to the speed of foot execution and coordination ability. This agility test is very effective for basketball athletes due to the similarity between the test design and fundamental basketball movements [41; 42]. * T Agility Test with Ball: Similar to the T agility test, this variation added the complexity of dribbling a ball. Participants were required to maneuver through the 'T' pattern while maintaining control of the ball, testing their coordination between movement and ball-handling skills. This test is especially important since lateral dribble and dribbling the ball while moving backwards are important parts of basketball. The athletes were timed (s) according to their ability to quickly perform the test. * Reactive Agility T Test: This test incorporated the use of a Fitlight system placed on cones, like seen in Figure 1b. Athletes had to quickly react to light signals, rapidly changing direction in response. This version of the T agility test focused on the participants' reaction time and agility, assessing their ability to respond to visual cues under time pressure. The Fitlight technology was set so that when the second spot (in the middle) is touched, randomly, one of the two spots arranged at the ends of the T, which indicates the direction of further travel, automatically lights up. Many researchers have studied reactive agility and developed new tests to measure it [14; 43; 44]; however, our distinctive way of modifying a standardized test by integrating Fitlight technology adds significant value to the field of research of reactive agility. The athletes were timed (s) according to their ability to quickly perform the test. -- Reactive Agility T Test with Dribbling: Building upon the reactive agility T test, this test added the element of dribbling. Athletes were tasked with responding to the Fitlight signals while controlling the ball. The Fitlight technology was set so that when the second spot (in the middle) is touched, randomly, one of the two spots arranged at the ends of the T, which indicates the direction of further travel, automatically lights up. This test challenged their ability to combine agility, reaction time, and ball-handling skills under dynamic conditions. The athletes were timed (s) according to their ability to quickly perform the test. -- Illinois Agility Test (standardized): This is a classic assessment that involves a series of quick turns and sprints around a rectangular formation. It measures the participants' agility, speed, and flexibility, requiring them to perform the course in the shortest possible time. Research has demonstrated the effectiveness of this test in determining the agility levels of male team sport players [45]. The athletes were timed (s) according to their ability to quickly perform the test. -- Illinois Agility Test with Ball (standardized): Athletes performed the Illinois Agility Test while dribbling the basketball (Figure 2).