# Profile of Accelerations and Decelerations in Young Basketball Players
## 4 Discussion
These results further highlight the superior acceleration and speed capabilities of perimeter players (Guards and Forwards). These results are consistent with those found by [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [3], confirming that Guards and Forwards show better acceleration performance and reach higher maximum running speeds than Centers. Physical and anthropometric differences are inherent between specific positions, especially between interior and exterior players [54; 55]. Smaller players have lower body mass, making it easier for them to accelerate than for larger players [19]. Additionally, Guards and Forwards have to cover more longitudinal and horizontal distance due to game demands, while the activity of Centers is more restricted to spaces near the rim [15]. When analyzing the differences by playing positions by match period, differences have been identified between all players and periods only in the thresholds of High ACC and High DEC (>4 m\(\cdot\)s\({}^{-2}\)). For Guards, differences were only identified in final speeds between the first and fourth periods. The high-intensity demands of Forwards were differentiated between the first and second periods compared to the third and fourth periods in the distance covered and the exit speed between the first and fourth periods. Similarly, these players decelerated differently between the first period and the second and fourth periods. Finally, Centers showed differences between the first and the rest of the periods in the distance covered with ACC \(>\) 4 m\(\cdot\)s\({}^{-2}\) and the final speed. Additionally, these players performed decelerations differently between the first three periods compared to the fourth in the distance covered and the initial braking speed. During the first quarter, actions are carried out at higher intensity than during the second half of the game [10; 23; 56]. [PERSON] et al. [57] highlighted the differences by playing positions in the physical demands during game quarters in professional players, suggesting the need to take these differences into account to optimize individual and team performance. The demands of repetitive high-intensity accelerations and decelerations seem to take a cumulative toll on the physiological and neuromuscular function of players. The decrease in acceleration capacity over the course of a game may be the result of energy depletion, metabolite accumulation, muscle damage, and central nervous system fatigue, factors that may contribute to the deterioration of acceleration capacity [58; 59]. Developing greater resistance to fatigue through training may help delay performance decline. The results show greater variability in the response of Forwards and Centers in their demands above 4 m\(\cdot\)s\({}^{-2}\) for both ACC and DEC. During the first game periods, intensities are higher compared to the last period. Guards are the players who behave the same throughout the game. The specific external load demands by playing position have been evidenced in numerous studies [21; 22; 32]. Personalization of training in basketball should be carried out because players have unique physical and physiological characteristics, as well as different levels of skill and athletic ability. The game demands that players perform specific technical-tactical actions of their role [4; 60], which is reflected in the physical response during games [2; 8; 47]. Together, these findings provide new insights into how acceleration capacity decreases in different playing positions as fatigue accumulates during competition. Although all players experienced decreases in accelerometry performance, the earlier and more pronounced decreases in acceleration distance and speed in Centers and Forwards compared to Guards suggest that they may be more susceptible to fatigue during games. Specific training for these positions could focus on improving repeated sprint ability and metabolic conditioning.