# Profile of Accelerations and Decelerations in Young Basketball Players
## 1 Introduction  
The Addas Next Generation Tournament, ANGT, is a top European basketball competition in the under-18 category. This is considered the highest level of European clubbasketball competition. It is known as the Junior Euroleague. The final phase of this competition is played by eight teams, competing in two groups, and a final game between the two best teams. The high level of play developed in this tournament, serving as a breeding ground for future stars of world basketball, has led to a growing interest in studying player behaviors, both from a physical perspective [1; 2; 3], in terms of player talent development [4], and technical-tactical aspects [5]. Additionally, basketball is a sport that involves high-intensity movements, with explosive and powerful actions, such as jumping for rebounding, shooting, or blocking, or accelerations such as driving, lay-ups or fast-breaks [6; 7]. [PERSON] et al. [8] have identified a high load in the variables related to accelerometry (Impacts and Player Load), stating that in view of these demands, basketball should be considered an eminently neuromuscular sport. During the course of the game, the players experience peaks of high intensity in these variables, which correspond to the explosive game actions that the players perform to overcome the opponents and achieve the objective of the game [9; 10]. Nowadays, micro-technology allows teams and staff to monitor player and competition demands, fostering new frameworks to control training and competition load, increasing players' performance [2] and providing individualized recovery strategies [11]. This technology records information related to External Load (EL) variables, such as distance, speed, impacts, player load or acceleration (ACC) and deceleration (DEC). In fact, accelerations and decelerations have drawn attention in recent years in several studies [12; 13], as microtechnology allows, through the change in the accumulated acceleration in three vectors (x, y and z), the monitoring of loads during training and competition [3]. More importantly, the ability to accelerate and decelerate is paramount for basketball success [14]. Due to the short duration of sprints (0.4 to 2.4 s), accelerations and decelerations play a meaningful role in locomotor demands and in basketball performance [12]. Accelerations and decelerations have been defined as the change in magnitude, both positive and negative, in speed, implying a movement of more than 2.5 m\(\cdot\)s\({}^{-2}\)[15]. Accelerometry has become an important focus in basketball as a means to quantify the external load placed on basketball players [16]. Research has demonstrated the usefulness of accelerometers in providing objective data on movements and physical demands during training and competition in basketball [17; 18; 19]. Accelerations and decelerations account for up to 12% of live playing time across all playing positions [18]. Analyzing accelerometer data allows coaches to determine the acceleration and deceleration demands for different playing positions during live play [20; 21]. A systematic review on this topic organized acceleration and decelerations into total and high-intensity categories, stating that more investigations are necessary on this topic to obtain a clear picture [14]. The importance of individualization in training and match load has been widely stated [22; 23]. In basketball, three playing positions have been identified: Guards, Forwards, and Centers [24; 25]. Differences have been observed for anthropometric and physical characteristics, such as sprint and jumping ability. For example, among men players, Guards are the ones who, when in ball possession, performed more activities across all intensity ranges than Forwards and Centers, although the proportion of time dedicated to performing high-intensity activities (HIA) when in ball possession was greater for Forwards and Centers than for Guards [24].