###### Abstract  
This study investigated the impact of consecutive basketball games on the physical demands and well-being of young players under 18 years old (U-18), focusing on the peak demands (PD). Monitoring 17 players over 10 games (5 weekends), external load expressed as relative distance (RD) (m\(\cdot\)min\({}^{-1}\)), high-speed running distance covered (HSR) (m\(\cdot\)min\({}^{-1}\)), maximal accelerations (ACC) (n\(\cdot\)min\({}^{-1}\)), and maximal decelerations (DEC) (n\(\cdot\)min\({}^{-1}\)) normalized by playing time were assessed, and the Hooper index was used to evaluate wellness status. Additionally, linear mixed models and generalized linear mixed models were employed to detect differences, revealing a significant decrease in RD\(\cdot\)min\({}^{-1}\) (F = 4.71, \(p\) = 0.04) during the second back-to-back game. ACC\(\cdot\)min\({}^{-1}\) also exhibited significant differences (\(\chi^{2}\) = 6.44, \(p\) = 0.01) between players in one or two games. However, the PD remained unchanged. Conversely, the Hooper index significantly improved between games (2.67 arb. u. [95% CI 0.11-5.24]), \(p\) = 0.04, d = 1.25 large), indicating enhanced well-being on the second competition day. Although RD\(\cdot\)min\({}^{-1}\) differences suggest the onset of residual fatigue, U-18 teams seem to adapt correctly to a two-game schedule through player auto-regulatory pacing and squad rotation. The positive change in wellness on the second day suggests a need for a comprehensive approach to assessing basketball performance. external load; Hooper index; game analysis; congested schedule +
Footnote †: journal: Applied sciences
basketball players' physical demands during congested schedules is critical to enhancing the training process to optimize players' performance during the competition [3]. Previous scientific research on basketball shows that semi-professional players present similar absolute and relative physical demands (e.g., player load, accelerations) when playing back-to-back games compared to playing only one game per week [4]. However, an increase in the likelihood of injuries in the NBA was observed when back-to-back away games were studied, and negative performance was noticed when the teams traveled [5]. In the case of under-18 (U-18) players, non-significant differences have been reported for average physical demands after playing multiple consecutive games during tournaments [2]. In these cases, the averages of external load variables have been the most used during training and competition [4; 6]. However, peak demand (PD), defined as the most intense activity experienced by players for a selected variable across a specified timeframe of interest, has emerged in recent years as a metric of interest to researchers because it can be helpful to complement traditional average values when aiming to examine and understand the physical demands [7]. Comparing both methods, the exclusive use of averages in team sports could result in underestimating the PD of match-play [8]. While it seems that average physical demands are not significantly reduced during congested schedules in basketball [2], it is still controversial if the PDs of basketball are similarly reached in the second back-to-back game. Although back-to-back games tend to elicit similar average game physical demands (e.g., distance covered, accelerations, etc. ), basketball players have reported a significant decrease in subjective well-being status before the second game [9]. Specifically, the Hooper index is a subjective four-parameter questionnaire (stress, fatigue, sleep, and delayed-onset muscle soreness) [10] which has shown a correlation between neuromuscular fatigue in team sports and athlete-reported fatigue [11]. A method might help monitor basketball players' well-being due to easy implementation [12]. To the authors' knowledge, no research has examined back-to-back games using physical demand values from LPS and well-being data in U-18 basketball players.