(60) Longitudinal Changes in Physical Characteristics, Motor Abilities, and Game Performance in Youth Male Basketball Players Based on Biological Maturity.

Purpose: Differences in biological maturity affect the physical and physiological development of youth athletes. However, the effects of these differences on match performance remain unclear. This study aimed to examine longitudinal changes in physical characteristics, motor ability, and game performance of youth basketball players based on biological maturity. Methods: Thirty-one youth male basketball players participated in this study. Participants were categorized into two groups based on the difference between their predicted age at peak height velocity (APHV) and chronological age (CA) at baseline: the post-PHV group (CA >APHV, n=18, CA: 13.5±0.6 years, APHV: 12.5±0.7 years) and the pre-PHV group (CA< APHV, n=13, CA: 12.8±0.3 years, APHV: 13.4±0.4 years). Physical characteristics were assessed via height and body weight. Motor abilities were evaluated through 20-m sprint time, change-of-direction (COD) deficit, countermovement jump (CMJ), and isometric leg extension force (LEF). Game performance was measured using an IMU, including distance traveled and the number of events (sprints, COD, jumps). Measurements were conducted in July 2024 (baseline) and January 2025 (six-month follow-up). A 2 (groups) ×2 (measurement times) repeated-measures ANOVA analyzed biological maturity-associated changes in physical characteristics, motor abilities, and game performance over six months. Results: The post-PHV group had greater height and body weight than the pre-PHV group (height; p< 0.001, η²_p=0.607; p< 0.001, η²_p=0.862, body weight; p< 0.001, η²_p=0.721; p< 0.001, η²_p=0.681). Both groups showed significant increases over six months. There was a significant interaction for height (p=0.005, η²_p=0.243) but not for weight. The post-PHV group had significantly better 20-m sprint time and CMJ than the pre-PHV group (p=0.015, η²_p= 0.208; p=0.010, η²_p=0.226), but no significant change over time. No significant differences were observed for COD deficit or LEF. The pre-PHV group covered greater distances during games than the post-PHV group (p< 0.001, η²_p=0.383). At 6 months, the distance traveled by the post-PHV group increased (p=0.027, η²_p=0.175). The pre-PHV group had more sprints frequency at baseline (p=0.021, η²_p=0.187), but this difference disappeared after six months. COD frequency was higher in the pre-PHV group (p=0.025, η²_p=0.179). Jump frequency increased significantly in the post-PHV group after 6 months (p=0.025, η²_p=0.179). Conclusions: Longitudinal changes in game performance differed from the development of physical characteristics and motor abilities based on maturity level. Practical Applications: Coaches should consider both the degree of development of motor abilities at different maturity levels as well as game performance when designing training programs for youth basketball players. Acknowledgements: This study was supported by a grant from JSPS KAKENHI (JP24K20612). The authors thank all the athletes who participated in this study. No potential conflicts of interest were reported by the authors.