The annual changes and differences in the physical performance characteristics of sports school students

Sports schools provide an environment that foster both academic and sporting excellence in youth athletes, yet physical performance during adolescence is strongly influenced by biological growth and maturation. High intensity actions such as sprinting, jumping and changing direction are important in many sports, particularly team sports, but how these characteristics develop across the school year remains unclear, especially in mixed-sex populations. This study explores the seasonal variations in physical performance across an academic year within a sports school, accounting for biological maturation status and sex. A total of 337 different student athletes between the ages 9–19 years (14.10 years ± 1.93) completed anthropometrics assessments, maturity estimations (percentage predicted adult height) and performance testing (20 m sprint, countermovement jump, Pro Agility and 30-15 IFT) at up to ten testing dates across four year (2021–2024). Performance increased with both chronological age and biological maturity in both sexes. In males, sprint, agility, and jump performance increased progressively across age groups, while females demonstrated significantly lower performance at U12 compared to all other age groups yet few differences after that except in 20 m sprint. Females saw maturational differences between pre- and post-PHV in all tests. A significant interaction between test date and maturity was evident in males for CMJ and VO2max yet only a small effect size was evidenced. These findings highlight the importance of tracking sex specific and maturity related changes across the academic year to appropriately support training prescription, particularly in female athletes who may require more targeted developmental opportunities.