Heterogeneous developmental trajectories of Chinese male 100-m reserve talents: a latent class growth analysis based on national competition data from 2019 to 2025

Abstract Background The developmental pathways of youth sprint athletes are often assumed to follow a single average trend. This exploratory study aimed to identify distinct growth trajectories among Chinese male 100 m sprint reserve talents aged 18 to 21 years and to describe differences in performance characteristics across trajectory classes. Methods National competition data from 2019 to 2025 from 157 male athletes were analyzed. Annual best performances were converted to velocity. A latent class growth model identified developmental trajectories. Post hoc descriptive comparisons examined differences in early performance, personal best, performance stability, competition density, and region across classes. Results Four trajectories were identified. Three of these were relatively stable: Steady Development (15.9%), High level Steady Progression (66.2%), and Sustained Leading (12.1%). A fourth trajectory, Accelerated Breakthrough (5.7%, n = 9), exhibited a distinct catch up pattern from approximately 11.21s at age 18 to the national elite standard by age 21. However, a leave one out jackknife analysis showed that this class dissolved upon removal of any single constituent athlete, indicating that it lacks statistical stability and should be treated as an exploratory finding. Early performance and personal best showed strong descriptive associations with class profiles. Competition density was higher in classes with better performance. Region was not statistically significant. Conclusions Chinese male sprint reserve talents follow multiple developmental pathways. The Accelerated Breakthrough pattern, though statistically unstable, generates a hypothesis that a small subset of late emerging athletes may exist within the current system. This hypothesis requires independent verification in larger samples before any practical implications can be drawn. The findings are exploratory and hypothesis generating only.