Evolution of Key Factors Influencing Performance Across Phases in Junior Short Sprints

Sprint performance plays a crucial role in various sports. Short sprints vary in court size and competitive characteristics but are common in many sports. Although the relationship between age and muscle strength has been explored in short sprints, there is limited understanding of how various physical factors interact, particularly concerning differences in the acceleration phase. This study examined the relationship between sprint times at 0–2.5 m, 2.5–5 m, and 5–10 m intervals and various factors in junior athletes. Results indicated that sprint timesincreased with age, and is correlated with muscle strength and flexibility. Partial correlation analysis showed that faster times in the 0–2.5 m interval were associated with higher hip flexibility; in the 2.5–5 m interval, faster times were associated with higher core flexibility; and in the 5–10 m interval, a relationship with standing long jump performance was confirmed. Furthermore, lower fat-free body weight translated to higher performance. In the acceleration phase of 10 m, flexibility immediately after the start and the subsequent horizontal propulsive force is important factors that are strongly related to performance change in each interval. The study results illuminate the mechanism behind short sprints in junior athletes and emphasize the importance of daily training, considering the sprint distance required for each sport.