日本陸上競技学会

村冨 浩太朗，今泉 堅貴，後岡 直樹，古橋 侑季，谷川 聡，前村 公彦

Vol.24, 2026

This case study aimed to elucidate the multifactorial determinants that contributed to the improvement of 400-m sprint performance in an elite Japanese sprinter through a longitudinal analysis of race patterns, energy efficiency, and associated training processes. The participant, a nationally top-ranked 400 m runner, substantially improved his personal best over the course of one year (2022–2023), recording a time of 45.54 seconds—ranked fifth in Japan at the time. Race analysis revealed that, in 2023, the rate of velocity decline after the 150-meter mark was smaller compared to 2022, allowing the athlete to maintain speed into the latter stages of the race. Additionally, results from a supramaximal constant-load test indicated a transition toward a more efficient running form, characterized by the generation of longer strides with reduced mechanical work. These findings suggest that the suppression of mechanical workload during the early phase of the race may have contributed to conserving energy and maintaining speed in the latter half. Notably, the athlete had consistently engaged in training programs aimed at enhancing running efficiency throughout this period, which also accompanied observable changes in movement patterns and attentional focus during sprinting. Collectively, these findings provide practical implications for the development of effective training strategies to enhance 400-meter performance in elite-level sprinters.

－力学的エネルギーおよびレースパターンの変化に着目して－