摘要:The purpose of this study was to describe the characteristics of fast race horses by analyzing the running form of Deep Impact, the undefeated Japanese triple crown winner in 2005. A high-speed video data of the Kikuka Syo race (Japanese St. Leger, JPN G1, 3,000 m, turf) was taken at a rate of 250 frames/sec. The high-speed video system was set in a left lateral position about 100 m before the finishing post with a field view width of about 16 m. The speed of Deep Impact, 17.8 m/sec, was the fastest of all horses measured (average 16.1 m/sec), the stride frequency, 2.36 strides/sec, was the third largest (average 2.28 strides/sec), and the stride length, 7.54 m, was the longest (average 7.08 m). The diagonal and airborne step lengths of Deep Impact were longer than the average values. The overlap time of Deep Impact was shorter than the average value. The ratio of overlap time to stride duration of Deep Impact was 8.5 %, whereas the average value was 16.9 %. A shorter overlap time was also observed on a common characteristic of Secretariat, the famous elite race horse in USA and correlated to running speed. Thus, these characteristics may be related to effective running form in elite horses.