This study was conducted to clarify the relationship between features of change in velocity and performance of world class athletes in the men's 400-m hurdle race(400mH).Nine final races of 400mH were videotaped with several video cameras panning from the start to the finish at 60 fields/s.After the time indication had been superimposed on each field of the VTR images, the time at touchdown immediately after hurdling was obtained.Using the flash of the starter's gun recorded on the VTR image, each hurdle touchdown time from the start, and each section thme(from each hurdle to the next)was obtained.The results of regression analysis showed a significantly high correlation (r=0.90, p<0.001)between 400mH performance and mean section velocity from the 5th to the 8th hurdle(H5-8), and a significant correlation(r=-0.61, p<0.05)between 400mH performance and te rate of deceleration in H5-8.These results indicate that in 400mH it is important to avoid decreasing velocity and to maintain a high velocity in H5-8 of the race in order to attain a high performance.
