抄録
We analyzed the skating trajectory and velocity in men’s 1,500-m and 5,000-m races in a speed skating international competition using a local position measurement (LPM) system. The aim was to identify the characteristics of these races and the association with skaters’ performance. Twenty-five 1,500-m contestants and 31 5,000-m contestants were captured at 60 frames/s with the LPM system, which can automatically identify the top of a skater’s head using 28 cameras mounted on the ceiling of the skating oval and a template matching method. Excess distance was defined as the difference between the actual distance, which was calculated by summing the travel distance at every frame, and the shortest course distance. The change in velocity was calculated for the straight and curve, respectively. The excess distance per lap was over 4 m in both the 1,500-m and 5,000-m races, and was mostly attributed to the curve. In addition, the individual variability of excess distance was large enough to replace the rank. The excess distance in the curve may not always be derived from inadequate centripetal force because some skaters passed more than 0.5 m away from the inner line, not only in the approach and exit from the curve, but also in the middle of the curve. In the 1,500-m race, skaters generally decelerated on the straight, and maintained velocity or accelerated on the curve. On the other hand, all 5,000-m contestants decelerated on the straight and accelerated on the curve. The decrease in velocity on the straight was significantly correlated with the decreased rate of the pace and the official time in the 5,000-m race (p<0.05). The results indicate that a smaller decrease in velocity on the straight was important in maintaining the lap time and achieving superior performance in long distance events.
