著者
谷中 拓哉 中里 浩介 藤田 善也 石毛 勇介
出版者
一般社団法人 日本体育学会
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
pp.18050, (Released:2019-03-18)
参考文献数
23

Cross-country skiers perform over a long distance using poles and skis. Physical fitness, in terms of factors such as VO2max and muscle strength, skiing technique and race strategy are important for winning competitions. To plan the race strategy, investigations of the course profile and race analysis are needed. The purposes of this study were to investigate cross-country skiing course profiles which were planned for the Winter Olympic Games at Peyongchang, and to analyze the men’s 15km+15km World Cup skiathlon race (SA) as a pre-competition event. A cross-country skier followed the classical and skating courses using a GNSS (Global Navigation Satellite System) antenna. The antenna instantly measured the latitude, longitude and height of the skier on the courses. The coordinate values on a plane were calculated from latitude and longitude, after the inclination was then calculated from the coordinate values and height every 10 m. The overall finish time and transit time at 24 points for 12 skiers in SA were retrieved from the Official Home Page of the International Ski Federation (FIS), and the segment times among the various points were calculated. Three segment times formed a lap, and each segment speed was calculated by dividing the segment distance by the segment time. For the classical course profile, the distance was 3819 m and the maximum inclination was 18.6%. In contrast, for the skating course, the distance was 3777 m and the maximum inclination was 20.6%. No correlation was found between the overall finish time and the segment times for the classical course. This result was attributable to small variations in the lap times for the classical course because of the skiers’ use strategy, checking among competitors, and the mass-start. On the other hand, positive correlations were found between the overall finish time and the segment times on skating. In skating, the segment speeds from the final phase of the 2nd lap to the middle phase of the 3rd lap indicated deceleration relative to the 1st lap. These results suggest that gliding on a skating course in a short time is important for shortening the overall finish-time. Especially, it is important to minimize the deceleration of the 2nd and 3rd lap segment speed. The race pattern for the Olympic Games was similar to that of pre-competition, except for the time taken. These results indicate that pre-competition race analysis is useful for devising a strategy for target competition.
著者
藤田 善也 石毛 勇介 吉岡 伸輔 竹田 正樹
出版者
一般社団法人 日本体育学会
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
pp.13047, (Released:2014-01-23)
参考文献数
10

The purpose of this study was to evaluate the relationships between race performance and cycle characteristics in a 10-km classic-style men's cross-country ski competition. The subjects were competitors in the 89th Japan National Ski Championships. Skiing motions of the subjects on flat stretches (1.5 km and 6.5 km) and uphill slopes (1.7 km and 6.7 km) were videotaped using two high-speed cameras. Cycle characteristics were calculated based on measurement of hip displacement and cycle time. It was revealed that elite competitors (1) performed at high velocity at all measurement points, (2) reduced their velocity in the last half of the race, (3) achieved a high velocity in double poling and diagonal stride, (4) increased their cycle length and cycle rate when employing the double poling technique, and (5) increased their cycle length when employing the diagonal stride technique.