抄録
The purpose of this study was to show the tendency of cross-country skiing in Nordic Combined competitions and to discuss the difference in speed between Japanese players and winners within eighth rank based on the physical characteristics of Japanese players. The fourteen 10 km races in 2018-2019 season were analyzed. Overall finish times and transit times for winners and 4 Japanese players were retrieved from official Home page of Fédération Internationale de Ski, and the segment times among the various points were calculated. Average segment speeds were calculated by dividing the segment distance by the segment time. For each race, the speed differences between winners’ average speed and Japanese players’ one was calculated. The subjects performed two exercise tests on different days. First, subjects performed multistage incremental roller-ski test to measure blood lactate concentration (La) and maximum oxygen uptake (VO2max). In another day, they performed roller-skiing on the treadmill where the speed and slope were changed assuming a 10 km race, and the La at the time was measured. In many of the 10km cross-country skiing races at the Nordic Combined, the winners skated at a fast speed in the early stages, narrowing the time difference from the beginning. Furthermore, it was shown that the speed of winners increased in last lap. The top Japanese player, who have won many prizes, was skating at the same speed as the winners, but other players were skating at a slower speed than the winners from the beginning of the race, which was the most prominent on the final lap (p < 0.01). Even though the top Japanese player’s VO2max (65 ml/kg/min) was lower than other players, the indicator showing gliding efficiency was highest (VVO2max: 5.5 m/s). These results suggest that the top Japanese player use energy-efficient gliding methods to suit various situations.
