CeRiSM, University of Verona, Rovereto, Italy.
Neuroscience, Biomedicine and Movement Department, University of Verona, Verona, Italy.
J Sports Sci. 2020 Apr;38(8):863-872. doi: 10.1080/02640414.2020.1736246. Epub 2020 Mar 5.
We aimed to evaluate the changes in double poling (DP) kinematics due to a long-distance cross-country skiing race in athletes with different performance levels. A total of 100 cross-country skiers, belonging to 10 different performance groups, were filmed on flat terrain 7 and 55 km after the start line, during a 58-km classical race. Cycle velocity, frequency and length decreased from the best to the lower-ranked group, while duty cycle increased (all <.001). Between track sections, cycle velocity and length decreased, duty cycles increased (all <.001) while frequency was unaltered ( =.782). Group*section interactions resulted for cycle velocity ( =.005). Considering all the participants together, % change in cycle velocity between sections correlated with % change in length and duty cycle (all <.001). Thus skiers in better groups showed longer and more frequent cycles as well as shorter duty cycles than skiers in slower groups; throughout the race all the groups maintained the same cycle frequency while decreasing cycle velocity and length; better groups showed a lower reduction in cycle velocity. Individually, a low reduction in cycle velocity during the race related to the capacity to maintain long cycles and short duty cycles.
我们旨在评估不同运动水平的运动员在长距离越野滑雪比赛后双支撑（DP）运动学的变化。在 58 公里的经典比赛中，100 名越野滑雪运动员在起跑线后 7 公里和 55 公里处的平地上被拍摄。从表现最好的组到排名较低的组，循环速度、频率和长度都减少，而工作周期增加（均<.001）。在轨道段之间，循环速度和长度减小，工作周期增加（均<.001），而频率不变（=.782）。组*节相互作用导致循环速度发生变化（=.005）。考虑到所有参与者，节间循环速度的变化百分比与长度和工作周期的变化百分比相关（均<.001）。因此，表现较好的组的运动员比表现较慢的组的运动员具有更长和更频繁的周期以及更短的工作周期；在整个比赛中，所有组都保持相同的周期频率，同时降低了循环速度和长度；表现较好的组表现出的循环速度降低幅度较低。个体而言，比赛中循环速度的降低幅度与保持长周期和短工作周期的能力有关。
