Measurement of Head Motion during Double-Poling Technique in Cross-Country Ski Classical Race using Kinematic GNSS

A world-class cross-country ski player was aimed at a men's time race by the classical style at the 5.3 km course at Vuokatti in Finland. A wearable high-precision Global Navigation Satellite System (GNSS) was attached to his head in order to detect sub-technique used during the time race. Double poling is important sub-technique for the classical technique because it is faster than any other sub-techniques. The total performance is expected to be improved by increasing the usage rate of the double poling sub-technique. In this report, we focused on the detection of the double poling sub-technique. From the results of our study, it was suggested that high-precision GNSS can be used effectively to detect double poling sub-technique as well as other sub-techniques of classical style of cross-country ski race. Moreover, we found a certain law required for automatic discrimination of the double poling sub-technique from the vertical movement of the head with respect to the speed which obtained by the high-precision GNSS.