Enhancing speed and efficiency: biomechanical variation in maximal speed double poling among different performance level cross-country skiers

This study aimed to identify biomechanical differences among cross-country skiers with different performance levels at maximal speed using the double poling technique. Methods. Twenty-four cross-country skiers, including 12 national-level and 12 regional-level participants, skied on an 80 m flat snow track. Cycle and joint kinematics data, integral electromyography (IEMG) and root mean square (RMS) data of the muscles, and relative plantar force data were collected. The results showed that national skiers had a greater mean velocity (p < 0.05) and swing length (p < 0.05) and a shorter relative poling time (p < 0.05) than regional skiers. Additionally, the joint angles of the shoulder and elbow at the pole plant were greater in national skiers (p < 0.05) than in regional skiers. The contribution ratio of muscles regarding the gluteus maximus was greater for national skiers than for regional skiers (p < 0.05). National skiers tended to activate muscles at higher levels and transfer higher loads to the front foot during the poling phase. Our findings indicate that it appears advantageous for skiers to lean their trunks forward during the poling phase due to weight utilization, which may increase velocity in the forward direction during the double poling cycle for more efficient use of the body.