Millet G Y, Hoffman M D, Candau R B, Clifford P S
Department of Physical Medicine and Rehabilitation, Medical College of Wisconsin, Milwaukee, USA.
Med Sci Sports Exerc. 1998 Nov;30(11):1637-44. doi: 10.1097/00005768-199811000-00013.
A substantial proportion of the propulsive forces required for uphill skiing are generated from the upper body, but no study has systematically examined poling forces at different slopes. In the present experiment, poling forces and timing were examined during roller skiing on 2.1% and 5.1% uphills.
Nine highly skilled cross-country skiers roller skied at paced submaximal and at maximal speeds using the V1 skate (V1) and double pole (DP) techniques. Poling forces and timing were measured with piezoelectric transducers.
Peak force (PF), average force (AF) and average force over the entire cycle (ACF) were significantly greater (P < 0.01) at the steeper grade with both techniques. Values for the ratio of V1 to DP did not differ between the two grades for PF, AF, and ACF but tended to increase with velocity for both techniques. With both V1 and DP, upper body recovery time was shorter (P < 0.01) at the steeper grade, and cycle rate was greater (P < 0.01) at the steeper grade.
We conclude that 1) the relative demands on the upper body with V1 compared with DP were similar between the two grades, and 2) the responses to an elevation in grade of increased poling forces, shortened poling recovery times, and increased cycle rate are comparable to the responses to an increase in speed.
上坡滑雪所需的很大一部分推进力由上半身产生，但尚无研究系统地考察不同坡度下的撑杆力。在本实验中，研究了在2.1%和5.1%的上坡进行轮滑滑雪时的撑杆力和时机。
9名技术高超的越野滑雪者使用V1滑行（V1）和双杖（DP）技术，以亚最大配速和最大速度进行轮滑滑雪。使用压电传感器测量撑杆力和时机。
两种技术在下坡坡度更大时，峰值力（PF）、平均力（AF）和整个周期的平均力（ACF）均显著更大（P < 0.01）。两种坡度下，PF、AF和ACF的V1与DP比值无差异，但两种技术下该比值均随速度增加而趋于上升。使用V1和DP技术时，在上坡坡度更大时，上半身恢复时间更短（P < 0.01），蹬冰频率更高（P < 0.01）。
我们得出结论：1）在两种坡度下，与DP相比，V1对上半身的相对要求相似；2）对上坡坡度增加的反应，即撑杆力增加、撑杆恢复时间缩短和蹬冰频率增加，与对速度增加的反应相当。
