• S.E. Humphreys


The purpose of this investigation was to determine the kinetic poling patterns of elite level cross-country skiers performing the V2 skating technique on roller skis. Five male United States Biathlon Developmental Team members from the Olympic Education Center in Marquette, Michigan, volunteered as subjects for this investigation. Subjects performed three paced roller ski trials using the V2 skating technique at 4.7 m/s , 5.8m/s, and 6.7m/s, which represented slow, race, and sprinting paces, respectfully. Piezoelectric load cells mounted within the shaft of each ski pole were used to determine axial poling forces for each trial. Raw voltage signals from the conditioned load cells were stored in a specially designed portable data logger with programmable capabilities. After each trial, data files were downloaded to an on-site microcomputer and stored in binary format. The binary data files were fbrther processed and used to determine cycle duration (CD), cycle impulse (CI), average cycle force (CF), and peak cycle force (PF). Values from each variable were averaged over two consecutive poling cycles and compared for statistical significance with one-way repeated measures ANOVA. Mean values are summarized below. . For the three velocities examined, CD was the only observed variable found to be statistically different (p<0.05). In contrast, mean values between race and sprinting paces were almost identical for CF (94.6±23.3 vs. 95.6± 25.6) and PF (360.0±71.6 vs. 359.2 ±141.4). Based upon the results of this study, it appears that the primary means by which a skier controls velocity is through manipulation of cycle rate (i.e., increasing or decreasing cycle duration) with little or no change in CF or PF at the faster paces. Practical application of these results would suggest that skiers wishing to maximize velocity should place an emphasis on increasing cycle rate, as opposed, to applying a greater amount of force with the upper torso. This project was funded in part by a Spooner Research Grant.




Coaching and Sports Activities