Kinematics of sprint cross-country skiing.

The purpose of our study was to characterise the diagonal stride locomotion during a new short sprint race in cross-country skiing. Thirty male cross-country skiers were sagittaly filmed on an uphill portion of the 1.2-km classic race of the world cup (2004) using a digital camera. The main body joints, skis and poles were digitised frame by frame. Results indicated higher SV and SR for similar SL compared to longer distance races with a similar slope. Moreover, significant correlations were observed between SV and SR but not between SV and SL contrary to the other distance races. SL results showed that in spite of the high SR, skiers maintained an effective leg and pole thrusts. The high SR in KO sprint presented a mechanical advantage by minimising the decrease of velocity during the cycle. The importance of SR in the velocity production could be useful for practitioners to optimise the training program for this type of race. It seemed notable that the skiers had to improve temporal factors while conserving a long SL.