INTRODUCTION: From the perspective of physiology, it is very hard to increase velocity in crosscountry skiing. We assume perspective to increase velocity via the efficient use of the power of active energy metabolism, namely increase of mechanical efficiency and propulsive effectiveness of the technique of cross-country skiers. METHOD: The study took part 10 male cross-country skiers from Russia the aged 16-18 years. The main method of our study was the one of additional resistance (Chikov, Chikova, Ryabchenko, Kudrin, 2011). The method of athlete's additional resistance is as follows: a skier passes a 120- meter long part of the distance at maximum velocity (skate skiing). The time (Vmax1) is registered on the 70-meter long control segment (between 70 and 120 m). Then the athlete is attached to the additional resistance body and passes the same distance at maximum velocity once again (Vmax2). The following parameters were obtained after the test: total external mechanical power (Ptomax, W), useful mechanical power (Puamax, W) and propulsive efficiency coefficient (epmax, %). DISCUSSION: In the examined period, velocity increases owing to total power. This is a good thing aside from the propulsive efficiency decrease, i.e. technique changing for the worse. It prevented skiers from reaching higher speed, perhaps it was due to the fatigue accumulated by the end of the competitive period. Moreover, the decrease of propulsive efficiency is assumed to be caused by a sharp increase in mechanical power. CONCLUSION: Propulsive efficiency of the technique changes significantly in the competitive period within a relatively short period of time, the increase in speed is mainly due to the total external mechanical power increase. Proper control of propulsive efficiency will help significantly increase running speed without forcing functional capabilities. We are going to examine this phenomenon in more detail in our next research, as we think here we have a potential to increase running speed, protect athletes' health and optimize the training process. --- The hosting University of Jyväskylä is planning to publish conference proceedings "Science and Nordic Skiing III". In case you are interested in this publication please contact the editors (Anni Hakkarainen anni.s.j.hakkarainen@jyu.fi) to become registered for the book.
© Copyright 2015 3rd International Congress on Science and Nordic Skiing - ICSNS 2015. 5-8 June 2015, Vuokatti, Finland. Veröffentlicht von University of Jyväskylä; University of Salzburg. Alle Rechte vorbehalten.