INTRODUCTION: While previous investigations indicates that cross-country (x-c) skiers repeatedly perform well above peak aerobic power, even during longer races (for ref., see Saltin, 1997), we have shown that high-level female Juniors are unable to ski at intensities close to their VO2max or maintain an average intensity above that corresponding to their onset of blood lactate accumulation (OBLA, 4 mmol L-1) even during races lasting less than 25 min (Weide et al., 2003). However, this has not been examined in elite x-c skiers and, thus, the aim of this study was to measure VO2 and blood and muscle lactate concentration during x-c skiing at competition speed in male elite skiers and to compare these entities to the subjects' VO2max and the VO2 corresponding to the OBLA during skiing. METHOD: Eight male elite skiers with a mean VO2max of 84 mL kg-1 min-1 served as subjects in four tests: examination of the VO2max and the VO2 corresponding to the OBLA during uphill x-c skiing in the classical and free technique, and a 10-km simulated x-c ski race using both styles. RESULTS: The VO2max and VO2 at OBLA measured during uphill skiing did not differ between the two skiing styles. During the simulated competitions, the VO2 averaged -92% of the VO2max found for uphill skiing, corresponding to exercise slightly above the OBLA. The highest VO2 during the races represented -94% of the skiers VO2rnax. Both the blood and muscle lactate concentration rose quickly during the initial phase (500 m) of the race, before the values levelled off and remained almost unchanged during the rest of the race. The average blood lactate concentration at race speed was 7.7 ± 0.2 mmol L-1, while the corresponding value for the muscle lactate concentration was 11.3 ± 0.3 mmol kg-1 wet muscle mass. DISCUSSION: The skiers' VO2 was high throughout the two races, with no differences between the skiing styles. The skiers were not able to fully use their maximal VO2 during skiing at race speed; the average VO2 was slightly above their OBLA when O2-data from the short pit-stops, and during downhill skiing, were excluded. Both the blood and muscle lactate concentration raised quickly during the early stage of the race in both styles, and remained moderately high during the entire race. This suggests that the exercise intensity may be higher than the skiers' OBLA during skiing at race speed. However, the fact that both the blood and muscle lactate concentration rose considerably less later during the race, may support that the exercise intensity is quite near the elite skiers' OBLA. CONCLUSION: Even elite skiers are unable to ski at exercise intensities at or near their VO2max during a 10 km race, but they may be able to maintain exercise intensities slightly above a VO2 corresponding to their OBLA. Thus, training at exercise intensities near the OBLA may be a training target for x-c skiers.
© Copyright 2010 Book of Abstracts. 5th International Congress on Science and Skiing, Dec. 14 - 19, 2010, St. Christoph am Arlberg. Veröffentlicht von University of Salzburg, Interfakultärer Fachbereich Sport- und Bewegungswissenschaft/USI. Alle Rechte vorbehalten.