INTRODUCTION: A significant anaerobic contribution is expected in sprint skiing. Anaerobic energy production during supramaximal exercise has been estimated from the accumulated oxygen deficit (AOD) method in different sports, but not in cross-country skiing. We wanted to use the AOD method to estimate the contribution of aerobic and anaerobic energy sources during a cross-country sprint leg. METHODS: Twelve elite senior male cross-country skiers participated in the study (24.2±3.1 yrs, 183.1 ±5.0 cm, 78.7±6.8 kg, V2 VO2max; 72.6±2.5 ml-kg-1-min-1/5.7±0.5 L.min-1). Three submaximal trials (4-6°) and one performance test (7°) were performed in the V2 ski skating technique on a large rollerski treadmill. Oxygen consumption and heart rate (HR) were measured continuously during the tests and blood lactate concentration 30 s after each bout. At the performance test the skiers should complete 600 m as fast as possible (self selected speed). Accumulated (acc) O2-demand was estimated by extrapolation of the linear relationship between the power and the O2 demand established at submaximal loads for each subject after protocol by Medbo et al. (1988). AOD was calculated as acc O2-demand minus acc O2-uptake. All results are reported as means and standard deviation (SD). Pearson's Product Moment Correlation Analysis was used for correlation analyses. RESULTS: The subjects completed the time trial in 172 (9.9) sec. Estimated acc O2 demand was 16.0 (2.1) L, measured acc O2 uptake was 10.6 (1.2) L and AOD was therefore estimated to 5.4±1.5 L and 34 % of the O2 demand (range 18-41 %). Low to moderate correlation was found between selected physiological variables and performance time (VO2max (ml.min-1.kg-1): r=-0.50, acc VO2 (ml.kg-1): r=-0.37: O2-cost: r=-0.25, La- peak; r=-0.43). However, a strong correlation was found between AOD and performance (r=-0.71, p<0.05). DISCUSSION: The accuracy of the AOD results depend on the assumption that the economy of V2 skiing remains at values observed during submaximal loads. This assumption has been debated in general and this debate is of course also applicable to cross-country skiing. However, the size of the AOD fits with AOD in other sports in well trained athletes. Furthermore, even if AOD not gives an exact number for anaerobic contribution, the relation between subjects may be valid and therefore also the finding of a correlation to performance. CONCLUSION: In a group of elite skiers the difference in treadmill sprint performance is more related to differences in anaerobic capacity than aerobic capacity and work economy. The AOD method may be a useful tool to analyse individual performance capacity in sprint cross-country skiing.
© 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.