Applied physiology of cross-country skiing.

Cross-country ski racing has evolved rapidly in recent years. Of particular interest has been the development and proliferation of the faster freestyle or skating techniques. In spite of changes in technique and equipment, the fact that elite cross-country ski racers have some of the highest aerobic power values reported for endurance athletes has not changed. Successful ski racers have higher percentages of slow twitch muscle fibres and higher anaerobic thresholds, but lower anaerobic power scores than Alpine skiers. Cross-country skiers are also lean, as are distance runners. The absolute bodyweight of the ski racer, however, is much more variable than that of distance runners. Since light skiers will have an advantage on steep uphill courses and heavier skiers will be favoured by level, downhill, and less steep uphill courses, the variability of courses available in international competition explains why successful skiers are so variable with respect to bodyweight. The physiological characteristics of the elite skier are a result of both genetics and adaptation to rigorous multiyear, year-round training programmes. Identification of systematic procedures for specifically challenging the physiological parameters which are requisite for ski racing are being examined. Investigation of ventilatory and lactate thresholds as well as heart rate as parameters for quantifying training intensity is of particular interest at this time.