Body composition and nutrition in skiing

Special requirements, such as super-maximally filled glycogen stores, short regeneration times, correct meal timing or appropriate weight specifications for ski jumping are particularly useful for endurance athletes such as cross-country skiers. A deficiency could have a fatal effect on performance and possibly a negative influence on health. While cross-country skiing is clearly one of endurance sports, ski jumping and alpine skiing are considered to be fast-strength sports or technical (acrobatic) sports. The proven advantages of carbohydrate loading (supercompensation), a nutritional technique for classic endurance loads, also apply to cross-country skiing. A drop in performance, concentration and coordination disorders as well as overheating threaten if fluid loss exceeds 2% of the total body water. Vitamin additives or sweeteners in sports drinks are inefficient. Since the higher need is actually compensated by the increased food intake with a balanced mixed diet, there is, in principle, no over-proportional need for individual vitamins in athletes. As the maximum oxygen uptake is already 15% lower from 3000 m altitude, a drop in performance is clearly noticeable there. When skiing (snowshoeing, ski touring, etc.), it should be noted that an ascent of 100 meters in altitude alone requires an additional 100–150 kcal. At moderate activity, the additional energy requirement at high altitudes compared to the sea level is estimated to be 250–290 kcal per day for men and 180–200 kcal per day for women. Top athletes in cross-country skiing can liberate 170–210 kJ/min (40– 50 kcal/min) in a dominant anaerobic manner within 2–3 minutes. The respective energy consumption is modified by numerous personal as well as external factors (for cross-country skiing, for example, the outside temperature, the friction resistance of the snow, the technique, the height profile of the route and the headwind). In cross-country skiers, the average values of body fat range between 4.8 and 12.7% in males and from 10.6 to 22.7% in females, while the average values of lean body mass (LBM) vary between 58.2 and 68.8 kg in males and from 45.6 to 48.6 kg in females. In alpine skiers, the mean values of body fat are between 9.7 and 15.8% in males and from 16.2 to 26.7% in females, and the LBM values in males range between 59.9 and 74.7 kg, in females from 42.1 to 52.8 kg. The span of body fat in male ski jumpers ranges from 8.6 to 16% with an LBM of 59.7 kg. Since 2012, a BMI of at least 21 kg/m² including suit and shoes has been a condition for ski jumpers to be able to use full-length skis (145% of body height). Otherwise, shorter skis have to be used, which reduces the wing area and is intended to reduce the jump distance as a penalty. The average values of body fat in male athletes of Nordic Combined range between 8.9 and 11.2%, and the corresponding LBM values are between 62.0 and 64.1 kg. When comparing these parameters of body composition, it must always be remembered that different methods of determining the body fat percentage have been used in corresponding studies and that possible differences do not represent a development of the skiing somatotypes over time but could also have methodological reasons.