INTRODUCTION: In cross-country skiing the technical equipment of an athlete constitutes a substantial part to the end performance. Ekström (1981) for instance reported a major effect of the ski span characteristics on the gliding results already 29 years ago. Each year world class athletes spend a large amount of time together with their ski technicians to find the best possible skis. The interest of this study is to find out if different Norwegian national teams select skating skis with similar characteristics. METHOD: Cross-country skating skis from the Norwegian male national teams in Cross-Country (CC), Biathlon (Bl) and Nordic Combined (NC) from four different ski brands (A = 103 skis, B = 58, C = 10 and D = 14) were tested under lab conditions. Camber characteristics were measured with a SkiSelector™ (Vendolocus Development AB, Bromma, Sweden) measurement device. Out of the span curve data, parameters like stiffness, camber height at the balance point (HBP) and the net contact length were calculated. Each ski was loaded with half and full body weight (BW) of the skier. According to the usage of the skis three categories were defined, cold, medium and warm skis. The stiffness, k (N/mm) was defined as the change of the camber height when loaded from 0.5 to 1 BW. RESULTS: The NC skiers are the lightest group with 70.3 kg in average but they use the stiftest skis (251.4 ± 53.3 N/mm), skiers from CC (78.8 kg in average) have slightly softer skis (247.2 t 86.6 N/mm) and Bl skiers (78.1 kg in average) have the softest ones (225.4 ± 65.3 N/mm). The differences in ski stiffness are highly significant between NC and Bl (p< 0.01) while no significance between the skis from the other teams was found. There is a significant difference (P £ 0.05) in the total net contact area between skis from NC and the two other teams. NC skis have an average net contact of 50.8 % of the total ski length whereas CC and Bl have 47.9 % and 45.4 %, respectively. CC skis show the highest camber height with 2.78 mm at HBP loaded with 0.5 BW whereas the skis from Bl show the largest dynamic response with a change of minus 1.84 mm when loaded from 0.5 to 1.0 BW. Skis from the NC team have the smallest dynamic response in all the categories with a change of 1.45 mm in average. DISCUSSION: There are differences in cross- country ski characteristics between the Norwegian CC, Bl and NC teams. The body weight alone is not decisive enough to explain the differences between the teams concerning ski stiffness. The ski characteristics of the teams are dominantly affected by the brand's speafic ski characteristics. The influence of competition style, length or course characteristics could not be considered in this study. Furthermore it was not distinguished between characteristics for certain disciplines, like Sprint or Long Distance skiing. REFERENCES Eckström H. Biomechanical Research applied to skiing. Thesis. Linköping University, 198
© Copyright 2012 Science and Skiing V. 5th International Congress on Science and Skiing, Dec. 14 - 19, 2010, St. Christoph am Arlberg. Julkaistu Tekijä Meyer & Meyer Sport (UK) Ltd.. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator