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Øyvind Skattebo, Thomas Losnegard, and Hans Kristian Stadheim

specialize, mainly competing in 1 or a few race formats to optimize physiological performance and rank; elite sprint-specialized skiers are heavier and have a larger anaerobic capacity but display lower body mass normalized VO 2 max compared with distance XC skiers, most likely due to a combination of

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John G. Seifert, Ronald W. Kipp, Markus Amann, and Oladele Gazal

This study examined energy and fluid supplementation on indices of muscle damage during alpine skiing. Skiers were assigned to a carbohydrate-protein (CP), placebo (PL), or no fluid (NF) group. CP and PL ingested 1.62 L during and after skiing. Myoglobin did not change from pre-skiing (PS) to 2 h post-skiing (2PS) for CP (24.8 ± 1.4 and 25.6 ± 1.6 ng/mL), but rose significantly from 26.4 ± 1.3 to 40.0 ± 2.8 ng/mL for PL and from 29.0 ± 1.3 to 82.9 ± 3.6 ng/mL for NF. Creatine kinase was maintained from PRE to 2 PS for CP, but increased significantly from 117 ± 7.2 to 174 ± 43.4 U/L for PL and from 126 ± 23.2 to 243 ± 34.3 U/L for NF. This study demonstrates that ingestion of a CP beverage minimized muscle damage indices during skiing compared to PL and NF and that ingesting fluids may also minimize muscle damage compared to a NF condition.

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Marta Stepien-Slodkowska, Krzysztof Ficek, Pawel Zietek, Mariusz Kaczmarczyk, Wioletta Lubkowska, Miroslawa Szark-Eckardt, and Pawel Cieszczyk

Context:

The most commonly injured body part for skiing has been found to be the knee. The rupture of the anterior cruciate ligament (ACL) was the most frequent diagnosis. ACL ruptures are determined by several extrinsic and intrinsic risk factors including those that are hormonal, neuromuscular, anatomical, or genetic.

Objectives:

To examine the association of both COL1A1 rs1800012 (+1245G/T) and COL1A1 rs1107946 (–1997G/T) polymorphisms, individually and as haplotypes, with ACL ruptures in recreational Polish skiers.

Design:

Genomic DNA was extracted from buccal cells donated by the subjects, and genotyping was carried out using real-time polymerase chain reaction.

Settings:

University laboratory.

Participants:

138 male recreational skiers with surgically diagnosed primary ruptures and 183 apparently healthy male recreational skiers not differing markedly in age or level of exposure to ACL injury.

Main Outcome Measures:

COL1A1 rs1800012 and COL1A1 rs1107946 polymorphisms.

Results:

There were significant differences in genotype distribution of the COL1A1 rs1800012 polymorphism between the ACL rupture group and the control group. The GG homozygotes were underrepresented in the ACL rupture group compared with the control group. There were no significant differences in genotype distribution or allele frequency of COL1A1 rs1107946 polymorphisms between the ACL rupture group and the control group. The G-G (COL1A1 rs1800012G and COL1A1 rs1107946G) haplotype was the most common. There were no significant differences in haplotype distribution between the ACL-rupture and control groups.

Conclusion:

The study showed that GG homozygotes were underrepresented in the ACL-rupture group compared with the control group, which suggests an association with reduced risk of ACL injury.

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Christopher M. McLeod, Haozhou Pu, and Joshua I. Newman

During 2008, Beijing residents enjoyed 274 days of air equal to, or better than, the national Air Quality Standards ( UNEP, 2009 ). These days, also known as “blue sky days,” were up from 177 in 2000, 203 in 2002, 229 in 2004, and 241 in 2006, meaning an increase of 33 more days during 2008 where

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Erik Spring, Sauli Savolainen, Jari Erkkilä, Tuomo Hämäläinen, and Pekka Pihkala

The drag area CDA of three male cross-country skiers as a function of their velocity was determined from their retardation when they were gliding on roller-skis over a horizontal smooth asphalt surface in a subway. The results show that CDA is a slightly decreasing function of the skier’s velocity in the velocity range 5–11 m/s. The drag area of a skier was found to be 0.27 ± 0.03 m2 in a semi-squatting posture and 0.65 ± 0.05 m2 in an upright posture for an average size skier (weight 80 kg, height 1.75 m). The difference in the drag area between a normal outdoor suit and a tight-fitting ski suit was found to be as much as 30%. A skier keeping pace with a skier ahead will gain a reduction in drag of about 25 %. The leading skier in this study was found to have his drag reduced by approximately 3 % compared to what it would be if there were no skier pacing up with him. The skier behind hinders the skier ahead from generating to a full extent the vortexes behind himself or herself. These reductions are of course strongly dependent on the distance between the skiers.

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Erik Trøen, Bjarne Rud, Øyvind Karlsson, Camilla Høivik Carlsen, Matthias Gilgien, Gøran Paulsen, Ola Kristoffer Tosterud, and Thomas Losnegard

Over the past few decades, cross-country skiing has evolved, with the introduction of new competition forms such as sprint and mass start and changes in the preparation of skis, course profiles, skiers’ equipment, and techniques. 1 , 2 Consequently, with higher average speeds in today

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Amelia Carr, Kerry McGawley, Andrew Govus, Erik P. Andersson, Oliver M. Shannon, Stig Mattsson, and Anna Melin

cross-country skiers’ carbohydrate intakes have been reported to range from 6.0 to 9.6 g·kg −1 ·day −1 , depending on the energy expenditure at different periods within a training year ( Fogelholm et al., 1992 ). However, carbohydrate intakes in cross-country skiers have yet to be determined before

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Wolfgang Schobersberger, Michael Mairhofer, Simon Haslinger, Arnold Koller, Christian Raschner, Sibylle Puntscher, and Cornelia Blank

according to the rankings of the International Ski Federation (Fédération Internationale de Ski; FIS) in elite Austrian skiers from 1997 to 2000. Correlations between VO 2 max (corrected for body weight; VO 2 max, mL/kg/min) and maximal power output ( P max , corrected for body weight; W max /kg) with FIS

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Evgeny B. Myakinchenko, Andrey S. Kriuchkov, Nikita V. Adodin, and Victor Feofilaktov

effects. Numerous investigations of the training process for cross-country skiers (XC) have been conducted in recent years. Analysis of main TrVs and characteristics, training-intensity distribution under time-in-zone (TIZ) and session-goal approaches, pretapering and tapering phases, and tendencies in

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Kerry McGawley, Matt Spencer, Anna Olofsson, and Erik P. Andersson

minimize the inevitable development of fatigue. 11 The relative demands on the aerobic and anaerobic energy pathways have been reported as ∼ 35% to 45% and 55% to 65%, respectively, during a single slalom/giant slalom run. 12 , 13 Additional physical challenges require alpine skiers to adopt streamlined