INTRODUCTION: Test procedures involving submaximal and maximal treadmill rotier skiing as an exercise model for estimating a physiological profile are valuable tools in evaluating training adaptations in skiers during different parts of the season (Holmberg, 2005). The standardization of equipment, especially by using the same rollerskis that have been controlled for friction coefficient (Ainegren, 2008) has to be taken into consideration. However, when going from snow to "dry" land training, changes in work efficiency for individual skiers could influence the outcome. The purpose of the study was to evaluate performance changes over the summer season by including work efficiency measurements. METHOD: Eight female elite biathlon skiers were tested before and after summer training mainly including roller skiing 2-3 hours daily. The test protocol consisted of 3.5° uphill submaximal roller skating on a treadmill for 3 x 10 min and a progressive maximal test to exhaustion within 10 min. The next day a 7.5 km race was completed at a freely chosen speed. Work efficiency (ml O2 kg-1 km-1) was calculated from the VO2 at each work load. RESULTS: The skiers' height was 171±5 cm, body mass 63.6±4.1 kg and VO2max 174±14 ml/min/kg073 with no significant change over the season (P>0.05). However, race pace over 7.5 km race increased by 8.4% (P<0.05). During submaximal skating blood lactate concentration and heart rate decreased by 27.2% and 3.9%, respectively. Accordingly, speed at a fixed blood lactate concentration of 2.8 mmol/l increased by 10.4%. Skating efficiency and cycle length increased by 4.5% and 6.2% compared at the same submaximal speeds, respectively. VO2max, which depends on both efficiency and VO2max increased by 12.4% and was the parameter with the highest correlation to performance (R2=0.64, Fig. 1). DISCUSSION: The study shows that even in a group of experienced skiers, work efficiency changes over the summer season to an identical extent as other physiological parameters. Changing from skiing on snow to roller skiing may challenge movement efficiency more than previously assumed. More importantly, the results indicate that efficiency may not be interchangeable between snow and dry land skiing. When efficiency plays a role, vVO2max may be the best parameter for describing performance. CONCLUSION: Work efficiency is an important factor for consideration when evaluating physiological profiles in skiers based on treadmill roller skating.
© Copyright 2010 Book of Abstracts. 5th International Congress on Science and Skiing, Dec. 14 - 19, 2010, St. Christoph am Arlberg. Published by University of Salzburg, Interfakultärer Fachbereich Sport- und Bewegungswissenschaft/USI. All rights reserved.