The Olympic cross country skiing competitions in 2014 will be held in Sochi, Russia at an altitude of approximately 1500m. Although moderate, this altitude is known to reduce performance in highly trained endurance athletes. It is also known that individuals react differently during altitude exposure. The purpose of this study was to evaluate performance changes during and after three weeks of training in moderate altitude in elite skiers. METHOD: Four male and three female skiers were tested on a roller skiing treadmill using the classic technique at sea level (NORM1), after 3 and 20 days at 1500m altitude (ALT1 and ALT2), and 10 days after altitude at sea level (NORM2). The test protocol was a standardized progressive submaximal session of 4 min exercise with 1 min rest between each stage, followed by a 6-10 min progressive "all out" exercise with an increase in first speed and then grade every minute. Oxygen uptake (VO2) was measured continuously during submaximal and maximal exercise. Blood lactate concentrations were measured during the 1 min rest between submax stages and 2 min after the max test. Power at each submax and max stage were calculated from roller ski friction and body weight against gravity [1]. Each stage power was further used for calculations of power at VO2max, (WVO2max), work efficiency at submaximal loads (GE) and for the estimation of O2 cost at maximal work load (used to calculate accumulated O2 deficit (MOD)) [2]. RESULTS: At NORM1, the skiers` body mass was 71.9±10.7kg and VO2max 214±12ml/min/kg0.73. The GE varied between 17.9-19.5% during the 3-5 submaximal loads, with no difference between conditions (P>0.05). Also, blood lactate accumulation after submaximal exercise loads showed no difference between conditions (P<0.05). At ALT1, the VO2max and the WVO2max decreased 8.9% and 9.1%, respectively (P<0.05), however there were no differences between ALT1 and ALT2 or from NORM1 and NORM2 (P>0.05). In contrast, the average power output (322±87W) during the "all out" test increased 3.4±2.7% 10 days after the altitude training (P<0.05). Average MOD varied between 57-79 mlO2·kg-1 over the training period, but with no change between conditions (P>0.05). The coefficient of variation (CV%) for the changes in MOD between NORM1 and 2 was 40%. DISCUSSION: This study demonstrated that performance (VO2max, WVO2max) deteriorates by 8-9% in a group of elite skiers training at a moderate altitude corresponding to 1500m. No increase in any of the physiological parameters related to performance included in the study was seen after moderate altitude training, except for the maximal power which increased 3.4%. The response after moderate altitude training seems to be related more to anaerobic than aerobic factors. However, this was not confirmed by the MOD in this group of highly trained skiers. The large CV for change in MOD reflects the individual responses to this training. CONCLUSION: Small changes of 2-3% in performance in highly trained in elite skiers after moderate altitude training seems not to be related to any single parameter. One should not ignore individual differences in adaptation.
© Copyright 2013 Abstract Book of the 6th International Congress on Science and Skiing, December 14 - 19, 2013 St. Christoph am Arlberg - Austria. Alle Rechte vorbehalten. / Übersetzt mit https://www.DeepL.com/Translator