It has been known that ascend to high altitude is associated with the down regulation in cardiac autonomic nervous activity as compared to sea level(Hainsworth et al. 2007; Iwasaki et al. 2006). These regulations seemed to be gradually approached to near sea level with high altitude acclimatization. The purpose of this study was to investigate the availability of orthostatic test reflecting cardiac autonomic nervous activity for the evaluation of physical condition in acclimatization process of high altitude training. Methods: Cross-country skiing athletes (10 males, 6 females, 20.4±1.2) lived 1 day at sea level for collecting control data and lived and trained for 8 days at the ambient altitude approximately 1,600m above sea level. Heart rate (HR) during 10 minutes orthostatic test, HR, arterial blood oxygen saturation and blood lactate during 3 minutes step test, amylase in the saliva, urine specific gravity and subjective feeling of fatigue were measured at the every morning. Time trial of 1,500m running as an index of endurance performance was conducted at altitude in day 1, day 4 and day 8. To evaluate an influence of training loads on cardiovascular system, HR during training was recorded and calculated training impulse (TRIMP). Analysis of variance was used for the statistical evaluation. Results: No significant changes were found in HR response during orthostatic test, HR response during 3 minutes step test, the other physiological parameters and 1,500 m running performance on a subject`s mean level during 9 days. Because, there were individual differences in all variables, looking at subject`s individual data, some of subjects revealed good response to acclimatization process of high altitude training. It showed gradually approached to near sea level with high altitude acclimatization. Discussion: It is suggested that there is definite individual differences in the cardiac autonomic nervous activity response to high altitude acclimatization process. But some of subjects revealed good response to acclimatization process to high altitude training. Therefore, these responses imply that orthostatic test could be one of indexes reflecting physical condition during acclimatization process of high altitude training in endurance athletes. However, it is needed a further research to identify the individual differences of HR response.
© Copyright 2012 17th Annual Congress of the European College of Sport Science (ECSS), Bruges, 4. -7. July 2012. Veröffentlicht von Vrije Universiteit Brussel. Alle Rechte vorbehalten. / Übersetzt mit https://www.DeepL.com/Translator