INTRODUCTION: Because of the fact that there are benefits and risks in high altitude training (Wilber, 2003), it is reasonable to have an index for monitoring physical condition and acclimatization status in high altitude training. In this study, we have evaluated physiological meanings of resting heart rate for monitoring the physical condition and acclimatization status during 2 weeks of high altitude training in cross-country skiers. METHOD: Collegiate cross-country skiers (8 males, 6 females, 20.0 ±1.0 yrs.) lived 1 day at sea level and lived and trained for 14 days at 2,200 m. Just soon after getting up, the following items were measured in every 2 days, i.e., heart rate (HR) during orthostatic test, hemoglobin concentration (Hb), and HR and blood lactate concentration (La) during 3 minutes of submaximal cycling test at the intensity of 75% of maximal HR of each subject and 3 minutes of recovery. Erythropoietin (EPO), ferritin, red blood cell (RBC), hematocrit (Hct) were measured at sea level and day 2 and day 14. One way repeated measure of variance and correlation analyses were used for the statistical evaluations. RESULTS: Supine and standing HR significantly increased at day 2 (vs sea level) and, after that, it gradually decreased during 2 weeks of high altitude training. Supine HR significantly decreased at day 14 (vs. day 2). Salivary cortisol was significantly increased at day 2 (vs sea level) and, after that, significantly decreased at day 14 (vs day 2 and 8). EPO was significantly increased after 48 h at 2,200 m (vs. before altitude training) and significantly returned to the same level with sea level at day 14. Hb concentration significantly increased day14 (vs. con, day 2). No significant changes were found in other hematological parameters. HR during submaximal exercise significantly increased from sea level to day 2 and the increased HR at day 2 significantly decreased at day 8. Interestingly, the amount of changes (delta [d]) in supine HR from day 2 to 14 significantly correlated with [d]cortisol (from pre to 14), [d]average HR during cycling test (from day 2 to 14) and [d]La after cycling (from day 2 to 14). The amount of change in standing HR from day 2 to 14 significantly correlated with [d]EPO (from pre to 48 hours), [d]Hb (from day 2 to day 14), and [d]average HR (from day 2 to 14) during submaximal cycling test, and [d]cortisol (from day 2 to 14) (Fig. 1). CONCLUSION: It is suggested that HR at supine and standing reflected physical condition and adaptation status to 2 weeks high altitude training in cross country skiers.
© Copyright 2015 3rd International Congress on Science and Nordic Skiing - ICSNS 2015. 5-8 June 2015, Vuokatti, Finland. Veröffentlicht von University of Jyväskylä; University of Salzburg. Alle Rechte vorbehalten. / Übersetzt mit https://www.DeepL.com/Translator