IMPROVEMENT IN ALTITUDE PERFORMANCE TEST AFTER FURTHER ACCLIMATIZATION

Introduction: The Altitude Performance Test is a measure designed to assess an individual’s degree of acclimatization in order to reduce the risk of acute mountain sickness (AMS) during high altitude activities. Objective: To investigate the hypothesis that test results will improve in a pre-acclimatized population after several days of further acclimatization. Methods: The Altitude Performance Test consists of an uphill run at high altitude. The event is timed and performed with continuous oxygen saturation (SaO2) monitoring. The individual’s time and lowest SaO2 measurement are recorded. This test was performed on the first day of arriving at Turin Hut (Mt. Blanc massif, Aosta Valley, Italy; elevation 3371 m), and after nine days at the same location. The 37 male participants of the German Army mountain guide course were all pre-acclimatized prior to arrival at Turin Hut. The sleeping altitude remained constant at 3371 m, and the daytime altitudes increased up to a maximum of 4808 m (Mt Blanc peak). The results of the first and second tests were compared using the Wilcoxon Signed Rank Test. Results: Test results improved significantly after a further nine days of acclimatization (Time: -11 sec, P ≤ 0.001; SaO2: +5%-points, P ≤ 0.001). This is remarkable because all soldiers were pre-acclimatized and, in general, showed only minor high altitude symptoms during the entire stay, even at the summit of Mt. Blanc. Conclusions: This indicates that the acclimatization process is not finished after amelioration of altitude symptoms. The demonstrated improvement in physical performance could prove very important, particularly during rescue or military missions performed at high altitude. Therefore, it is recommended that the additional time necessary for improved acclimatization be scheduled.