Development of adaptation, maintenance of normal human life in extreme environmental conditions is an urgent and a priority for all of humanity, for the recognition of the UN Commission on Sustainable Development "well-being" half of humanity in the XXI century will be directly related to the quality of development and the development of mountain areas. The purpose of the research is to study the level of physical performance, which is the most informative indicators of human adaptation to mountain conditions. The methodology of the paper presents experimental data on the effect of altitude and the duration of stay of the person on the active physical performance. It was established that during the first five days of active healthy people staying at an altitude of 2000m clearly develop beneficial effects of adaptation to muscular work. The high altitude (2300-3340) significantly increases the reaction of the cardiovascular and respiratory systems, and physical performance is reduced by 20-25%. Results of the research based on research developed gradation of physical human performance in conditions of plain and mountainous terrain.