[Features of the response of human striated muscle fibers to hypokinesia combined with physical loading].

Antiorthostatic hypokinesia for 30 days produces in human beings certain atrophic changes and decreasing metabolic level in both types of the skeletal muscle fibers, the metabolic activity being more decreased in the fibers of the II type. The physical loading of speed-power character does not prevent atrophy phenomena, nevertheless produces an increase of the metabolic activity in both types of the fibers. Changes of adaptive character, resulted from the physical loading, do not ensure a complete compensation of the negative hypoxic effect, especially in relation to contractile structures of the fiber.