[Features of the ultrastructural organization of the muscles of skaters in relation to their sport specialization and muscle fiber composition].

An electron microscopical and histochemical investigation of bioptates obtained from the external broad femoral muscle of 74 sportsmen-skaters has been performed. Structural adaptation of the muscles to speed loadings and to endurance loadings has been analysed taking into consideration contents of muscle fibers (MF) of various type. Peculiarities in ultrastructural organization of the skeletal MF in the sprinter- and stayer-skaters, who undergo training according to a special program, are described; the character of the muscle changes is also followed in the sportsmen who undergo training according to the program that does not correspond to the contents of their MF. Lesions in the latter up to the necrotic ones are mostly found in the muscles of the stayer-skaters, as well as in the sprinters trained according to the stayer program. Presence of essential destructive alterations of the muscles in the skaters, especially in those whose contents of slow muscles do not correspond to their specialization, demonstrates, evidently, the fact that the given physical loading is not adequate to the functional or potential possibilities of the organism.