[Composition of skeletal muscle fibers in athletes, performing work varying in duration and power]

Bioptates obtained from the musculus vastus lateralis in 1,311 sportsmen-volunteers, presenting 8 types of sports have been investigated; their special work has been performed in zones of certain power or in several zones of power. In cryostat sections after reaction of myosin ATPase, content of slow and fast muscle fibers (MF) has been counted and they have been presented in per cents. A short-time work of maximal power is more successfully performed by persons, in whose muscles less than 20% of slow MF is present. High sporting results in a more prolonged work of submaximal power get those sportsmen, in whose muscles content of slow MF is within 20-40%. A prolonged work of great and moderate power requires higher content of slow MF-60% and more. The persons, in whose muscles about equal amount of fast and slow MF is revealed, can successfully participate in those sport games and specializations, in which professional activity is connected with the work of alternative power.