筋出力パワーの連続発揮によるＦｏｒｃｅ‐Ｖｅｌｏｃｉｔｙ特性と筋組成の関係

Abstract

The purpose of this study was to investigate the relationships between fatigue curves of muscular power and muscle fiber composition, and between the force-velocity properties and muscle fiber composition when performed powerful contractions at maximum effort in certain load. Subjects were 11 healthy adult male whose ages ranged between 22 and 61 years old. The produced muscular power measured when subjects were required to perform 100 consecutive maximum leg extensions at every 3 seconds using an improved inertia wheel ergometer with an equivalent mass of 529.3kg. Muscle fiber samples were obtained from the ventral part in m. vastus lateralis with needle biopsy technique. Fiber types were classified as fast twitch fiber (FT) and slow twitch fiber (ST), further more FT fiber was divided into FTa and FTb subgroups. Following is the results obtained in this study. 1) The abrupt reduction in muscular power around 40th to 50th consecutive maximum contraction was thought to be mainly due to the fatigue in FT fiber, especially in FTb fiber. 2) Significant correlation (r=0.613, p≤0.05) was obtained between the degree of regression line of force-velocity properties and %FT. This seemed to suggest that the higher the person's %FT was, the more the reduction in muscular power was affected by the decrease in the velocity component.