静力性负荷与动力性负荷时的心脏效应及其与肌纤维成份的关系

本文通过UCG分别测定11名肌纤维成份不同的青年男子划船运动员在静力性负荷与动力性负荷时相应的心功能指标并加以比较,以探讨上述两种类型负荷对心脏的不同影响;本文还讨论了心功能与肌纤维成份之间是否存在某种内在联系。

CARDIAC RESPONSE TO STATIC AND DYNAMIC EXERCISE AND RELATIONSHIP BETWEEN CARDIAC FUNCTION AND MUSCLE FIBER COMPOSITION

Cardiac functions were determined by 2-dimensional echocardiography exarcise test, in 11 young warsmenwith different skeletal muscle fiber composition during static and dynamic exercise. The static exercise wasdivided into maximal voluntary contraction (MVC) and 70% MVC. The dynamic exercise was performed ongraded cycle ergometer. The data gathered from the two exercises were compared with at the same HR. Theresults showed that stroke volume (SV), cardiac output (CO), ejection fraction (EF), and percent changesof diameter (?D) were significantly higher at dynamic exercise than those at static exercise, while the leftinnerventricular systolic pressure (IP) was significantly higher at static exercise. No significant correlationwas found between the cardiac function and skeletal muscle fiber composition among the subjects. The studyindicated that the cardiac output and contractive function were higher at dynamic exercise which was helpfulto improve cardiac reserve, while atatic exercise was not so. The result also indicated that there was nodirect relationship between muscle fiber composition and cardiac function, which should be considered whenselecting and training athletes.