Relationship between muscle fascicle length and sports performance

肌纤维缩短速度是决定短跑成绩的合理指标。缩短的速度由生物化学和建筑性质决定。本项目的目的是在活体内研究腿部肌肉的结构特征与短跑成绩之间的关系。优秀短跑运动员所选择的运动肌束长于优秀长跑运动员。男、女100m短跑运动员的短跑成绩与肌束长度有关。短跑运动员腿部肌肉中观察到的较大的束束长度似乎有利于缩短速度，以获得更快的跑步速度。然而，运动员的肌束长度存在较大的个体间差异，但造成这种现象的原因尚不清楚。肌束长度可能主要由遗传和/或环境因素决定。对9对同卵双生子进行了研究，发现遗传倾向是决定肌束长度的主要因素。然而，MG肌束长度数据增加了肌束长度可能进一步受到外部环境因素(如体育训练)影响的可能性。与对照组相比，肌肉极度肥大的相扑运动员的肌束长度更长。肌束相对长度与肌肉大小相关。此外，青少年足球运动员肌肉大小的差异(优势腿减去非优势腿)与肌束长度的差异有关。因此，运动训练可能会进一步影响肌束的长度。

Muscle fiber shortening velocity is a reasonable parameter for the determination of sprint performance. Velocity of shortening is determined by biochemical and architectural properties. The purpose of this project was to examine the relationship between architectural characteristics of leg muscles and sprint running performance in vivo. Fascicle length of the selected locomotor muscles is greater in elite sprinters than that of the elite distance runners. Sprint running performance is related to muscle fascicle length in male and female 100-m sprint specialists. Greater fascicle length observed in leg muscle of sprinters would appear to favor shortening velocity as required for greater running speed. However, a large inter-individual variation is seen in muscle fascicle length in the athletes, but the reasons for this phenomenon are unclear. Muscle fascicle length might be determined primarily by genetic and/or environmental factors.Nine monozygous twin pairs were studied, and it appears that genetic predisposition is the predominant factor for determination of muscle fascicle length. However, MG muscle fascicle length data raise the possibility that fascicle length may be further influenced by external environmental factors such as physical training. The sumo wrestlers with extreme muscle enlargement have greater fascicle length compared with control subjects. Relative fascicle length correlate with muscle size. Also the difference (dominant leg minus non-dominant leg) in muscle size is correlated with the difference in muscle fascicle length in the junior soccer players. Therefore, it appears possible that fascicle length may be further influenced by physical training.