The muscle is composed of different fibre types - the slow twitch fibre (red fibres)and fast twitch fibres (white fibres). The slow twitch fibres produce tension slowly and are capable of working for hours without being fatigued as energy is produced through the oxygen dependant pathway i. e. have a higher endurance. The fast twitch fibres produced force very rapidly but have a lower endurance capacity and fatigue quickly. Long distance runners who possess good endurance capacity often have a large proportion of slow twitch fibres whereas sprinters who have to produce a large amount of energy in a very short time usually have a larger amount of fast twitch fibres in the legs. [4]
肌肉由不同种类的肌纤维构成:慢肌纤维(红纤维)和快肌纤维(白纤维)。慢肌纤维发力缓慢,适合长时间运动而不易产生疲劳感,因为能量主要依靠有氧渠道产生,这就意味着慢肌纤维具有良好的耐力水平。快肌纤维发力很快但耐力水平很低,所以很易产生疲劳感。具有良好耐力水平的长跑运动员慢肌纤维比例往往比较高。而对于短跑运动员,他们可以在很短时间内产生大量能量,腿部快肌纤维比例往往比较高。