摘抄：Pete McCall
運動科學和健康促進碩士學位「華盛頓郵報」、「紐約時報」、「洛杉磯時報」、「亞軍世界與自我」中擔任專家。
翻譯：張凌翔Michael zhang
Here are things to know about fast-twitch, or type II, muscle fibers:
1.Fast-twitch fibers can be further classified into (1) fast-twitch IIa - fast oxidative glycolytic, because they use oxygen to help convert glycogen to ATP, and (2) fast-twitch type IIb - fast glycolytic, which rely on ATP stored in the muscle cell to generate energy.
2.Fast-twitch fibers have a high threshold and will be recruited or activated only when the force demands are greater than the slow-twitch fibers can meet.
3.The larger fast-twitch fibers take a shorter time to reach peak force and can generate higher amounts of force than slow-twitch fibers.
4.Fast-twitch fibers can generate more force, but are quicker to fatigue when compared to slow-twitch fibers.
5.The phasic muscles responsible for generating movement in the body contain a higher density of fast-twitch fibers.
6.Strength and power training can increase the number of fast-twitch muscle fibers recruited for a specific movement.
7.Fast-twitch fibers are responsible for the size and definition of a particular muscle.
8.Fast-twitch fibers are called 「white fibers」 because do not contain much blood, which gives them a lighter appearance than slow-twitch fibers.
As you can see, the characteristics of fast-twitch fibers are more suited for explosive, strength-and power-based sports like football. Therefore, when an announcer talks about how a training program benefits a specific type of muscle fiber, they are being accurate with the science.
以下是快肌纖維或II型肌纖維的相關信息：
1、 快肌纖維可以進一步分為（1）快速收縮IIa-快速氧化糖酵解，因為它們使用氧氣幫助將糖原轉化為ATP，以及（2）快速收縮型IIb-快速糖酵解，其依賴於ATP儲存在肌肉細胞中產生能量。
2.、快速抽搐纖維具有高閾值，並且僅當力需求大於慢肌纖維可以滿足時才會被募集或激活。
3、 較大的快速收縮肌纖維需要較短的時間才能達到峰值，並且比慢速收縮肌纖維產生更大的力。
4、 快速肌纖維可以產生更大的力，但與慢速肌纖維相比，它們更容易疲勞。
5、負責在體內產生運動的相位肌肉含有較高密度的快肌纖維。
6、高強度和力量訓練可以增加為特定運動招募的快肌纖維的數量。
7、快肌纖維負責特定肌肉的大小和定義。
8、快肌纖維被稱為「白色纖維」，因為它不含大量血液，這使得它們比慢肌纖維更輕盈。
正如您所看到的，快速抽搐纖維的特性更適合像足球這樣的爆炸性，力量和力量運動。因此，當播音員談論培訓計劃如何使特定類型的肌纖維受益時，他們對科學的準確性是準確的。
Techniques for engaging fast-twitch fibers:
Resistance training with heavy weight stimulates muscle motor units to activate more muscle fibers. The heavier the weight, the greater the number of fast-twitch fibers will be recruited.
Performing explosive, power-based movements, whether it is with a barbell, kettlebell, medicine ball or simply your own body weight, will recruit greater levels of fast-twitch fibers.
Fast-twitch fibers will fatigue quickly, so focus on using heavy weight or explosive movements for only a limited number of repetitions (e.g., two to six) for maximum effectiveness.
Because they deplete energy quickly, fast-twitch fibers require longer rest periods to allow motor units to recover and to replace spent ATP. Therefore, allow at least 60 to 90 seconds of rest after each explosive or strength exercise.
快速纖維的技術：
1、重量級的阻力訓練刺激肌肉運動單位激活更多的肌肉纖維。重量越重，快速抽搐纖維的數量就越多。
2、無論是槓鈴，壺鈴，藥球還是僅僅是你自己的體重，進行爆發力的，基於動力的動作都會募集出更高水平的快肌纖維。
3、快速抽搐纖維會很快疲勞，所以專注於使用重量或爆發力運動只能進行有限次數的重複（例如，2到6次）以獲得最大效果。
4、由於它們能夠快速消耗能量，因此快速收縮肌纖維需要更長的休息時間才能恢復ATP。因此，每次爆發力訓練或力量訓練後，至少要休息60至90秒。
了解身體的生理學如何適應運動可以幫助您開發更有效的鍛鍊計劃，以滿足您的特定需求。遺傳學決定了你擁有的每種肌纖維類型的數量; 然而，確定您是快速還是慢速抽搐需要進行有創肌肉活檢。因此，如果您發現您傾向於享受更多基於耐力的活動並且相對容易，那麼您可能會有更多的慢肌纖維。相反，如果你真的不喜歡長跑，但喜歡玩依賴短時爆發性運動的運動，或者如果你喜歡體重訓練，因為它相對容易，你可能是快速收縮纖維佔主導地位。
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