fast-twitch fibers

fast-twitch fi·bers

(fast-twich fī'bĕrz) Histologically distinct skeletal muscle fibers that generate energy rapidly and are active in quick, powerful actions; subclassified as types IIa and IIb.
Synonym(s): fast glycolytic (FG) fibers, fast-oxidative-glycolytic (FOG) fibers, Type II fibers.