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.
References in periodicals archive ?
If you are muscular, you most likely have more fast-twitch fibers responsible for short bursts of strength, speed and a dynamic jump.
This finding was particularly interesting because it is exactly opposite of what would be expected from conventional fiber type-based explanations of EMG frequency, where fast-twitch fibers would have higher frequency EMG spectra than slow-twitch fibers.
They have more capillaries and mitochondria per fiber than fast-twitch fibers (type II), yet have a slower speed of shortening and a produce less specific tension than type II fibers (Baldwin et al.
Fast-twitch fibers activate and deactivate rapidly and come in two types: "Type 2A muscle fibers" which fatigue at an intermediate rate, and "Type 2B muscle fibers" which fatigue rapidly.
Fast-twitch fibers on the other hand, have a large fiber diameter and a low mitochondrial and myoglobin content.
Although fast-twitch muscle fibers are usually larger in size than slow-twitch, slow-twitch fibers can become up to 22% larger than fast-twitch fibers with effective endurance training.
Scientists believe that the speediest sprinters may have an even higher percentage of fast-twitch fibers than the average racehorse.
Doing Pilates and regular crunches will recruit your slow-twitch and sometimes your medium-fast-twitch muscle fiber types, but you have another muscle fiber type called your fast-twitch fibers that also need to be recruited.
In both macaques and people, myosingene products appeared only in a class of muscle fibers known as fast-twitch fibers.
And that can cause your fast-twitch fibers to be used inefficiently, and even to atrophy in some cases.
7] This is in contrast to other evidence that suggests that fast-twitch fibers in the thyroarytenoid and lateral cricoarytenoid muscles are reinnervated more rapidly and to a greater degree than slow-twitch fibers.