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Muscle Fiber Composition

Meaning

Muscle fiber composition refers to the relative proportions of different contractile fiber types within a specific skeletal muscle. These primary types are broadly categorized as Type I, known as slow-twitch oxidative fibers, and Type II, or fast-twitch fibers, which are further subdivided into Type IIa (fast-oxidative glycolytic) and Type IIx (fast-glycolytic). This inherent distribution dictates the muscle’s functional capabilities and metabolic profile.