Normal levels of creatinine in the blood are approximately 0.6 to 1.2 milligrams (mg) per deciliter (dL) in adult males and 0.5 to 1.1 milligrams per deciliter in adult females. Muscular young or middle-aged adults may have more creatinine in their blood than the norm for the general population.
Fiber Types and Skeletal Muscle Hypertrophy The force generated by a muscle is dependent on its size and the muscle fiber type composition. Skeletal muscle fibers are classified into two major categories; slow-twitch (Type 1) and fast-twitch fibers (Type II).
Fast-twitch fibers, also called FT or Type II fibers, have a quick contraction time, but are quick to fatigue. There are three different types of fast-twitch muscles. Type IIa muscle fiber has a moderately fast contraction time, and a relative long resistance to fatigue. Type IIx muscle fiber has a fast contraction time, and a moderate resistance to fatigue.