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).
Muscle Fibers Do Different Things. Your skeletal musclesâthe ones you check out in the mirrorâhave two main types of fibers. Type I fibers, also called slow-twitch, are used mainly for endurance activities. Type II, or fast-twitch, begin to work when a task utilizes more than 25 percent of your maximum strength.