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).
Type I Fibers. Type I fibers are âslow twitchâ fibers. They use oxygen to fire, and they take longer to get going, but they can go for a longer period of time without getting tired. The force per contraction on these muscle fibers is spread out over time. People who have trained for marathons and enjoy running long distances (not me) will have a higher percentage of Type I fibers (that are more efficient) than a sprinter or a couch potato. Type IIb Fibers. Type IIb fibers are âfast twitchâ fibers.