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.
Types of muscle fibers. Skeletal muscle, the type that is responsible for moving our muscles when we run, is comprised of three different muscle fiber types, each with its own advantages, disadvantages, and specialty.
Skeletal muscle fibers have typically been classified as type I or slow oxidative, type IIa or fast oxidative-glycolytic, and type IIb or fast glycolytic. The mean activity of SOD, XOD and CAT in the different skeletal muscle fibers of soleus, redvastus and white vastus are given in the Table.