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.
Thus the classification for muscle fibers also applies for motor units. Some of the different characteristics of muscle fiber (and motor unit) types are listed in the table. These are grouped in colors according to four basic features about muscle fibers.hus the classification for muscle fibers also applies for motor units. Some of the different characteristics of muscle fiber (and motor unit) types are listed in the table. These are grouped in colors according to four basic features about muscle fibers.