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.
I believe that muscle fiber typing is both over-rated and under-rated. People and coaches tend to fall into one of 2 groups. They either say that muscle type determines just about everything when it comes to athletic ability, or they say that muscle type makes no difference whatsoever.