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.
You canât see the process happening, but when you forgo the gym for your bed, the âslow and fast-twitch endurance muscle fibersâ (necessary for strenuous and efficient exercise) become more âeasily fatigued muscle fiber types.â. As intense as this sounds, donât freak out!