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.
When lifting weights, 2B fibers help you lift heavy with great power. 2B, fast-twitch fibers drive explosive power when doing 1RM or sets of low, heavy repetitions. Type 1, slow-twitch fibers are more suited to muscle endurance training, for example, sets of 20-30 repetitions.