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.
With the Weider Iso-Tension Training Principle, work your muscles without weights. Written by FLEX Staff. Muscles are comprised of fibers composed of myofibrils that make contact with each other during muscle contractions. The strength of the contraction depends on the number of fibers and the tension within each fiber.