Nephritis is the most common cause of blood in the urine of children and young adults but it can occur at any age. If your GP suspects nephritis he will usually refer you to a nephrologist (kidney doctor).
Muscle fiber types can be broken down into two main types: slow twitch (Type I) muscle fibers and fast twitch (Type II) muscle fibers. These fast twitch fibers can be further categorized into Type IIa and Type IIb fibers, which are also known as fast twitch oxidative and fast twitch glycolytic, respectively.
Type IIx are best known as fast-twitch muscle fibers. These are the muscle fibers primarily responsible for fast, explosive movements like sprinting. However, they lack the endurance-boosting ability of slow-twitch fibers and can only be used for short periods of time.Type IIa are what we call intermediate fibers. These are a blend between fast-and slow-twitch fibers.hese are the muscle fibers primarily responsible for fast, explosive movements like sprinting. However, they lack the endurance-boosting ability of slow-twitch fibers and can only be used for short periods of time. Type IIa are what we call intermediate fibers.