ANATOMY

Detailed explanation-1: -They contain more mitochondria and myoglobin, and are aerobic in nature compared to fast-twitch fibers. Slow-twitch fibers are also sometimes called type I or red fibers because of their blood supply.

Detailed explanation-2: -Fast twitch fibers, or type II fibers, have fewer mitochondrion and myoglobin proteins than slow twitch fibers (2). Despite the decreased amount of mitochondria, type II fibers are still able to synthesize large amounts of energy through anaerobic processes.

Detailed explanation-3: -Slow fibers have a small network of capillaries. Slow fibers contain a large number of mitochondria.

Detailed explanation-4: -Type I fibers (SO). These fibers have a rich capillary supply, numerous mitochondria and aerobic respiratory enzymes, and a high concentration of myoglobin. Myoglobin is a red pigment, similar to the hemoglobin in red blood cells, that improves the delivery of oxygen to the slow-twitch fibers.

Detailed explanation-5: -The oxidative fibers contain many more mitochondria than the glycolytic fibers, because aerobic metabolism, which uses oxygen (O2) in the metabolic pathway, occurs in the mitochondria.