This document provides information on muscle anatomy and physiology. It lists various muscles and muscle groups in the back, arms, legs, and core. It then discusses the two main types of muscle fibers - slow twitch and fast twitch fibers - and how they differ in terms of speed of contraction, blood supply, fatigue resistance, and use for endurance versus power activities. The document also covers how muscles work by pulling on bones via tendons, the concept of agonist and antagonist muscle pairs, and the three types of muscle contraction: concentric, eccentric, and isometric.