Strength increases following training are thought to be influenced first by neural adaptions and second by large contributions from muscle growth. This is based largely on the idea that muscle growth is a slow process and that a plateau in muscle growth would substantially hinder long-term increases in strength. This Review examines the literature to determine the time course of skeletal muscle growth in the upper and lower body and to determine whether and when muscle growth plateaus. Studies were included if they had at least 3 muscle size time points, involved participants 18 years or older, and used a resistance training protocol. Muscle growth occurs sooner than had once been hypothesized, and this adaptation is specific to the muscle group. Furthermore, the available studies indicate that the muscle growth response will plateau, and additional growth is not likely to occur appreciably beyond this initial plateau. However, the current study durations are a limitation. Muscle Nerve 56: 1022-1030, 2017.