Muscle growth does not increase the number of myoblasts, but only the cell size and protein capacity, a process related to satellite cells in skeletal muscle.
Muscle consists of myofibers, and the number of myofibers will not change from embryonic development to a few months after birth, so human muscle can not rely on the number of myofibers to grow. Therefore, muscle growth can only be achieved through the thickening of muscle fibers to achieve physiological hypertrophy.
The hypertrophy of muscle fibers requires load training, i.e., high weight, high intensity training to stimulate the muscles, the satellite cells in the skeletal muscle are activated after the tearing of muscle fibers, and proliferation and differentiation, the formation of new muscle fibers to repair the damaged area. At the same time, the body through the timely supplementation of large amounts of protein to repair the torn muscle fibers, when the broken muscle fibers completely healed after the muscle will become thicker.