Each individual muscle fiber is a thin, elongated cylinder that generally extends the length of the muscle. The cell membrane surrounding the muscle fiber cell is called the sarcolemma. Located above the sarcolemma and below the basal lamina are a group of muscle precursor cells called satellite cells. Satellite cells are undifferentiated cells that play a key role in muscle growth and repair (81). For ex ample, satellite cells can contribute to muscle growth during strength training by dividing and contributing nuclei to existing muscle fibers. Increasing the number of nuclei within muscle fibers enhances the fibers' ability to synthesize proteins and, therefore, assists in muscle growth (81)