The protein that is essential for muscle growth is known as myosin. Myosin is a major component of thick filaments in muscle fibers and plays a crucial role in muscle contraction. When exercising, particularly during resistance training, the muscle fibers experience small tears. The body repairs these tears by synthesizing new proteins, predominantly actin and myosin, leading to muscle growth and increased strength. Additionally, adequate intake of dietary protein is vital for providing the necessary amino acids that support the repair and building of muscle tissues after physical activity, emphasizing the importance of protein in fitness and health.