Hormones play a crucial role in muscle growth and metabolism. Key hormones, such as testosterone, human growth hormone (HGH), and insulin, significantly influence muscle repair, recovery, and the process of building new muscle tissues. These hormones interact to regulate energy utilization and protein synthesis. An imbalance in hormones can impede muscle growth or contribute to fat accumulation. Understanding these hormonal effects can guide individuals in maximizing their training results and optimizing overall metabolic health.