This chapter explores the discipline required in competitive sports, with a focus on substance use and its effects on performance. It highlights the debate among legendary fighters like Jon Jones and Khabib Nurmagomedov as contenders for the GOAT title, along with discussions of resilience and mental strength in high-stakes matches. Additionally, the chapter delves into the complexities of injuries in elite athletes, particularly shoulder injuries, emphasizing the importance of proper recovery to maintain competitive performance.