Performance-enhancing substances are drugs or supplements that athletes use to improve their physical abilities, such as strength, speed, or endurance. These substances can include anabolic steroids, stimulants, and hormones like erythropoietin (EPO). While some athletes believe these substances can give them a competitive edge, they often come with significant health risks and ethical concerns. The use of performance-enhancing substances is banned in most professional sports, including the Olympics and Major League Baseball. Organizations like the World Anti-Doping Agency (WADA) enforce strict regulations to ensure fair competition and protect athletes' health. Testing for these substances is common to deter their use.