The use of performance-enhancing drugs in competitive sports, also known as doping, goes back to ancient times when athletes would consume special diets and treatments believed to enhance their performance. Most international sports organizations consider doping through banned substances unethical and prohibit it. Athletes found to have used banned substances may face penalties from both their sport's governing body and local laws, though anti-doping policies and laws can sometimes conflict between the two. Doping control protocols require athletes to provide urine samples to test for banned substances, with the option for the athlete to request analysis of a second sample if the first tests positive.