The use of performance-enhancing drugs in human sport is commonly referred to by the term doping, particularly by those organizations that regulate competitions. The use of performance enhancing drugs is mostly done to improve athletic performance. This is why many sports ban the use of performance enhancing drugs. Another similar use of medical technology is called blood doping, either by blood transfusion or use of the hormone erythropoietin (EPO). The use of drugs to enhance performance is considered unethical by most international sports organizations and especially the International Olympic Committee, although ethicists have argued that it is little different from the use of new materials in the construction of suits and sporting equipment, which similarly aid performance and can give competitors an unfair advantage over others. The reasons for the ban are mainly the alleged health risks of performance-enhancing drugs, the equality of opportunity for athletes, and the exemplary effect of "clean" ("doping-free") sports for the public.

Sport (or, in the United States, sports) is all forms of competitive physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Hundreds of sports exist, from those requiring only two participants, through to those with hundreds of simultaneous participants, either in teams or competing as individuals.

Sport is generally recognised as activities which are based in physical athleticism or physical dexterity, with the largest major competitions such as the Olympic Games admitting only sports meeting this definition, and other organisations such as the Council of Europe using definitions precluding activities without a physical element from classification as sports. However, a number of competitive, but non-physical, activities claim recognition as mind sports. The International Olympic Committee (through ARISF) recognises both chess and bridge as bona fide sports, and SportAccord, the international sports federation association, recognises five non-physical sports, although limits the amount of mind games which can be admitted as sports.

Lance Edward Armstrong (born Lance Edward Gunderson on September 18, 1971) is an American former professional road racing cyclist who won the Tour de France a record seven consecutive times after having survived testicular cancer. He is also the founder and chairman of the Lance Armstrong Foundation for cancer research and support. He last rode for UCI ProTeam Team RadioShack, a team he helped found.

In October 1996 he was diagnosed as having testicular cancer with a tumor that had metastasized to his brain and lungs. His cancer treatments included brain and testicular surgery and extensive chemotherapy, and his prognosis was originally poor. He went on to win the Tour de France each year from 1999 to 2005, and is the only person to win seven times having broken the previous record of five wins shared by Miguel Indurain, Bernard Hinault, Eddy Merckx, and Jacques Anquetil.

In 1999, he was named the ABC Wide World of Sports Athlete of the Year. In 2000 he won the Prince of Asturias Award in Sports. In 2002, Sports Illustrated magazine named him Sportsman of the Year. He was also named Associated Press Male Athlete of the Year for the years 2002–2005. He received ESPN's ESPY Award for Best Male Athlete in 2003, 2004, 2005, and 2006, and won the BBC Sports Personality of the Year Overseas Personality Award in 2003. Armstrong announced his retirement from racing on July 24, 2005, at the end of the 2005 Tour de France but returned to competitive cycling in January 2009 and finished third in the 2009 Tour de France. He confirmed he had retired from competitive cycling for good on February 16, 2011.

Howard L. Jacobs is an attorney in from Westlake Village, California, United States who has represented 75 or more athletes in cases, mostly about performance enhancing drugs.