2016 Rio Olympics - Golf - Preliminary - Men's Individual Stroke Play - Olympic Golf Course - Rio de Janeiro, Brazil - 12/08/2016. Martin Kaymer (GER) of Germany chips on to the 18th green during the second round of the men's Olympic golf competition. REUTERS/Andrew Boyers

2016 Rio Olympics - Golf - Men's Individual Stroke Play - Olympic Golf Course - Rio de Janeiro, Brazil - 13/08/2016. Bubba Watson (USA) of the United States reacts after sinking a putt on the fifth hole during the third round of the men's Olympic golf compeititon. REUTERS/Andrew Boyers

2016 Rio Olympics - Athletics - Victory Ceremony - Men's 4 x 100m Relay Victory Ceremony - Olympic Stadium - Rio de Janeiro, Brazil - 20/08/2016. Usain Bolt (JAM) of Jamaica bites his gold medal. REUTERS/Dylan Martinez

Rock 'Em Sock 'Em Robots boxing games are placed on the tables inside BB Kings night club, before a night of Corporate Challenge Boxing in New York July 20, 2010. REUTERS/Lucas Jackson

Rio Olympic marathon silver medal winner Feyisa Lilesa of Ethiopia arrives at a news conference in Washington, U.S., September 13, 2016. REUTERS/Gary Cameron

Rio Olympic marathon silver medal winner Feyisa Lilesa of Ethiopia attends a news conference in Washington, U.S., September 13, 2016. REUTERS/Gary Cameron

Rio Olympic marathon silver medal winner Feyisa Lilesa of Ethiopia attends a news conference in Washington, U.S., September 13, 2016. REUTERS/Gary Cameron

Rio Olympic marathon silver medal winner Feyisa Lilesa of Ethiopia attends a news conference in Washington, U.S., September 13, 2016. REUTERS/Gary Cameron