RIO DE JANEIRO, BRAZIL - AUGUST 07:  Michael Phelps of the United States celebrates after winning the gold medal in the Men's 4 x 100m Freestyle Relay on Day 2 of the Rio 2016 Olympic Games at the Olympic Aquatics Stadium on August 7, 2016 in Rio de Janeiro, Brazil. The gold medal is the 19th of Phelps career.  (Photo by Clive Rose/Getty Images)