Swimmers of the United States of America encourage Michael Phelps during the men’s 4x200m freestyle relay final of swimming at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 9, 2016. The U.S. won the gold medal with 7 minutes 0.66 seconds. Phelps also earned the 21st Olympic gold medal of his staggering career. (Xinhua/Fei Maohua)