2016 Rio Olympics - Athletics - Final - Men's 800m Final - Olympic Stadium - Rio de Janeiro, Brazil - 15/08/2016. David Lekuta Rudisha (KEN) of Kenya celebrates after winning the race REUTERS/Dylan Martinez

2016 Rio Olympics - Tennis - Preliminary - Women's Singles Third Round - Olympic Tennis Centre - Rio de Janeiro, Brazil - 09/08/2016. Serena Williams (USA) of USA reacts during her match against Elina Svitolina (UKR) of Ukraine. REUTERS/Kevin Lamarque

International team members Jason Day (R) and Adam Scott of Australia stand on the first green during the four ball matches of the 2015 Presidents Cup golf tournament in Incheon, South Korea, October 9, 2015. REUTERS/Kim Hong-Ji

2016 Rio Olympics - Athletics - Final - Women's 3000m Steeplechase Final - Olympic Stadium - Rio de Janeiro, Brazil - 15/08/2016. Ruth Jebet (BRN) of Bahrain celebrates after winning the race REUTERS/Lucy Nicholson

2016 Rio Olympics - Athletics - Final - Men's 100m Final - Olympic Stadium - Rio de Janeiro, Brazil 14/08/2016. Usain Bolt (JAM) of Jamaica celebrates after winning the race REUTERS/David Gray

2016 Rio Olympics - Athletics - Final - Men's 100m Final - Olympic Stadium - Rio de Janeiro, Brazil 14/08/2016. Usain Bolt (JAM) of Jamaica celebrates after winning the race REUTERS/David Gray

2016 Rio Olympics - Athletics - Final - Men's 100m Final - Olympic Stadium - Rio de Janeiro, Brazil 14/08/2016. Justin Gatlin (USA) of USA reacts after the race REUTERS/Dylan Martinez

2016 Rio Olympics - Athletics - Final - Men's 100m Final - Olympic Stadium - Rio de Janeiro, Brazil 14/08/2016. Usain Bolt (JAM) of Jamaica celebrates as he crosses the finish line to win the race in this photofinish picture. OMEGA/Handout via REUTERS