2016 Rio Olympics - Swimming - Final - Men's 50m Freestyle Final - Olympic Aquatics Stadium - Rio de Janeiro, Brazil - 12/08/2016. Anthony Ervin (USA) of USA reacts after winning the gold. REUTERS/Dominic Ebenbichler

2016 Rio Olympics - Athletics - Preliminary - Men's 400m Round 1 - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Wayde van Niekerk (RSA) of South Africa (L) competes. REUTERS/Lucy Nicholson

2016 Rio Olympics - Athletics - Preliminary - Men's 400m Round 1 - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. Kirani James (GRN) of Grenada (C) and Rusheen McDonald (JAM) of Jamaica (R) compete. REUTERS/Lucy Nicholson

2016 Rio Olympics - Athletics - Preliminary - Men's 400m Round 1 - Olympic Stadium - Rio de Janeiro, Brazil - 12/08/2016. LaShawn Merritt (USA) of USA and Hederson Estefani (BRA) of Brazil react REUTERS/David Gray

2016 Rio Olympics - Swimming - Final - Women's 200m Backstroke Final - Olympic Aquatics Stadium - Rio de Janeiro, Brazil - 12/08/2016. Maya DiRado (USA) of USA touches the wall on her way to winning the gold medal. REUTERS/Athit Perawongmetha

2016 Rio Olympics - Swimming - Semifinal - Women's 200m Backstroke Semifinals - Olympic Aquatics Stadium - Rio de Janeiro, Brazil - 11/08/2016. Maya DiRado (USA) of USA competes. REUTERS/David Gray

2016 Rio Olympics - Swimming - Final - Women's 200m Backstroke Final - Olympic Aquatics Stadium - Rio de Janeiro, Brazil - 12/08/2016. Maya DiRado (USA) of USA competes on her way to winning the gold medal as Katinka Hosszu (HUN) of Hungary swims on her way to winning the silver medal. REUTERS/Dominic Ebenbichler

2016 Rio Olympics - Swimming - Final - Women's 200m Backstroke Final - Olympic Aquatics Stadium - Rio de Janeiro, Brazil - 12/08/2016. Maya DiRado (USA) of USA reacts in front of Katinka Hosszu (HUN) of Hungary after winning the gold. REUTERS/Michael Dalder