Arianna Vanderpool-Wallace of Bahamas, Sarah Sjostrom of Sweden and Simone Manuel of the U.S. (from bottom) start in the women's 50m freestyle heats at the Aquatics World Championships in Kazan, Russia, August 8, 2015. REUTERS/Stefan Wermuth

Arianna Vanderpool-Wallace of Bahamas, Sarah Sjostrom of Sweden and Simone Manuel of the U.S. (from bottom) start in the women’s 50m freestyle heats at the Aquatics World Championships in Kazan, Russia, August 8, 2015. REUTERS/Stefan Wermuth

Arianna Vanderpool-Wallace of Bahamas, Sarah Sjostrom of Sweden and Simone Manuel of the U.S. (from bottom) start in the women's 50m freestyle heats at the Aquatics World Championships in Kazan, Russia, August 8, 2015. REUTERS/Stefan Wermuth

August 31, 2016 1:54 PM (UTC+8)