Australia's Kylie Palmer, right, and United States' Allison Schmitt compete in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, July 30, 2012. AP

United States' Allison Schmitt, top, Australia's Kylie Palmer, center, and Agnes Mutina of Hungary compete in a women's 200-meter swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

United States' Allison Schmitt, top, and Sweden's Sara Sjostrom compete in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

China's Wang Shijia competes in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

United States' Allison Schmitt competes in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

Britain's Caitlin McClatchey reacts after competing in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

Italy's Federica Pellegrini, left, and United States' Missy Franklin react after competing in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

Italy's Federica Pellegrini looks at her time after competing in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

Denmark's Pernille Blume looks on after competing in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP

Italy's Federica Pellegrini smiles after competing in a women's 200-meter freestyle swimming heat at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London. AP