McIntosh is aiming to win five gold medals in individual events at the worlds in Singapore, and the first one came Sunday in the 400-meter freestyle on the first of eight days in the pool. Only legendary American Michael Phelps has ever won five individual medals in the worlds. He also did it at the Olympics.

Huske, the Olympic 100m fly gold medalist, was among the U.S. swimmers who became sick at a pre-worlds training camp in Thailand. A majority of U.S. swimmers were affected to varying degrees by acute gastroenteritis, or a stomach bug.