Michael Phelps, the most decorated Olympic athlete in history, will take on a new opponent in the water: a Great White shark. As part of its annual Shark Week, Discovery Channel announced that the 23-time gold medal winner will swim in competition against one of nature's deadliest, and quickest, marine predators. In case you were wondering, Great Whites clock in at an impressive 25 mph in open water while Phelps, one of the most elite athletes on the planet, averages between 5.25-6 mph.