The last time PepsiCo overhauled its Gatorade strategy, Indra Nooyi was chairman and CEO. Back in 2009, amid the Great Recession, Nooyi attributed a slump in Gatorade sales to the fact that couch potato consumers, who “didn’t really have a right to exist in the Gatorade world,” had turned to other beverages, including tap water. The brand’s solution at the time was...