How Katie Ledecky is dominating distance swimming

Swimmer Katie Ledecky has been blowing by the competition and setting records at the world championships in Russia. She’s currently on pace to sweep the 200, 400, 800 and 1,500 meter freestyles at a single world championship. To find out more about Ledecky’s incredible feats, Hari Sreenivasan speaks to sports commentator and former Olympic gold medalist Summer Sanders.