At just 18 years of age, Katie Ledecky won five gold medals, broke two world records and was named female Swimmer of the Meet at the World Championships in Kazan. In a stellar performance, she became the first swimmer to achieve a clean sweep of 200m, 400m, 800m and 1,500m freestyle in a major competition and lowered the world record in the 800m by a massive 3.61 secs. She is also the current world record holder in the 400m, 800m and 1,500m freestyle. Ledecky's remarkable success has earned her Swimming World’s World Swimmer of the Year award in 2013, 2014 and 2015.