Ledecky fights fatigue to stay on course for four golds

Katie Ledecky from the U.S. swims in the women's 200m freestyle final at the Aquatics World Championships in Kazan, Russia August 4, 2015. REUTERS/Michael Dalder

KAZAN, Russia (Reuters) - For the first time at this year's world championships, Katie Ledecky, the world’s most dominant swimmer, experienced a fleeting moment of vulnerability after three days of hard racing.

It came on Tuesday at the Kazan Arena, as the 18-year-old American attempted a double that no other rival has in their schedule -- the 1500 metres freestyle final followed a little under 30 minutes later by the 200m freestyle.