Katie Ledecky kicks off Olympic year with 52-second win in 1500m freestyle

• Ledecky wins 1500 free at Pro Swim series meet in Knoxville
• American now holds 17 fastest times in history at distance

Katie Ledecky launched the Olympic year with another dominant victory in the women's 1500m freestyle on Wednesday at the Pro Swim series meeting in Knoxville, Tennessee.

Ledecky's time of 15min 38.81sec is the 17th-fastest in history. She owns all of the 16 faster times with the second-fastest performer ever, Denmark's Lotte Friis, now holding the 18th-fastest time ever of 15:38.88.