The American world championship rosters will have a very different look this summer.
It's something even the veteran swimmers acknowledge will take some getting used to.
Of the 24 women who qualified for the U.S. team competing in Barcelona next month, 15 won't turn 22 until after the meet. Seven are teenagers. And of the 25 men on the roster, 12 have never been to an Olympics, 11 are 23 or younger and five of those are teens.
Change has become a traditional way of life in the swimming community in post-Olympic years. But with so many key leaders missing and so many of last year's Olympians still trying to get back in shape, the future stars of American swimming seem ready to prove themselves now.
Katie Ledecky broke one of the oldest national championship records Saturday night, finishing the 1,500-meter freestyle in 15 minutes, 47.15 seconds.
She beat 2012 Olympic teammate Chloe Sutton by 20.6 seconds and broke Janet Evans' 25-year-old long-course championship record by nearly 5seconds. It also was the fastest time in the world this year.
By winning the three longest events this week and finishing second in the 200 free, Ledecky has a chance to become the first American woman to compete in the 200, 400, 800 and 1,500 free at the world championships.
Three other Olympic gold medalists - Ryan Lochte in the men's 200 individual medley, Natalie Coughlin in the women's 50 free and Nathan Adrian in the men's 50 free - also won Saturday night.