Hungary's Katina Hosszu pulled off an impressive double Friday night, while Americans Jessica Hardy and Mike Alexandrov also earned two wins apiece at the Charlotte Grand Prix.
Michael Phelps will take another step in his comeback at a Grand Prix meet in Charlotte, North Carolina on May 16.
Denmark swimmer Mads Glasner has been reinstated as the 1,500-meter gold medalist at the 2012 world short-course championships after winning his doping case appeal.
Olympian Nathan Adrian defeated a stacked field in the 50-meter freestyle at the Austin Grand Prix on Saturday.
The United States fell behind Friday in the Duel in the Pool, putting it in position for its first loss in the event.
The records keep piling up for Katie Ledecky. She continued her banner year Saturday by shattering the American record in the 1,650-yard freestyle at the Winter National Championships.
Katie Ledecky beat Missy Franklin in a 500-yard freestyle matchup between Olympic gold medalists Thursday to highlight the first day of the Winter National Championships.
Megan Romano won the 100-yard freestyle at the Arena Grand Prix, giving the swimmer four victories in the short-course meet at the University of Minneapolis.
Megan Romano won the 50-yard freestyle and 100 backstroke at the Arena Grand Prix swimming meet Friday night.
Olympic gold medalist Conor Dwyer won the 400-yard individual medley and finished second in the 200 freestyle Thursday night at the University of Minnesota in the six-stop Arena Grand Prix Series' short-course opener.
Two-time Olympic swimming gold medalist Britta Steffen of Germany has announced her retirement.
Missy Franklin won her fourth gold medal of the world swimming championships with a strong anchor leg for the United States in the 4x200-meter freestyle relay Thursday.
Gillian Ryan won her second title in two days at the U.S. Open, winning the 400-meter freestyle Wednesday.
Missy Franklin has claimed her third gold medal of the world swimming championships with a victory in the 200-meter freestyle.
Katie Ledecky has crushed the world record in the 1,500 freestyle for her second gold medal at the world swimming championships.
Missy Franklin has claimed gold in the first of her eight events at the world championships.