KAZAN (Russia) • With one eye on Rio de Janeiro, swimming's stars begin the battle tomorrow for world championship medals in Kazan to prove their form while heading into the 2016 Olympics.
As ever, the United States bring a star-studded team to the Tatarstan capital, 800km east of Moscow, with marquee names including Olympic champions Missy Franklin, Katie Ledecky, Ryan Lochte and Nathan Adrian.
Triple world-record holder Ledecky is the only American to top the 2015 world rankings in her events, with the year's best times in the 400m, 800m and 1,500m freestyle. The 18-year-old was responsible for breaking two of the six world records which fell in the Barcelona pool when the world championships were last held two years ago.
Franklin won six gold medals in Barcelona. But the 20-year-old has something to prove in Kazan after failing to win an event at a Santa Clara meet in June - her only world championships tune-up.
Likewise Lochte, who has five Olympic titles and 15 long-course world championship victories, is eager to bounce back from a 2014 he called "probably my worst year of swimming".
The 30-year-old will be swimming in his sixth world championships and is looking for a fourth straight win in the 200m individual medley. He is taking nothing for granted in the absence of three-time Olympic champion Michael Phelps and Japan's injured Kosuke Hagino .
"There's a bunch of other people out there," he said. "Just because they're not there doesn't mean it should be a shoo-in for me."
The Australian challenge will be led by two defending world champions in freestyler Cate Campbell and breaststroke specialist Christian Sprenger, who will resume his battle with South Africa's Cameron van der Burgh over 50m and 100m.
Campbell will defend her 100m freestyle title and, if all goes to plan, she will line up for the final alongside her sister Bronte.
The sisters are likely to be in action tomorrow in the women's 4x100m freestyle relay before the heats for the women's 100m freestyle on Thursday.
The Netherlands' Femke Heemskerk, along with Cate Campbell, has posted the joint fastest time for 2015 and with Olympic champion Ranomi Kromowidjojo in the mix, the Dutch swimmers will be pushing the Australian sisters all the way.
"We always have lots of tough battles from the Europeans and you can't underestimate anyone at a world championships, especially one year from an Olympic Games," said Cate Campbell. "Everyone wants to stake a claim."
Of the teenage talent to watch, 19-year-old Australian Mack Horton has posted the world's fastest 400m and 800m freestyle times.
Teenage breaststroke sensation Ruta Meilutyte, who won the 2012 Olympic 100m breaststroke as a 15-year-old, is now 18 and the Plymouth-based teenager will be looking to retain her world title she won two years ago.
The Lithuanian set both the 50m and 100m breaststroke world records at the Barcelona championships in 2013.
At the other end of the age spectrum, Grant Hackett, 35, returns after an almost seven-year hiatus and will swim in the 4x200m relay.
FINA WORLD CHAMPIONSHIPS
Synchronised swimming, team free combo final: StarHub Ch203, 10pm