Olympic double gold medalist Kosuke Kitajima put the disappointment of missing out on a gold medal at the world swimming championships behind him and said Wednesday that his personal best time in the 100-meter breaststroke final has given him a platform to build on.

Kitajima set a national record of 59.53 seconds in the 100 final but came up short in his bid to retain his world title and had to make do with a runnerup finish behind world record holder Brendan Hansen of the United States.

"It's a shame that I wasn't able to get a gold medal," Kitajima said.

"But I set a new personal best time and that will put me in good stead for next year."