The triple jumper struggled to find any form during the recent London Olympics, where he was hampered by a knee injury.
Despite speculation that he was preparing to retire, the 33-year-old has insisted that he will be competing for gold in the Russian capital next summer.
"I'm ready for the World Championships," he said. "I'm in great shape and will be back to full fitness by the time Moscow comes around. I can be back as the best triple jumper in the world."
Idowu claimed gold at the Berlin Championships back in 2009.