Sydney Olympic gold medalist Naoko Takahashi on Monday left Japan for Colorado, where she will officially kick off her training in a bid to win back-to-back Olympic titles next summer in Athens.

Takahashi, who joined the Skynet Asia Airways team earlier this month, is scheduled to run in the Tokyo International Women's Marathon in November after taking part in high-altitude road workouts in her training base in Boulder, Colo.

Last year, Takahashi withdrew from the Tokyo International Women's Marathon because of a stress fracture in her left rib. The fracture was discovered at a hospital in Japan shortly after she returned from Colorado.