The Bank of America Chicago Marathon today announced that U.S. Olympian Dathan Ritzenhein will return to the site of his breakthrough performance by competing in the 36 th annual event on October 13. Last fall, the Midwest native thrilled his regional fan base by finishing as the top American in Chicago and improving his marathon best by more than two minutes. His decision to return is fueled by the desire to set his sights even higher in 2013. Before culminating with the Chicago Marathon, Ritzenhein will kick off his outdoor racing season at the 34 th Bank of America Shamrock Shuffle 8K on April 7, marking his first appearance at Chicago’s popular spring road race. “After his breakthrough race last fall, it became a priority for us to have Dathan back on the start line for the 2013 Bank of America Chicago Marathon,” said Executive Race Director Carey Pinkowski. “It’s clear that he has discovered a winning formula for the marathon and Chicago fits into that plan. What I’m most excited about is now that Dathan has a comfort level with the marathon distance and with our event, I think you’re going to see a supremely confident and fit athlete mixing it up with a world-class field on October 13.” Ritzenhein is coming off a career year in 2012, highlighted by a 13 th-place finish in the Olympic 10,000-meter final as a member of his third Olympic team, and a ninth-place finish at the Bank of America Chicago Marathon in a personal best 2:07:47, making him the third-fastest American of all-time. Prior to Chicago, his previous marathon best was 2:09:55 at the 2012 U.S. Olympic Trials. His 2013 season will mirror that of 2012 by skipping a spring marathon and focusing his efforts on the outdoor track season and a bid to represent Team USA at the 2013 World Track & Field Championships in Moscow, Russia, before taking his speed to the flat and fast streets of Chicago. To jumpstart his outdoor racing campaign, Ritzenhein will headline the 2013 Bank of America Shamrock Shuffle 8K, leading the way for 40,000 runners as they usher in spring in Chicago. Growing up less than 200 miles from Chicago in Rockford, Mich., he can appreciate what the arrival of spring means to runners across the Midwest. The Shamrock Shuffle will also serve as an opportunity for the Portland, Ore.-based athlete to prepare for his fall marathon, as the course includes segments of the Chicago Marathon route, including the start and finish lines in Grant Park.