Name: Dathan Ritzenhein

Country: United States

Stats: Ritzenhein finished ninth at the Bank of America Chicago Marathon last year with a personal best of 2:07:47, making him the third-fastest American of all-time. He finished 13th in the Olympic 10,000m final as a member of his third Olympic team.

Details: The Michigan native has won accolades for his running performance since high school. He rose through the college ranks and finished 11th in his marathon debut in New York in 2006 with a time of 2:14:01. He is no stranger to Chicago and was the first American to cross the finish line at last year's marathon.