FILE - In this March 24, 2010, file photo, Sarah Hammer of the United States celebrates after winning the Women's Individual Pursuit at the World Track Cycling Championships at the Ballerup Arena in Copenhagen, Denmark. Three-time Olympian Sarah Hammer, one of the most decorated track cyclists in U.S. history, is retiring after a prolific career spanning more than two decades. The 34-year-old Hammer announced Monday, Sept. 18, 2017, that she's stepping away from competitive riding to focus on the training facility that she founded in Colorado Springs with her coach and husband, Andy Sparks. (AP Photo/Alastair Grant, File)