Kazakhstan's Marina Volnova, left, fights United States' Claressa Shields during their middleweight 75-kg semifinal boxing match at the 2012 Summer Olympics, Wednesday, Aug. 8, 2012, in London.(AP Photo/Ivan Sekretarev)
Kazakhstan's Marina Volnova, left, fights United States' Claressa Shields during their middleweight 75-kg semifinal boxing match at the 2012 Summer Olympics, Wednesday, Aug. 8, 2012, in London.(AP Photo/Ivan Sekretarev)