 Complete the following phrase:  In athletics, Vietnam was represented by Nguyễn Thành Ngưng and Nguyễn Thị Huyền. Ngưng was chosen based on his record-breaking result at the Asian Race Walking Championships in March 2016, while Huyềns winning performance in June 2015 at the Southeast Asian Games met the criteria for both the 2015 World Championships and 2016 Summer Olympics. Ngưng and Huyền both made their Olympic debuts and were the only qualified athletes from Southeast Asia by the International Association of Athletics Federations. Ngưng participated on 12 August in the 