China's Ding Ning returns the ball against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

China's Ding Ning returns the ball against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

China's Li Xiaoxia serves the ball against her compatriot Ding Ning during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

China's Ding Ning serves the ball against her compatriot Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

China's Ding Ning reacts during the women's singles gold medal match of table tennis against her compatriot Li Xiaoxia at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Lin Yiguang)

China's Ding Ning reacts during the women's singles gold medal match of table tennis against her compatriot Li Xiaoxia at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Lin Yiguang)

China's Ding Ning returns the ball against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Shen Bohan)

China's Ding Ning serves the ball against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Shen Bohan)

China's Ding Ning returns the ball against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Shen Bohan)

Gold medalist China's Ding Ning attends the awarding ceremony for the women's singles final of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

Silver medalist China's Li Xiaoxia attends the awarding ceremony for the women's singles final of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

Gold medalist China's Ding Ning (C), silver medalist China's Li Xiaoxia (L), bronze medalist Kim Song I of the Democratic People's Republic of Korea (DPRK) attend the awarding ceremony for the women's singles final of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. (Xinhua/Shen Bohan)

China's Ding Ning reacts after the women's singles gold medal match of table tennis against her compatriot Li Xiaoxia at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Lin Yiguang)

China's Ding Ning (L) shakes hands with her compatriot Li Xiaoxia after the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Lin Yiguang)

China's Ding Ning serves against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Lin Yiguang)

China's Ding Ning returns the ball against her compatriot Li Xiaoxia during the women's singles gold medal match of table tennis at the 2016 Rio Olympic Games in Rio de Janeiro, Brazil, on Aug. 10, 2016. Ding Ning won the gold medal. (Xinhua/Lin Yiguang)