Swimming - 18th FINA World Swimming Championships - Women's Duet Free Final - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Antonio Bronic

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Final - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Antonio Bronic

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Medal Ceremony - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Gold medallists Svetlana Kolesnichenko and Svetlana Romashina of Russia, silver medallists Huang Xuechen and Sun Wenyan of China and bronze medallists Marta Fiedina and Anastasiya Savchuk of Ukraine pose. REUTERS/Antonio Bronic

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Medal Ceremony - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Silver medallists Huang Xuechen and Sun Wenyan of China stand on podium. REUTERS/Antonio Bronic

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Final - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Stefan Wermuth

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Final - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Stefan Wermuth

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Final - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Antonio Bronic

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Final - Yeomju Gymnasium, Gwangju, South Korea - July 18, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Antonio Bronic

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Preliminary - Yeomju Gymnasium, Gwangju, South Korea - July 16, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Kim Hong-Ji

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Preliminary - Yeomju Gymnasium, Gwangju, South Korea - July 16, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Kim Hong-Ji

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Preliminary - Yeomju Gymnasium, Gwangju, South Korea - July 16, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Kim Hong-Ji

Swimming - 18th FINA World Swimming Championships - Women's Duet Free Preliminary - Yeomju Gymnasium, Gwangju, South Korea - July 16, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Kim Hong-Ji

Swimming - 18th FINA World Swimming Championships - Women's Duet Technical Medal Ceremony - Yeomju Gymnasium, Gwangju, South Korea - July 14, 2019. Silver medallists Huang Xuechen and Sun Wenyan of China wave. REUTERS/Evgenia Novozhenina

Swimming - 18th FINA World Swimming Championships - Women's Duet Technical Medal Ceremony - Yeomju Gymnasium, Gwangju, South Korea - July 14, 2019. Gold medallists Svetlana Kolesnichenko and Svetlana Romashina of Russia, silver medallists Huang Xuechen and Sun Wenyan of China and bronze medallists Marta Fiedina and Anastasiya Savchuk of Ukraine pose. REUTERS/Evgenia Novozhenina

Swimming - 18th FINA World Swimming Championships - Women's Duet Technical Final - Yeomju Gymnasium, Gwangju, South Korea - July 14, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Evgenia Novozhenina

Swimming - 18th FINA World Swimming Championships - Women's Duet Technical Final - Yeomju Gymnasium, Gwangju, South Korea - July 14, 2019. Huang Xuechen and Sun Wenyan of China compete. REUTERS/Evgenia Novozhenina

China's Huang Xuechen (L) and Sun Wenyan pose with their silver medals after the synchonised swimming duet free final at the Aquatics World Championships in Kazan, Russia, July 30, 2015. REUTERS/Michael Dalder

Chinas Huang Xuechen and Sun Wenyan perform during the synchonised swimming duet free final at the Aquatics World Championships in Kazan, Russia, July 30, 2015. REUTERS/Michael Dalder

Chinas Huang Xuechen and Sun Wenyan perform during the synchonised swimming duet free final at the Aquatics World Championships in Kazan, Russia, July 30, 2015. REUTERS/Michael Dalder

Chinas Huang Xuechen and Sun Wenyan perform during the synchonised swimming duet free final at the Aquatics World Championships in Kazan, Russia, July 30, 2015. REUTERS/Michael Dalder

Russia's gold medal winner Natalia Ishchenko is flanked by China's silver medallist Huang Xuechen (L) and Spains bronze medllist Ona Carbonell (R) as they pose after the synchronised swimming solo free finals at the Aquatics World Championships in Kazan, Russia July 29, 2015. REUTERS/Michael Dalder

China's Huang Xuechen poses with her silver medal after the synchronised swimming solo free finals at the Aquatics World Championships in Kazan, Russia July 29, 2015. REUTERS/Michael Dalder

China's Huang Xuechen performs in the synchronised swimming solo free finals at the Aquatics World Championships in Kazan, Russia July 29, 2015. REUTERS/Michael Dalder TPX IMAGES OF THE DAY

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminary at the Aquatics World Championships in Kazan, Russia July 27, 2015. REUTERS/Michael Dalder

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminary at the Aquatics World Championships in Kazan, Russia July 27, 2015. REUTERS/Michael Dalder

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminary at the Aquatics World Championships in Kazan, Russia July 27, 2015. REUTERS/Michael Dalder

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminary at the Aquatics World Championships in Kazan, Russia July 27, 2015. REUTERS/Michael Dalder TPX IMAGES OF THE DAY

China's second placed Huang Xuechen (L) and Sun Wenyan, Russia's first placed Natalia Ishchenko (3R) and Svetlana Romashina and Japan's third placed Yukiko Inui (2R) and Risako Mitsui pose with medals after the synchronised swimming duet technical final at the Aquatics World Championships in Kazan, Russia, July 26, 2015. REUTERS/Michael Dalder

China's second placed Huang Xuechen and Sun Wenyan (R) pose with medals after the synchronised swimming duet technical final at the Aquatics World Championships in Kazan, Russia, July 26, 2015. REUTERS/Michael Dalder

China's Huang Xuechen and Sun Wenyan perform in the synchronised swimming duet technical final at the Aquatics World Championships in Kazan, Russia, July 26, 2015. REUTERS/Michael Dalder

China's Huang Xuechen and Sun Wenyan perform in the synchronised swimming duet technical final at the Aquatics World Championships in Kazan, Russia, July 26, 2015. REUTERS/Michael Dalder

China's Huang Xuechen and Sun Wenyan perform in the synchronised swimming duet technical final at the Aquatics World Championships in Kazan, Russia, July 26, 2015. REUTERS/Michael Dalder

Xuechen Huang and Wenyan Sun of China perform in the synchronised swimming duet technical preliminary round at the Aquatics World Championships in Kazan, Russia July 26, 2015. REUTERS/Michael Dalder

Xuechen Huang and Wenyan Sun of China perform in the synchronised swimming duet technical preliminary round at the Aquatics World Championships in Kazan, Russia July 26, 2015. REUTERS/Michael Dalder

China's Huang Xuechen and Sun Wenyan (C) pose with their gold medals after winning the women's duet synchronised swimming competition at Munhak Park Tae-hwan Aquatics Center during the 17th Asian Games in Incheon September 20, 2014. Japan's Yukiko Inui and Risako Mitsui (L) finished second and Kazakhstan's Alexandra Nemich and Yekaterina Nemich (R) finished third. REUTERS/Tim Wimborne (SOUTH KOREA - Tags: SPORT SWIMMING)

China's Huang Xuechen and Sun Wenyan pose with their gold medals after winning the women's duet synchronised swimming competition at Munhak Park Tae-hwan Aquatics Center during the 17th Asian Games in Incheon September 20, 2014. REUTERS/Tim Wimborne (SOUTH KOREA - Tags: SPORT SWIMMING)

China's Huang Xuechen and Sun Wenyan perform during their women's duet synchronised swimming competition at Munhak Park Tae-hwan Aquatics Center during the 17th Asian Games in Incheon September 20, 2014. REUTERS/Tim Wimborne (SOUTH KOREA - Tags: SPORT SWIMMING)

China's Huang Xuechen and Sun Wenyan perform during their women's duet synchronised swimming competition at Munhak Park Tae-hwan Aquatics Center during the 17th Asian Games in Incheon September 20, 2014. REUTERS/Tim Wimborne (SOUTH KOREA - Tags: SPORT SWIMMING)

China's Huang Xuechen and Sun Wenyan perform in the women's duet technical routine synchronised swimming competition at Munhak Park Tae-hwan Aquatics Center during the 17th Asian Games in Incheon September 20, 2014. REUTERS/Tim Wimborne (SOUTH KOREA - Tags: SPORT SWIMMING)

China's Huang Xuechen poses with her silver medal at the synchronised swimming solo free victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

Gold medallist Russia's Svetlana Romashina (C) poses with other medallists at the synchronised swimming solo free victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. China's Huang Xuechen (L) finished second and received the silver medal, while Spain's Ona Carbonell Ballestero finished third and received the bronze. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

Gold medallist Russia's Svetlana Romashina (C) poses with other medallists at the synchronised swimming solo free victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. China's Huang Xuechen (L) finished second and received the silver medal, while Spain's Ona Carbonell Ballestero finished third and received the bronze. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

Gold medallist Russia's Svetlana Romashina (C) poses with other medallists at the synchronised swimming solo free final victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. China's Huang Xuechen (L) finished second and received the silver medal, while Spain's Ona Carbonell Ballestero finished third and received the bronze. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

Gold medallist Russia's Svetlana Romashina (C) poses with other medallists at the synchronised swimming solo free final victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. China's Huang Xuechen (L) finished second and received the silver medal, while Spain's Ona Carbonell Ballestero finished third and received the bronze. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo free final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo free final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo free final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo free final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 24, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING TPX IMAGES OF THE DAY)

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminaries during the World Swimming Championships at the Sant Jordi arena in Barcelona July 22, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminaries during the World Swimming Championships at the Sant Jordi arena in Barcelona July 22, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo free routine preliminaries during the World Swimming Championships at the Sant Jordi arena in Barcelona July 22, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

Russia's Svetlana Romashina (C) holds her gold medal as she poses with silver medallist China's Huang Xuechen (L) and bronze medallist Spain's Ona Carbonell Ballestero at the synchronised swimming solo technical routine victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

Russia's Svetlana Romashina (C) holds her gold medal as she poses with silver medallist China's Huang Xuechen (L) and bronze medallist Spain's Ona Carbonell Ballestero at the synchronised swimming solo technical routine victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Albert Gea (SPAIN - Tags: SPORT SWIMMING)

Second placed Huang Xuechen (L) of China, winner Svetlana Romashina (C) of Russia and third placed Ona Carbonell Ballestero of Spain pose with their medals at the synchronised swimming solo technical routine victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Albert Gea (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen poses with her silver medal after finishing second in the synchronised swimming solo technical routine final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Albert Gea (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo technical routine final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Albert Gea (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen performs in the synchronised swimming solo technical routine final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen is seen underwater as she performs in the synchronised swimming solo technical routine preliminaries during the World Swimming Championships at the Sant Jordi arena in Barcelona July 20, 2013. REUTERS/Michael Dalder (SPAIN - Tags: SPORT SWIMMING)

China's Huang Xuechen and Liu Ou perform to win the bronze in the synchronised swimming duets final during the London 2012 Olympic Games at the Aquatics Centre August 7, 2012. REUTERS/Adrees Latif (BRITAIN - Tags: SPORT SWIMMING OLYMPICS)

Gold medallists Natalia Ishchenko (3rd L) and Svetlana Romashina (3rd R) of Russia pose with silver medallists Ona Carbonell Ballestero (L) and Andrea Fuentes Fache (2nd L) of Spain and bronze medallists Huang Xuechen (2nd R) and Liu Ou (R) of China during the synchronised swimming duets victory ceremony at the London 2012 Olympic Games at the Aquatics Centre August 7, 2012. REUTERS/Toby Melville (BRITAIN - Tags: SPORT SWIMMING OLYMPICS)