Mexico diving coach Ma Jin is flanked by 3m springboard winner Rommel Pacheco (left) and 10m platform winner Paola Espinosa at the Pan-American Games in Toronto last year. Xinhua

As a world power in sports like table tennis, badminton and diving, China is never short of talent thanks to its rigorous State-funded cultivation system. However, the fierce competition for spots in the national team has forced some top athletes nearing or exceeding the age of 30 to migrate, particularly to Europe, for the chance to compete internationally and make a better living from their hard-earned skills.

The two oldest table tennis players at the Rio Olympics — He Zhiwen, 54, and Ni Xialian, 53 — were among the first generation of national team players who became naturalized citizens of European nations. The Chinese media dubbed them "the foreign legion".

"The Olympics is just so special that you can't turn it down when the offer comes knocking," said He, who has represented Spain since obtaining citizenship in 2002. "Moving to this country, I have been able to extend my career, so I'm grateful for the support it offered."

Born and raised in China's eastern Zhejiang province, he was part of the Chinese team that went to the 1985 World Championships, winning a bronze medal in the men's doubles. His former teammates include Cai Zhenhua, the current vice-minister of sport.

Ni, who is taking part in her fourth Olympics for Luxembourg, echoed He and said that the emotional connection she has with her adopted home has kept her competing.