Rio's own golden girl Rafaela Silva who won in judo. [Photo/Agencies]

Emirati swimmer Nada Al Badwawi, who carried her country's flag at the opening ceremony, said: "We are slowly starting to change the mentality. My main goal is to break down these gender barriers and pave the way for other female swimmers."

Forty five percent of the 11,444 athletes - 5,175 - in Rio were women, slightly higher than at London 2012.

"Every national Olympic committee has now sent female athletes to the Games," an IOC spokesman said.

New sports such as weightlifting were added to the women's program in 2000, wrestling in 2004 and boxing in 2012.

The target for Tokyo in 2020, where baseball, softball and karate will be contested, is to make even more events open.

However, Yuriko Koike, governor of the Japanese host city, said it will be difficult to change mentalities in Japan.

"Women are doing fantastic performances in the world of sports, in the world of politics," said Koike.

"Unfortunately, the percentage of women parliamentarians is lower in Japan than in other major places.

"Hillary Clinton talked of a glass ceiling. I think we have got an iron ceiling.

"Along with Olympic athletes, Japan's female politicians will also take up the challenge and strive to become good role models."