A woman attends a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. Women have boxed as long as the sport has existed but for years they were relegated out of national and international competitions in many countries around the world. Female boxers entered the ring in an exhibition match at the 1904 Olympic Games, but it was more than a century later when they were given the green light to make their Olympic debut in London in 2012. In China, although there is a long history of lightweight Chinese fighters, the sport is not very popular among women. However in 2010, Gong Jin, a woman who has trained since she was 12 years old, founded Princess Women's Boxing Club, the first “only for women” boxing club in China. Today more than 100 students between the ages of 18 and 40 train at the small studio in downtown Shanghai. (Photo by Carlos Barria/Reuters)

A pair of boxing gloves are seen by a window at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Vin Huang arrives at Princess Women's Boxing Club in Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)

Vin Huang prepares for her boxing class at Princess Women's Boxing Club in Shanghai December 6, 2014. (Photo by Carlos Barria/Reuters)

Women attend a boxing class at Princess Women's Boxing Club in Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)

Women attend a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Vin Huang prepares for her boxing class at Princess Women's Boxing Club in Shanghai December 6, 2014. (Photo by Carlos Barria/Reuters)

A woman dodges a punch during a boxing class at Princess Women's Boxing Club in Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)

A woman attends a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Women attend a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

A woman attends a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

A woman punches during a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Women attend a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Women attend a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Vin Huang warms up before a boxing class at Princess Women's Boxing Club in Shanghai December 6, 2014. (Photo by Carlos Barria/Reuters)

A woman prepares for a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

A woman laughs during a boxing class at Princess Women's Boxing Club in Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)

A woman takes a break during a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Women hold their hands together as they finish a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. (Photo by Carlos Barria/Reuters)

Vin Huang walks into a subway station after a boxing class at Princess Women's Boxing Club in Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)

Vin Huang looks at her mobile phone as she travel on the subway on the way to her boxing training class in Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)

Gong Jin (C), founder of Princess Women's Boxing Club, teaches a boxing class at her boxing club in downtown Shanghai December 8, 2014. (Photo by Carlos Barria/Reuters)