Boxing, he said, appears like a violent combat on the surface, but scratch it, and you will see that it is a rational sport that needs a scientific approach, Wu said.

"Before I joined the club, I was learning it by myself. Years ago, when I went to a boxing club in Italy, they didn't even bother to take a look at me." Back then, Wu's frame was more music buff than boxer. But music and boxing share a few features, he said.

"Many think singing is dependent only on one's voice or throat. It's not the case at all. It requires your full body's attention and a singer needs to use the power or energy that is at his or her core. Similarly, boxing requires every muscle to get involved.

"Boxing is not as popular as before, because it takes too long to cultivate a champion. Sometimes, it takes over 30 years of training. Boxing is a foreign sport. It lacks the tradition in China. So this sport is facing difficulties in its development because it's too hard. Anyone from a wealthy family is not likely to make much effort to learn the art."

He said boxing is like his favorite music genre. "Vintage American-style rock-n-roll is an awesome style, but people don't recognize it."

He said more and more people like him have turned to boxing. Recreation sports are emerging as a viable, even lucrative, business segment, he said.

Agreed Cai Jialong, founder of Long FC, a game based on mixed martial arts. "In China, there are over 80 million boxing fans. With such a large crowd of potential fans, combat sports and even players may fare better in the future.

"The major demographic for this market are those aged between 18 and 30 with a relatively strong consumption power and open mind. They tend to accept the culture of combat."

Li Zhipeng, partner of BW Venture Capital, which used to invest in the country's popular workout app Keep, said more games and commercial competitions can encourage more people to take part in recreation sports with a combat element.

"Combat sports are a nascent business. People in this business are approaching it like parents would view an infant－without undue hurry about growth and future. We don't want to talk about profits right now."

But he predicted top combat players in China will be able to earn 100 million yuan annually five years from now.