Zou Shiming at Radio Television Hong Kong. [Provided To China Daily]

Zou says that as a teenager he was painfully shy and could barely complete a sentence. His parents virtually gave up on him, he says, and at one stage his mother berated him, saying he had no future.

"Recently I met a few of my primary school classmates and they recalled that almost everyone in the class could beat me up."

It was boxing that eventually gave him self-confidence, he says.

"Looking back on it now, I think the unpleasant things I went through as a youngster may have greatly contributed to my turning into a more resolute person, someone who refuses to give up."

Zou says he is keen to help Mingxuan avoid going through what he went through. But he will "let him try whatever he wants to do".

"My job is just to provide guidance, and we will encourage him always to be open, just like he is now."

That willingness to be frank is apparent in the way Mingxuan talks, and may help explain his popularity with TV audiences. At the drop of a hat he will blurt out "I love you so much" to his mother and father, and, if he is feeling down, will simply say, "I'm very unhappy", Zou says.

The boy is said to be a good drummer and, to Zou's delight, a talented boxer.

"It's obviously in the genes," Zou says proudly. "I have not gone out of my way to teach him anything about boxing; he just seems to be genuinely keen on it."

Mingxuan boxes with Zou for half an hour every day, something the boy wants to do, Zou says, adding that in those circumstances he is the perfect coach for his son.

"Boxing is a very good life coach. When you bleed, you must wipe it away, and continue fighting. That's what it takes to be a man."

After winning his third Olympic medal in 2012, (before winning that gold in London he had won gold in Beijing in 2008 and bronze in Athens in 2004) he made his foray into professional boxing, at the age of 31. Many questioned the wisdom of this move, not only because of how old he was but also because China's Olympic champions are well looked after once their sporting careers are over.

However, as a youngster he had watched many of the classic title fights on black and white TV, he says, and fighting as a professional had been a dream for him.

"I would give anything for a taste of it."