Heng refitted the wheelchairs to make it easier for the kids, until the arrival of sports wheelchairs six months later.

The ages of Heng's first batch of 26 students ranged from 7 to 17, and he taught them the ping-pong moves "bit by bit".

"I was surprised by their diligence and the progress they made. It was evident that they valued this opportunity more than those at my club and they practiced much, much harder," Heng says.

"They can do many of the shots better than me now. And that's not easy," he says, smiling.

But even more than their prowess with their bats, Heng got a bigger sense of fulfillment from the psychological changes he saw in his students as they learned to play the game.

"Many kids were introverted or felt inferior when we first met. Some of them used to crawl on the ground, looking up at the others," he says.

"Through playing ping-pong, they know they can stand up and they can achieve a lot as long as they try hard－especially after participating in so many major games and even standing on the top podium at the Paralympics. I can say every team member is quite open-minded now."

In 2013, Heng was transferred from the waterworks to a local sports school to better train his students. He also gave up his own club years ago for the same purpose.

"My friends once questioned me about how I helped a disabled kid win the gold medal, but over the past decade, it has been my students who helped me to understand there is no gain without pain, and they helped me to realize my dream," he says.

Heng called for more support for disabled athletes in training, infrastructure and employment after retirement. Unlike the centralized and regular training athletes receive for the Olympics in China, disabled athletes only receive concentrated and less systematic training before major sports events, such as the Paralympics.

"I also hope there will be more sports infrastructure and education opportunities for the disabled in daily life, so they can participate in sports and get to better know the outside world even they are not athletes," Heng says.