From not keeping up to head of the pack

Yang said physical training might be the best way for these kids — with their intelligence below average — to make something of themselves.

"I always encourage my students to participate in competitions, not because I want them to win, but because I want them to see what the world is like out there — something they may never be able to do like normal kids if not for their sports training," he said.

However, it's still uncertain whether these kids can really fully grasp the concepts of "achievement" and "finding a purpose in life".

According to Lu Guoqiang, what has been driving his brother to win more games is not big dreams but simple wishes like using his award money to buy a new car for his uncle and aunt — who helped raise him as if he was their own.

Since the Berlin trip, it seems like nothing has changed. Lu Guowei spends his days exactly like before: walking his four dogs after he gets up in the morning, helping his aunt prepare the meals for the family, lending a hand at his uncle's car wash, and playing basketball for two and a half hours after dinner. "It's just like clockwork," said Lu Guoqiang. He is not sure what his younger brother will do in the future when he is older and passed his peak physical ability.

But to Zhu, sports surely change things for kids like Lu Guowei.

"I do notice that some of them become more confident and more outgoing after they join a sports team, where they spend time training together with others," he said. "It has a hugely positive impact on their mentality."

Yang once referred to special education as the "art of slowness" as changes happen very slowly with intellectually disabled kids.

However, changes do happen.