Li said that the runners are kind and are always grateful for volunteers' help.

"They are considerate and often worried about if the volunteers would be too exhausted, sometimes they even crack jokes to make volunteers laugh", he said.

"They bring positive energy to our lives and their optimistic attitude toward life is inspirational", he added.

The spirit of partnership does not end when they cross the finish line. Li and other volunteers also take runners for medical checkups and buy them new gear. "I am proud of what I've done for them." Li said.

In order to better align work with his volunteering activity, he persuaded his company to organize a marathon race on Sept 22 in the Olympic Green.

When talking about his public service work, he said volunteers serve as a bridge between the general society and vulnerable groups.

He Yajun, founder of the running group, said that without volunteer guides, the runners cannot even take the first step.

He lost his eyesight when he was 10 years old after a fever. He was depressed for several years and attempted a suicide. But he finally got through the dark times and started a business in Beijing as a blind masseur.

He started running in 2014 and completed his first overseas marathon in Barcelona in March 2016.

He said that running helped improve his physical condition and he became more optimistic.

"We are counting on the volunteers to guide us, they are our eyes and we rely on them", He said.

He noted that having a partner to exercise with pushed him to improve his fitness and also made him more aware of the surroundings.

He has been guided by Li many times. "Li is very professional and he runs fast", he said, adding that he feels happy to run with him.

When they run together, Li gives him professional insight like a coach, and in daily life Li is a caring friend, He said.

"He is serious during training", He said, adding that sometimes he can push the runners if he thinks they are slacking off.

"I hope more runners as well as volunteers join us," he said.