"We had to go back to Chengdu, the capital of Sichuan province, due to the virus as we couldn't get enough food supplies when the shops closed," Liu said.

The team stayed in Chengdu from Feb 5 until the middle of March. Liu was worried his physical condition would decline because of the lengthy enforced rest period and did exercises inside the hotel to try to stay fit.

On March 15, he resumed his journey in Kangding, another city in Sichuan, where he had stopped his trip. The remaining distance to Lhasa was 1,800 km.

Liu said he was focused on the remainder of the journey but didn't feel well in the beginning as he was unable to do high-intensity training in the hotel. However, he quickly improved after two days of running.

"I began running 15 years ago, so I know how to adjust my body," he said, adding that because he had been prepared for running at high altitudes and in extreme weather conditions, it was not daunting in the mountainous terrain.

Liu said his determination also helped him complete the run. "Once a task is set, I definitely finish it despite the difficulties and challenges," he said.

Liu livestreamed his journey every day on the video-sharing app Douyin, which helped him make many friends.

"They gave me plenty of support during the tough process and I think it was the biggest reward for me," he said.

On his return home he intends to concentrate on his business and will continue running.

Qin Jirong in Hangzhou contributed to this story.