[Photo provided to China Daily]

As a veteran marathoner and cross-country runner who has covered a lot of terrain, Yun Yanqiao was still taken aback by Yading.

Yading is in Daocheng county, Sichuan province's Garze Tibetan autonomous prefecture and known for its mountains and natural scenery.

The 30-year-old Yun was there to participate in a cross-country event in May. He opted for a 46-kilometer race and a 10,000-meter hike on the side.

"I've been to races where only one section is on a relatively higher level before, but in this half of the race is at more than 4,000 meters above sea level on average," says Yun.

The two highest mountain passes are both around 4,700 meters, and physically challenging for Yun.

"The altitude, plus the big ascent－I felt exhausted and was about to collapse," he says. "Only those with experience will understand what I felt."

In April, Yun had won the first mass marathon gold medal in the 58-year history of China's National Games in Tianjin. He was also a two-time winner at the Vibram Hong Kong 100 Km Ultra Trail Race.