The Super Derby International Equestrian TREC Endurance on Silk Road kicked off in Zhaosu county, Xinjiang Uygur autonomous region, on Friday.

As the longest and most challenging equestrian event in China, the event has attracted a total of 71 riders from eight countries and regions, including the United States, Italy and France, to challenge their sporting limits, organizers said.

The youngest is only 14 years old while the oldest is 64.

The event's innovative fusion of equestrian endurance and orienteering features, adopting a multi-day segmented race format, presents unprecedented challenges to the physical fitness, intelligence, and collaborative abilities of riders and horses, said organizers.

The event, which will last until June 5, involves a professional category for a distance of 500 kilometers over seven days, and an amateur race spanning 220 km over three days.

The race tracks cover the vast grasslands, mountains, river valleys and other diverse terrains throughout Zhaosu county. And athletes must also face the huge challenges brought by the complex terrain, while enjoying the magnificent natural scenery during the competition, said organizers.

Coriou Andre, 64, an athlete from France, said he has only participated in endurance races of 100 kilometers per day for two days and mostly on flat tracks in the previous years.

"The '70 kilometers per day for three days' race at this Zhaosu competition , especially the altitude change of climbing over 1,000 meters on the first day and the continuous long-distance riding for several days is a new experience and a great challenge for me," he said.

Andre has rented a local horse to participate in the event.

Chinese American rider Jessica Zhai returns to compete here after more than a decade.

Zhai said she first participated in the Zhaosu equestrian endurance event in 2012.

"I found that I really enjoyed this sport after that, and I continued to participate in equestrian endurance event after returning to the United States," said Zhai.