As China’s economy develops, authorities are racing ahead with their efforts to promote long-distance running – but a calamitous marathon in south China has raised questions over whether Beijing is pushing forward at too quick a pace.

Thousands of people were injured while running a marathon on Sunday in Qingyuan, a city of some 3.7 million people in south China’s Guangdong province.

According to local newspaper Qingyuan Daily, medical workers performed first aid on participants more than 12,000 times, treating 10,000 muscle spasms and 1,700 sprains. Ambulances were called in 23 times and 17 people were hospitalized, including five in critical condition, the newspaper reported.

A spokeswoman for the Qingyuan health bureau confirmed the statistics to China Real Time. She wasn’t able to give a figure for the total number of people injured but said it is likely less than 12,000, as each individual could have received more than one instance of treatment.

A spokesman for the Qingyuan marathon declined to comment beyond praising the work of medical personnel. “If they performed 12,000 treatments in five hours, I think this is quite an accomplishment,” the spokesman said.

Marathon running is booming in China. A total of 134 marathons were held in the country last year, 83 more than in 2014, attracting 1.5 million participants, according to data from the Chinese Athletic Association.

The proliferation of events is part of an ambitious program rolled out in 2014 by China’s state council, or cabinet, with the goal of boosting the country’s sports economy to a value of 5 trillion yuan by 2025—a 15-fold increase.

Local governments like to host marathons because they can bring cities prestige as well as tourist dollars and official funding, experts say. In 2011, for example, the city of Lanzhou, which sits along the Yellow River and China’s ancient Silk Road, received 400 million yuan ($61 million) from Gansu provincial authorities to revamp its roads ahead of its first marathon, according to China News Service.

The races can also be big business for the firms that organize them: In its interim report in 2015, Wisdom Sports Group, a Hong-Kong listed company that specializes in hosting athletic events in mainland China, said it raked in 66.9 million yuan ($10 million) gross profit in the first six months of last year from running events, posting a 62.6% gross margin.

But the marathon craze has also been marked by grave mishaps as inexperienced organizers scramble to host races – and inexperienced runners enthusiastically sign up to race them – with experts increasingly worried about flaws in race management and participants’ poor knowledge of their own health conditions.

Five participants died while running in Chinese marathons in 2015, according to a Chinese media tally.

One expert told the state-run Global Times newspaper that for each race, marathon organizers should deploy at least 40 automated external defibrillators, or AEDs, in case runners experience cardiac arrest. But even some big cities in China lack the proper number of devices, and some organizers say they can’t afford the cost, the expert told the paper.

The marathon push is resonating among a Chinese public devoting more time and money to physical fitness thanks to China’s economic gains. According to a consumer survey released by Nielsen in December, running was cited as the favorite sport of 71% of Chinese men and 69% of women, trailed by badminton and swimming.

Marathon registration slots can be snapped up in hours in major cities, with scalped tickets often selling online for ten or even twenty times the original price.

Tao Shaoming, who coached China’s national long-running team for ten years, said most people who have consulted him on running marathons asked not about training, but about injuries.

“To my surprise, a lot people thought they could just run, but they never thought about how to run more scientifically,” Mr. Tao told China Real Time.

In the case of the Qingyuan marathon, the organizers’ lack of experience was also on display when it came to the gift bags given to runners. According to local media, organizers gave runners bars of grape-scented soap, which many participants mistook for energy bars and attempted to eat.

Photos posted online by race participants show the packages of soap were decorated with an image of succulent grapes, along with the words “fruity soap” and “extra moisturizer” written in English. There was no Chinese-language explanation on the package, which may have contributed to the confusion, many online commenters lamented.

The drama drew a deluge of comments on social media. "Running a marathon is not like going to the farmer's market; it’s not for everyone. These people should know their limits,” wrote one user of China's Weibo social network.

“Now you know the importance of learning English,” wrote another, in a mocking comment about the soap drama.

A spokesman for the organizers told the Qingyuan Daily that their original intention was for runners to be able to go home and take a comfortable shower after the race. The spokesman added that the organizers regretted that the product wasn’t labelled in Chinese and said that of all the complimentary items in the gift bag, the imported soap was actually the most expensive one.

--Pei Li. Follow him on Twitter @teamlipei.