"Health is kind of the new wealth in China," said one athletic apparel executive. Yangshuo in southern China has long been a rock-climbing destination for American and European tourists. But lately, a different demographic has flocked to its limestone cliffs: office workers from China's big cities.

"I needed some exercise and outdoor activities to cope with the high-pressure work environment," Chen Xue, a 28-year-old auditor from Chongqing, said on a recent cloudy morning, one of a half-dozen climbers clustered around a cave looking out at Yangshuo's jade-green mountains.

China's rock-climbing boom is part of a larger fitness craze. The number of marathon participants has doubled since 2017 to more than 1 million people, and finishing times are getting faster, according to the Chinese Athletics Association. Hyrox, a strenuous fitness competition involving 1-kilometer runs and strength challenges, had 55,000 participants in China this past year, up from 7,300 a year earlier.

Novel racket sports like padel are spreading; the small central city of Hebi has built around 1,600 pickleball courts and has roughly 300,000 pickleball players, according to state television.