Their bronzed bodies rippling with tension, gaggles of Chinese bodybuilders preened and performed press-ups backstage before competing for one of the country's biggest prizes in their discipline.
More than 100 men competed at a Bodybuilding Grand Prix this weekend for a top prize worth 80,000 yuan ($13,000).
They included at least 20 professionals as well as scores of amateurs from across the country, in what organisers said was a sign of the bulging popularity of muscle building in China.
"I am totally devoted to bodybuilding - I don't do any other job," said Jiang Min, 24, from northeast China, as assistants used rollers and brushes to daub brown make-up over his huge torso.
Wearing nothing but thongs, contestants grimaced as they contorted themselves under glaring stage lights in the central city of Zhengzhou, with an audience of several thousand people whooping in excitement.
"Chinese bodybuilders are now competing at an international level," said Gao Yan, a scientist turned gym entrepreneur who has run the competition for a decade and says it offers China's beefiest prizes.
But while men were encouraged to display huge muscles, in their own "Bikini Fitness" contest women appeared in skimpy swimsuits and high heels, and were judged by different standards.
"For men we look for muscle shape and definition... with women we look for wide-shoulders, small waist, and long legs," said Gao.
"We don't have women bodybuilders, we don't want women to be trained like that, like muscle women."
Contestant Svetlana Borushko from Russia's far east won a women's category but said: "Women don't get big prizes like the men... I compete because I like my body."
Bodybuilding has at least a century of history in China, but fell out of favour following the Communist revolution in 1949, when the sport was condemned as western and bourgeois and competitions sometimes banned.
But it has enjoyed a resurgence since the 1980s, and competitors said the growing number of contests made it viable as a way of making a living.
"There are more and more competitions and bigger prizes, so more opportunities," said Wang Yu, a 24-year-old amateur on the cusp of turning professional.
The winners were presented with oversized cheques - along with bumper-sized black tubs of protein supplements labelled "muscle powder".