Behind them, one of the slogans on the two-storey school building reads: “Enjoy happy education”.

They call the dance guibu, or ghost steps – a shuffle dance incorporating modern jazz steps, with heel-and-toe movements and arm actions.

But this is not a typical schoolyard scene in China. Elsewhere, students can be seen going through the motions of their daily callisthenics routine – a rigid workout that has been a requirement at every primary, middle and high school since 1951, whose origin can be traced back to 19th century Germany.

The Chinese version, known as broadcast callisthenics, was based on exercises used by Japanese soldiers during the second world war, with modifications “inspired” by routines used in the former Soviet Union, according to state media.

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With recorded instructions played over loudspeakers and music blaring, students are directed to exercise in synchronised movements – bending, stretching, jumping, turning – with the aim of improving strength, flexibility, agility and teamwork.

In the past, it was also part of the work day at state-owned factories and government bodies, but now it is compulsory only in schools – unless the weather or air pollution is too bad to exercise outside.

Government inspectors even carry out unannounced checks at schools to make sure the routine is being followed, according to the Ministry of Education.

But school principal Zhang told Southern Metropolis News last week that he and his 700 pupils needed a change. “I wanted to introduce the [shuffle] dance … because the students and [teachers] had no interest at all in the broadcast callisthenics,” he was quoted as saying.

He said half of the teachers at the school had opposed the idea when he began the new exercise routine in November. But after two weeks they were joining in “because the music is full of energy … it really gets the happiness flowing”, Zhang said.

The school principal said he had not expected the videos he posted on social media to generate so much interest. “This is just a small activity at our school – I just wanted to offer a different way to exercise during the class break,” he said.

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But after abandoning the government-imposed callisthenics programme altogether in December, some internet users feared that Zhang could lose his job over it.

“This could be the end [of his career] once all the attention is over,” read one comment in a discussion forum on Baidu Tieba.

Zhang could not immediately be reached for comment on Sunday, while the ministry and county education authorities did not respond to queries.

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In Linyi county, locals were divided on the principal’s move.

“The official exercises are based on science – they must be good for the students or the government would not have enforced it for so long,” said a hotel manager who declined to be named.

A mobile phone shop owner disagreed. “The priority is to get the kids moving, so they won’t spend all day reading books, watching television or playing on their phones,” he said.

Changing diets and an increasingly sedentary lifestyle among the middle class has seen a rise in childhood obesity in China. Peking University’s School of Public Health has estimated that 28 per cent of children in China aged between seven and 18 – or almost 50 million children – will be classified as obese or overweight by 2030.

In Beijing, a primary school pupil in Chaoyang district said he was envious after he watched the video.

“This is so cool – I hope our school can do it,” said nine-year-old Zhang Yu, adding: “Broadcast callisthenics would be good for robots or zombies because they don’t feel bored or anything.”