Hundreds of athletes as young as seven are undergoing military training in Shanghai designed to instill discipline and "good fighting ability", the Chinese city said.
The athletes will "deeply study" the Chinese military's "sense of standards and combat spirit", Shanghai's sports bureau said.
Chinese football teams have previously undergone similar training, which is largely performative and part of a wider campaign to promote Communist Party values.
President Xi Jinping said this year that China must enhance its readiness for "actual combat".
He Youxiao, head coach of a men's gymnastics team participating in the training this week, said that the age range of his athletes spanned from seven to 25.
"No matter how old or young, everybody deeply cherishes this opportunity," said He, according to a news report by the sports bureau.
The training started on Monday and is scheduled to last until next Tuesday. It involves 932 athletes from 11 sports centres across the city.
It is intended to "strengthen the sports teams' organisational discipline and teamwork, helping Shanghai sports create an iron army", said the report.
"From dawn until broad daylight, the athletes move neatly and in unison, their youth military uniforms showing off a young and elegant manner."
China last month adopted a new education law seeking to impart a "patriotic spirit" in China's youth, according to state media at the time.
