He added that the craze for exercise and keeping fit and COVID-19 are not a completely casual relationship, but the epidemic has spurred the online fitness market. It has caused some offline gyms to go out of business, so coaches have been providing fitness content online.

In April, Liu Keng-hung, a celebrity from Taiwan, and his wife became a craze online due to their livestreams of strenuous exercise with the background music of Taiwan singer Jay Chou.

Liu's account on short-video platform Douyin saw an increase of nearly 40 million fans to about 46 million.

"Liu's extreme popularity means that the nationwide demands for physical fitness have been stirred up. It also means that there are opportunities for those in the online fitness market. Hopefully, more fitness influencers will draw people's attention in the future," Hai said.

Services for seniors

It's not uncommon to see Chinese seniors doing various workouts in parks, such as brisk walking, playing diabolo, shuttlecock and tai chi. Some short videos that have gone viral online show some advanced exercisers doing pullups on the horizontal bar in public.

For most female Chinese seniors, the best exercise is undoubtedly square dancing, during which they can also rub shoulders with their peers.

Qiu Meixia, 59, of Danyang city, Jiangsu province, is an exception. In November, Qiu's daughter-a regular member of HiLefit, a 24-hour gym chain based in Hangzhou, Zhejiang province-bought her a membership that allows her to enjoy online private coach sessions via HiLefit's app.

The retiree takes two one-hour sessions per week via a video chat with her private coach, who organizes a set of scientific workouts in accordance with Liu's condition and demands, and corrects her movements if she does things incorrectly.

"My aim is to tone my body. It's very convenient to do workouts at home, which are arranged according to my schedule. A coach's supervision helps me overcome inertia," Qiu said, adding that she also does yoga on her own.

"You can ask questions at anytime, and the coach will ask about your physical condition, or whether you've had a meal before each session."

Liu only did stretches when she exercised on her own, but now she's learned about strength-training movements, cardio activities and also the importance of warmup exercises.