Instructors' new platform

Apps are also seeing fitness instructors diversify their methods of teaching. Many instructors have found opportunities to teach classes on the apps for a fee.

Li Yu is a fitness and boxing instructor. Persuading people in a gym to take boxing classes is not an easy task for him. Moreover, boxing is not a sport with wide public appeal.

But in the past six months, more than 5,000 people have taken part in his boxing classes on the app.

The 37-year-old started to use the app out of curiosity in June 2016. As a fitness instructor, he used it to post his photos after exercising. A military veteran who served for five years, Li knows a lot about how to work out and box. The content he posted always related to training skills and quickly received many "likes" from other users.

"I'm not good at talking proactively to people in a gym, but on the social platform with people's 'likes', I tend to share more of my training and boxing know-how," says Li, who became a "key opinion leader" with 496,000 followers.

However, the instructor was not satisfied with just sharing tips and photos. Li also wanted to launch his own class on the app to share his knowledge and skills with his followers. In June, Li developed his app boxing class, with videos of 10 sessions. It costs 46.9 yuan ($6.90) and buyers can watch it as many times as they want.

On the app, the price is not cheap considering that most paid classes charge just 20 yuan, and many are actually free. Li thinks his success is due to the large number of users on the app.

"People who practice boxing are usually sports enthusiasts. There are many potential users on the popular fitness app. Compared to talking to people in person at a gym, introducing boxing on the app's social platform can be more direct and efficient," says Li, who also stresses the importance of professional advice when doing any exercise.

Contact the writer at jiangyijing@chinadaily.com.cn