"There is nothing better than doing a workout there when I finish my daily work. I feel unwell if I don't exercise for one day," said Xu from Ma'anshan, Anhui province, who runs an online store and works from home.

Fitness app Keep offers those with paid memberships livestreamed exercise classes. While watching such livestreams, users can post "bullet screens"-real-time comments that appear on the screen-to cheer on each other and ask questions, which the coach answers to ease any doubts.

"I love to watch such livestreams because of the immersive atmosphere that encourages you to persist. It's difficult to complete the challenge on your own, especially for hard training like indoor cycling," Xu said.

If someone posts that he or she can't keep up, the coach and other users will encourage them. Xu never watches the playback because such heartening "bullet screens" only appear on livestreams.

Special bracelets

Those who wear a Keep fitness bracelet can learn about their realtime heart rate and the number of calories burned. However, while only those who tip the most will see their names on the ranking list of livestreams, the rule is different in livestreamed fitness classes-you have to exercise hard to achieve that by burning the most calories.

"It's very encouraging to see my ranking go up gradually on the list on the screen. You can also team up with friends to compete in groups," Xu said. "Bodybuilding is not a passing fad. The key to persistence is to have a relaxed attitude rather than being anxious. I always tell myself that I'm not losing weight, I'm just taking some exercise."

She suggested that starters should choose simple exercises they can stick to until they have formed the habit. She added that they should not be in a hurry to succeed, and that peer encouragement also works. She has a WeChat group with friends to share their routine exercises.