Convenience is essential in a fast-paced world where time is precious, Jiang Yijing reports.

Huang Rong used to work out at the campus gym during her college days and would use it at least five times every week. But after graduation and the commencement of a fast-paced life in Beijing, the 26-year-old found working out on a regular basis became problematic.

But help was at hand, literally. Huang turned to fitness apps. Now, with the guidance of a mobile phone app named Keep, she exercises five times every week for at least a half hour each time at home.

The fitness app, with videos, gives instructions for various exercises like yoga and push-ups. Every workout day, Huang opens the app and follows the instructor in the video.

"The best part of this app is you can do it anywhere, anytime. And you can set a notification on the app to remind you. Traveling to the gym is no longer necessary. I can work out more consistently," says Huang, adding she usually uses it at night and feels refreshed every time she finishes.

Another advantage of the app is that when she chooses her exercise target it can develop a personalized training program that meets her needs.

"My program provided me with different classes from day to day, which repeat periodically. All I need to do is to follow its plan and instructions. The app is like a personalized instructor, and the videos explain every movement clearly. More importantly, all the classes I use are free."

Huang relished the workout experience with the app so much that she recommended it to a colleague, who claimed that he lost five kilograms after a month's exercise.