Editor's notes: Regular exercise is an essential part of a healthy lifestyle. But the outbreak of the novel coronavirus has kept millions of people from partaking in outdoor activities since late January. Since then, indoor workouts have become an important way to keep healthy and protect against illness, especially during a critical time like this.

In this series, we're showing some of the most popular traditional Chinese indoor exercises which have been practiced for centuries, and proven effective for health and fitness.

This photo shows an illustrated explanation of the Shaolin-style twelve-stance Yi Jin Jing qigong exercise in standing posture. There exist other versions of Yi Jin Jing in sitting postures. Both are easy to learn and suitable for the office, the home and even a hospital ward. [Photo/tmall.com]

Yi Jin Jing

Yi Jin Jing, literally meaning “muscle-and-tendon-transforming sutra”, is a traditional qigong exercise most people first get to know through wuxia (martial arts) fiction by Hong Kong novelist Jin Yong , aka Louis Cha Leung-Yung.

He used the kung fu sutra in the plots of two of his well-received Wuxia novels: Xiao Ao Jiang Hu, aka Smiling Proud Wanderer, and Tian Long Ba Bu, aka Demi-Gods and Semi Devils.

Both have been adapted into TV and film hits several times in Hong Kong and the Chinese mainland since the late 1980s.