[Video/Official Sina Weibo account of China Manned Space Agency]

What is it like to exercise in space? Simple things can be harder in microgravity, while difficult tasks might suddenly be a breeze. A video released on Tuesday shows Zhai Zhigang, a crew member of Shenzhou XIII, practicing tai chi on the Tiangong-1 space lab module with flowing and graceful movements.

The three taikonauts Zhai Zhigang, Wang Yaping and Ye Guangfu have been in orbit for about a month since they began their six-month mission to build the space station on Oct 16. Chinese netizens have long been curious about what really goes on inside the space station. While people were still amazed by Wang Yaping's zero-gravity hair style, Zhai showed his "flying" skill and was obviously good at it.

In fact, the tradition of Chinese astronauts practicing tai chi started in 2012 when the country's Shenzhou IX crew member Liu Yang first did so in space and called the experience comfortable.

For space travelers, fitness is a top priority. They must exercise to counter the gravity-free conditions as the experience of "muscle and bone loss" in space will affect their health and ability to work in the long term. Before returning from the Shenzhou XII mission in September, taikonaut Nie Haisheng also practiced tai chi on board the Tianhe core cabin during an Earth-space video call with Hong Kong youths.

Apart from doing tai chi, Chinese taikonauts also play ping pong, ride a stationary bike and run on a treadmill to help train their breathing.