The duration of the Shenzhou-13 crew's mission is six months, twice as long as the duration of the Shenzhou-12 crew. It's already been over two months since the Shenzhou-13 mission was launched. People on earth are curious about how taikonauts keep themselves mentally and physically fit. Professor Yang Yuguang from China Aerospace Science and Industry Corporation explains their fitness regime to CGTN anchors Zhong Shi and Li Dongning.