Muscle. According to Baidu Encyclopedia, under weightlessness, the muscles of human body will contract, leading to the decline of body function. Penguin clothing is a special kind of clothing, which is equipped with many elastic bands. Through pressure and restraint, it simulates the load of human body on muscles when moving on the ground, so that astronauts' muscles can be exercised and stimulated, maintain their basic structure and function, prevent muscle atrophy, and improve astronauts' physical quality and adaptability.