A Hong Kong comic series Jun Dao Sha Quan, or Military Boxing, once drew Premier Zhou Enlai as a martial arts master. It sounds far-fetched, but Zhou really did learn Xingyi boxing, a traditional Chinese form of internal boxing from boxing master Han Muxia.
Born in Tianjin in 1877, Han's experience was adapted into a kung fu film Wu Lin Zhi in 1990. When Zhou studied in Nankai University, Han was invited to give students martial arts classes. And according to Han's memory, Zhou was the most industrious student of boxing and achieved a lot during Xingyi boxing practice.
According to traditional martial arts theories, people who are good at Chinese internal boxing should be able to "sleep well while holding snow". In other words, they are not afraid of the cold.
Zhou had an excellent physical character due to his practicing of Xingyi boxing. It is recorded that Zhou only wore a woolen overcoat when he visited Moscow where people often wear heavy fur coats to protect them against the icy temperatures.