Holger Chen or Chen Chih-han (traditional Chinese: 陳之漢; simplified Chinese: 陈之汉; pinyin: Chén Zhīhàn; born March 12, 1979), is a Taiwanese internet celebrity, entrepreneur, political activist and mixed martial artist. He is also known popularly as Kuan Chang (Chinese: 館長; pinyin: Guǎnzhǎng; literally "gym manager") in Taiwan, being the founder and CEO of G.K. Fitness Club (成吉思汗健身俱樂部), named after Genghis Khan. As an actor, Chen had his first appearance as a cameo in the 2008 film Parking. He is referred by some as the Joe Rogan of Taiwan.