Running on Karma, also known as An Intelligent Muscle Man, is a 2003 Hong Kong action thriller film produced and directed by Johnnie To and Wai Ka-fai. The film is ultimately a Buddhist parable about the nature of karma. There were some cuts in the Mainland China edition to meet the requirements for release there.

Wai Ka-fai is a Hong Kong filmmaker. Best known for his frequent collaborations with Johnnie To, he co-formed Milkyway Image in 1996, which is now one of the most successful independent film studios in Hong Kong.