According to director Terence H. Winkless, the original script had Don Wilson's character training by running up stairs of a temple. When he arrived in the Philippines to begin shooting no temple could be found. A live volcano was nearby so he changed the script to have the character training by running up a live volcano as it would make an interesting replacement for the temple.
The mountain that Don Wilson runs up is actually an active volcano, and the shot of Wilson standing at the summit was actually filmed at the volcano's vent. Wilson describes the filming as genuinely dangerous and claims he would not repeat the scene today.
Out of all 9 Bloodfist films, Bloodfist II (1990) is the only sequel that has any connection to this first film as Don Wilson plays the same character Jake Raye. All the other sequels (except for the Wilson-less Bloodfist 2050) have Don 'The Dragon' Wilson playing different characters.