This is a movie from the 80s or 90s, I am leaning towards 90s. The movie is in english and from what I recall semi low budget so I can’t remember any actors.
Main character met a pro wrestler/fighter etc as a child and the wrestler gave him a keepsake (might have been a medal, or a picture) Fast forward, main character is grown and goofs off practicing his martial arts in a warehouse on boxes or something like that. Gets discovered and is subjected to cutting edge training in a weird room so as to have a chance against his opponents. There might also be performance enhancing drugs involved. The bouts are all pretty much full contact and the fighters don’t seem to have alot of animosity towards each other after the fights are over, near the end the main character becomes a big deal in the organization, one of his co fighters that he considers a friend (the friends stage name might have been budda guy or budokai?) is put into a fight to the death against a crazed drug enhanced fighter that might have been wearing a shock collar to keep him in check, there’s a cage i think and weapons maybe involved, the friend is killed by the crazed fighter who turns out to be the main characters childhood hero from the beginning of the movie, main character is forced to fight his hero, he shows him the keepsake and the crazed fighter mellows out and seems like hes in a trance remembering his former self before he is killed by the main villain…..good guy goes onto win etc etc.