I'm trying to find an asian (I think) movie that I watched when I was a kid back in the 90's. The movie itself may be from the late 70's -80s. It had some crazy fights in mid air and what-not, it was a very cheesy movie.
All I remember was one average guy that was trying his best to get into a martial arts school, where he worked as a janitor. Their members (the good guys) looked very strong, possibly bodybuilders (or at least that's how I recall it). They used to practice all kinds of exercises to become more powerful. The sensei of the school would not accept the main actor into his school at the beginning, but after a while he got persuaded into it. At the beginning of his training he was very weak (I think I remember the sensei touching our guy's flabby abs), but after a while he became very powerful.
In the end he was strong enough to fight the bad guy (might be someone's son from a rival martial arts school) and defeat him.
I don't remember what the main plot of the movie was, this is all I remember. Thanks in advance