I believe that movie came out just before the advent of the “PG-13” rating. Usually excessive sex, violence, and/or profanity (particularly F-bombs) were required to get an R rating prior to that time. For example, one of my favorite movies, “Emperor Of North” (1973), has every cuss word except the F-word and some bloody moments as well and was rated PG. All of the James Bond movies were also rated PG until “Licence To Kill” in 1989. Since then, they have all been PG-13.
Apparently some movies want that “R” rating.
I watched “Chariots of Fire” and saw nothing which would have kept it from being a G rating. Then maybe the third or fourth time I saw it, I noticed a very quick shot of a guy completely away from the action in a shower. Just a second of so of his back. That had to have been put it in just to get the “R” rating.