Just to be clear, this novel is not in any way related to Edgar Rice Burroughs or Barsoom. It was clearly a knock-off meant to cash in on the popularity of ERB's books.
I remember the following about the novel:
It had an off-white cover with a man fighting a green martian (but not an ERB green martian).
The novels production value seemed like a pulp-reprint, even though I read it in the 1980s. Probably reprinted in the 1970s, or so I thought at the time.
Man grows up next door to a French fencing master that teaches him how to sword fight.
He takes part in a teleportation experiment that takes him to Mars.
Adventures ensue, including a gladiatorial fight where the hero has to stall for time, so he slowly cuts his less-skilled opponent into hamburger.
Runs into an issue where he cannot marry the girl of his dreams if he kills her fiance. Some cultural taboo.
He eventually returns to Earth with only a few seconds passing, but coming back with scars from his adventure.