The Earth sport of swordplay with foil, épée or sabre, practised across the centuries by Starfleet officers including Hikaru Sulu and Jean-Luc Picard as exercise and as a test of wits.
Fencing survives as a pastime well into the age of starships. In The Naked Time (2266) Hikaru Sulu, his inhibitions removed by the Psi 2000 infection, runs bare-chested through the corridors of the Enterprise with a foil, imagining himself a swashbuckler, until Spock subdues him with a nerve pinch.
Jean-Luc Picard fences regularly aboard the Enterprise-D. We'll Always Have Paris opens with him in a bout against Lieutenant Dean when a ripple in time repeats the last few seconds, and in I, Borg he fences with Guinan, who feigns an injury to score a touch and make a point about pity for an enemy.
In the 2009 film Star Trek the younger Sulu names fencing as his combat training, and proves it with a folding sword on the Narada's drilling platform above Vulcan.