Fencing weapons are not “weapons”. Although we constantly call our fencing equipment with the words “weapon” or “sword”, these are pieces of sports equipment. They are specifically designed to not harm anyone. Assuming you're wearing the right equipment, it really isn't.
It may be a little jarring at first (especially the mask strokes), but it doesn't really hurt. Strong blows in bare areas can leave marks, but I think they are on par with any other cuts and scratches. Fencing requires a lot of mental agility, probably more than any other sport, but along with that, fencing also needs power, balance, dexterity and motor skills. The sport strictly requires protective equipment for all fencers involved in any fencing activity, and is standard in all fencing schools.
Fragments of a broken blade can be very sharp and cause injury, especially if the fencer does not immediately notice that his blade is broken and continues to wield. Contrary to what Hollywood movies have represented, in modern fencing the blade of the sword is not sharp. It makes me want to create one or two characters who make fences in order to use this wealth of information. Sometimes, when you're wielding a really good opponent, you don't even feel the punches because he knows exactly how much pressure it takes to get the point.
I wield the sword recreationally, and I came across this page while I was searching the web trying to determine how much rest I should give my somewhat tender Lateral Collateral Knee Ligament of my hind leg. Fencing jacket and pants (also called panties) are typically made from a combination of materials including cotton, ballistic nylon, kevlar and more. When someone mentions fencing and injuries, the first thoughts that come to mind are probably bloody stab wounds. A danger of saber fencing is that when an opponent attacks with too much swinging motion, the blade is flexible and can hit the protection of the weapon, shoulder or mask.
This interpretation that fencing training equipment does not produce injuries can be traced back to the origins of fencing in large schools in Europe. If the fencing action gets too close, sometimes a fencer will inadvertently hit the guard of his weapon against his opponent's mask. It never ceases to amaze new students how easy and painless fencing feels compared to what they expected.