This article is from the Fencing FAQ, by Morgan Burke with numerous contributions by others.
Not if done properly. Although executed with appreciable energy,
a good, clean fencing attack hurts no more than a tap on the
shoulder. The force of the blow is normally absorbed by the flex
of the blade. Reckless and overly aggressive fencers can
occasionally deliver painful blows, however. Fencing *is* a
martial art, so you should expect minor bruises and welts every
now and again. They are rarely intentional. The most painful
blows tend to come from inexperienced fencers who have not yet
acquired the feel of the weapon.
The primary source of injury in fencing is from strained muscles
and joints. Proper warm-up and stretching before fencing will
minimize these occurences.
There is a risk of being injured by broken weapons. The shards
of a snapped blade can be very sharp and cause serious injury,
especially if the fencer doesn't immediately realize his blade is
broken, and continues fencing. Always wear proper protective
gear to reduce this risk. FIE homologated jackets, pants, and
masks are ideal, as they are made with puncture-resistant fabrics
such as ballistic nylon. If you cannot afford good fencing wear,
at least use a plastron (half-jacket worn beneath the regular
fencing jacket), and avoid old and rusty masks. Always wear a
glove that covers the cuff, to prevent blades from running up the
Fencing is often said to be safer than golf. Whether or not this
is true, it is an extraordinarily safe sport considering its
heritage and nature.