The sport of fencing engages the entire body, even the parts that are not targets or directly involved in scoring. Feet are especially critical, and to illustrate this idea I’ll use video I recorded at the recent NCAA Championship. (You’ll see the back of a lot of heads; I’m a fan, not a professional.)
As the footwork is very different for the three weapons, they’ll each get their own example.
In foil (where touches are scored with the point of the blade only, and the target area is limited to the torso), the feet are constantly moving, either forward or back. The fencer advances not only to come within striking distance, but to probe for weaknesses. Retreats can also be used strategically, as shown in this video. Notice how the fencer on the left comes in close and flicks his blade at the opponent, hoping to elicit a reaction; he then abandons his attack and moves backwards, drawing in the fencer on the right, who advances too far and gets hit with a perfectly timed attack from the left.
If foil is about constant back and forth, epee (touches scored only with the point, but the target area is the entire body) is about waiting. Epee fencers bounce on the balls of their feet as often than they advance or retreat, looking for an opportunity to attack. In this video, the fencer on the right matches the steady rhythm of his opponent, and strikes when the fencer on the left extends himself too far.
Nether the strategy of foil nor nuance of epee is anywhere to be found in saber (touches scored with any part of the blade, and the target is anywhere from the waist up). Don’t think — just go. Both fencers show remarkable athleticism in this video, and I’m not sure which is more impressive: the leap from the left, or how the fencer on the right was able to stand up after he ends up like he does.
I’m not going to reach the level of expertise I witnessed at the NCAA tournament, but I came away convinced more than ever that you fence with your feet.