Every martial artist wants to be fast; the faster you are, the better you're going to be at hitting the other person while not getting hit yourself. The questions are, what is speed, and how do you train for it? Martial arts speed is not the same thing as speed for a marathoner or for a 100 m sprinter.
I was listening to two podcast interviews about speed training and realized that part of the problem is people thinking the wrong way about speed - seeing one attribute and thinking that it means the person is fast, when in fact it doesn't.
The first interview was with Mike Boyle on the Strength Coach Podcast (which I love). I can't remember which episode, but he was talking about training hockey players, and how he introduced a test where he timed how fast they could skate across the rink. What was interesting was that his results didn't match what the coaches thought of their own players. There were players who seemed slow but actually got across the ice quickly, and players who seemed fast but weren't actually getting across the ice fast.
What was the difference? The players who were thought to be fast but weren't tended to have fast, quick movements with their feet. Their feet were moving around a lot, but that wasn't necessarily translating into higher velocities in the rink.
Think about hockey - you want players who can get from one side of the rink to the other quickly - move their bodies along the ice quickly - not just move their skates fast. But fast moving skates makes someone look fast, so that's what the coaches were thinking about. Until someone came along with a stopwatch and actually timed how long it took to get from blue line to blue line (or something like that, I'm not a hockey guy).
The second enlightening interview, this one on the Just Fly Performance Podcast but I can't find the episode, was with a track coach talking about how useless agility ladders were for speed training.
Agility ladders are a common tool for speed development. They look like a ladder made of ropes or thin chains, laid out on the ground, and people either run through them or do little drills - hopping side to side, trying to get their feet to move faster and faster through the squares set up by the ladder.
The coach (again, sorry I forgot his name) found that players who did a lot of agility ladder work didn't actually get faster at moving their bodies, just their feet. In fact, the ones who did the most on the agility ladder got slower. What do I mean? They got good at having their feet dance around, left to right, in intricate patterns, but worse at actually accelerating their center of mass.
Watch some video of agility ladder training. In a LOT of the drills, the trainees are moving their feet really quickly, back and forth, often changing direction really quickly. Now watch the video again, and pay attention to the center of their body - somewhere around the sternum. Is that part moving fast, or are the feet just dancing around?
Having quick feet isn't a bad thing, but it's not that valuable to a martial artist (or a football player, or a soccer player, or really almost any kind of athlete). What you WANT is to be able to quickly accelerate and decelerate your center of mass - get your body moving fast, then stopping, then moving back the other way. If your feet are all over the place but your chest stays relatively still, your'e not going to be able to escape an attack or get yourself into position to counterattack. Imagine someone coming at you with, say, a front kick to the solar plexus. What's important there - having fast feet or getting your torso out of the way?
But, being able to fly around an agility ladder LOOKS impressive. It looks fast. And that's the problem.
I do not want to recommend a complete speed training program at this point - I have some ideas, but nothing definitive. I'm pretty sure that something like kettlebell swings and some work with minibands will do a lot more for your combat speed than running through an agility ladder routine.
If you are thinking about an exercise, and wondering if it will help speed, here's a quick list of things to think about:
1. Does the drill involve moving your body (the center of your torso)? It should!
2. Does the drill involve more than two steps in any direction? It shouldn't! Fighting speed is how fast you can take one or two steps, no more.
3. Are you doing the drill at maximum speed and force, or does it last so long that you pace yourself? Speed drills should be done fast an explosively. If you're pacing yourself to get through it, it's not going to make you faster (though it might be improving your endurance).
In short, agility ladders might be good for a warmup or a supplement to speed training, but they shouldn't be your primary tool. To get faster, get better at putting larger amounts of force into the ground, quickly.