Slide, jab, reverse. Jab, step, reverse. Jab, kick, jab. Turn around.

It’s Wednesday night at the dojo, and we are practicing sparring combinations. Back and forth across the floor, in two neat lines of white uniforms, sliding, stepping, punching, kicking. It’s fairly peaceful, apart from the heavy breathing, and the kiai (shout) on every tenth technique. Our dojo has a glass wall in front and the odd passerby pauses curiously outside, wondering what on earth we are so worked up about. It does look a little peculiar, like we are fending off invisible mosquitoes, or possibly mountain lions. It doesn’t look much like fighting.

Much of our practice for sparring, or kumite as it’s called in karate, is done without a partner. It has to be. Sparring partners aren’t easy to come by and if you hit them a lot, they break. So even though we are learning to fight an opponent, we do the bulk of our training solo. We have to imagine our opponents. That takes practice, and until you can really visualize the imaginary person you are fighting, as if he or she is right there in front of you, sparring class can feel kind of strange and pointless. Once you’ve got the image solidified in your mind, it gets a lot easier. Admittedly, it still looks pretty weird.

You build the image of your mental opponent by working with real partners on drills and scripted exchanges, and in carefully controlled free-sparring rounds. As you gain experience, the partner in your head gradually takes shape as a composite of every person you work with.

Bits of other people can get conscripted into your mental opponent too—schoolyard bullies and workplace rivals are there in the mix for me, and siblings and bad bosses and cartoon supervillains, and probably a few random Nazis I remember from the movies. A vivid mental opponent can really liven up a sparring class, let me tell you. Who can you imagine yourself punching? I’ll bet you can think of someone.

Your imaginary opponent can dredge up unpleasant memories too, especially early in your training. When you first get started, you haven’t had a chance to work with a lot of serious karate students, people training for your benefit as well as theirs. Bogeymen and past opponents—who maybe didn’t have your well-being in mind—tend to dominate the image. For survivors of violence, the process of imagining an attacker can be quite distressing. So working with a range of partners is important as you move into sparring. They help you build your memories of positive interactions. Over time, you envision less of the bogeyman, bully, or personal enemy, and more of your training partners.

On Wednesday nights, we do partner work after we finish our combinations. We pair up, and we bow. We finish an exercise, and we bow again. We change partners, we bow. Bowing is important. And even though we bow a lot, you can’t phone it in. You have to stand in a proper stance, look your opponent in the eye, bow, and say “Osu!” (Osu is difficult to translate. I usually tell people it corresponds roughly to saying “Amen!” in church.) Your partner is giving you help you can’t get from just anyone—trusting you, testing you—so you have to thank him or her properly.

Tonight our partner exercises happen to focus on evasion and countering. This is foreign territory for me, and I go into it with the air of a sacrificial victim. A few years ago my dojo, which had previously been unaffiliated, joined a worldwide karate organization. Our new style puts more emphasis on defensive tactics. Or perhaps I should say, our new style has defensive tactics.

In our old system, we learned basic blocks, but there wasn’t much discussion of, say, positioning yourself for follow-up techniques. The assumption was that if you had to hit someone twice, you didn’t hit him hard enough the first time. It was not perhaps the most artistic way to practice the martial arts, but from a woman’s self-defense perspective, it was practical. I’ve found that most men don’t expect women to fight like that.

But the art and spirit of karate demand something more subtle and so, as I said, we now do a lot of training on strategic footwork—moving to the outside of some techniques, to the inside of others; closing up your opponent so she can’t effectively strike, while simultaneously exposing as many of her target areas as possible. These tactics are elegant and logical but unfortunately I spent an awful lot of years training myself to rush headlong at people and hit them very hard, as quickly as I could. That didn’t come naturally to me (I like to fight, but I’m not suicidal) and I really had to hard-wire it into my body.

Now I’m supposed to observe and react, and boy am I bad at that. The really frustrating thing is, I’ve been training long enough that I can see techniques coming. I can anticipate a kick by the way my opponent shifts his upper body. I can time a punch by watching her eyes. But I can’t seem to do anything about what I see, other than rush-in-and-hit-them-very-hard-as-fast-as-possible. Trying to do anything else, like shift to the outside, block, and counter-attack, takes me, I’d say, about eleven minutes. Feels like it, anyway.

Luckily my partners possess boundless patience and are kind enough to pretend they don’t hear me swearing under my breath: Step to the outside, don’t slide, damn it; move that foot, not this one. They act as if they really believe I am going to get the hang of it one of these days, and I am grateful for their optimism.

After partner drills, class proceeds to free-sparring rounds. Again, we pair up; we bow. Usually our rounds last only two minutes, so we can work with as many partners as possible. Also to give everyone time to breathe. Boxing rounds last three minutes, but boxers don’t have to kick. It makes a difference. Even in two-minute doses, free sparring is the most strenuous thing I’ve ever done, and I’ve given birth twice. No one in the delivery room tried to hit me in the head, plus they gave me oxygen. It was pretty damned sweet. Much easier than sparring.

Also, when I gave birth, no one cared about my technique.

There is a lot of technique associated with kumite. You won’t be surprised to learn that none of it does me much good. For example: When sparring someone taller than you, you often are advised to “get in and get out”—move in and hit them, then move out of range. This sounds good in theory, but in practice I’ve found that it just gives the tall person twice as many opportunities to hit me: Once on my way in, and then again while I’m moving out. So usually I just try to get past their guard once, and then stay there, close in, and guard my head the best I can while I slug them.

This isn’t elegant but it works better than you might expect. For one thing, a lot of tall people are accustomed to outfighting, casting the net of their long arms and legs as far as they can and doing their damage at a safe (for them) distance. Confronted with someone up in their face they are often at a loss. Also, really tall people find it difficult to land a punch at close range—their arms are too long. Sometimes they’ll resort to raining blows down on the top of your skull, which isn’t a legal target, but I can understand the impulse.

Sparring tall people is frustrating, but dear god in heaven I hate sparring short people. Short people kick hard—in my experience, short women kick even harder than short men—and the only surefire way to avoid their kicks is to move around a lot and make them chase you. The bigger and more powerful they are the quicker this works, because they get tired. But so do I. If I wanted to run, I’d have chosen a sport that required shoes.

I can suck up punches pretty well, but a kick, if it lands, is really hard to shake off. The physics just don’t work out. Kicks come more directly from the ground than punches. They are braced, so to speak, against the earth. They utilize heavier, stronger muscles and longer bones, and the person kicking is much more likely to have their center of mass behind a kick than they are to have it behind a punch. Trying to absorb that much power doesn’t make a lot of sense. Trust me, I’ve tried.

What does work is to jam or grapple the kick, which I love doing but which isn’t exactly kosher in my style of karate. Black belts are allowed to sweep an opponent if we do it safely and cleanly. Grappling is not clean. The instant you grapple someone they become your problem in a very immediate way. Their weight, strength, momentum, and state of mind are all suddenly your responsibility, so you’d better have a plan for what to do with them: A joint lock, a dynamic throw, or (not during sparring, obviously) a brick wall to shove them into.

My problem is I never have a plan. I’m a grappler by instinct, not by training. I was the youngest of five children and I got jumped and sat on a lot, and I was small for my age for many years. Thus I developed a tendency to squirm, pinch, bite, throttle, claw, and generally do whatever it took to minimize my size disadvantage. To this day my older sister carries a piece of pencil lead embedded in her knee thanks to my innate fighting style. This instinct would probably serve me well in a street fight. But you can’t spar that way, or you’d piss people off pretty fast. My sister still doesn’t trust me around sharp objects.

Tonight, like most nights, I jam people’s kicks and trap their punches and then apologize repeatedly for these transgressions (apologizing is also a no-no). I get hit, kicked, and winded. I see all my mistakes in slow motion. My sparring gear smells dreadful because I forgot to air it out last week, and my mouthpiece is shredding my gums. And I suspect my shin guards make my butt look big.

But sparring isn’t only about me. It’s just as much about my partners. Tonight I spar with a black belt who has Multiple Sclerosis but kicks like a coal-pit mule. I know she punches hard too, but I rarely get close enough to find out.

I spar with a fellow mother of two, who will test for her black belt next spring. When she first started sparring a couple of years ago she was very tentative. She’s not anymore.

I spar with a former offensive linesman in the Women’s Professional Football League who laughs delightedly whenever she hits me or I hit her. It’s like fighting a very jolly grizzly bear, and though I will be feeling it tomorrow, I have a blast.

Each partner adds a little more solidity to my idea of an opponent. Each one teaches me something. Each one of them will be with me for a long, long time.

And once in a while I block something. Once in a while I land something. It’s all good, and these people beating me up are doing a beautiful job. It’s a pleasure to see them work. I’m dripping with sweat but I feel utterly clean. And I see the yellow and blue belts waiting for the next class, watching us. They can’t wait until they are advanced enough to start sparring. And it’s pretty damned sweet.