I have to admit that I have some envy toward people who train athletes for competitive sports. In most cases, sports entail some kind of event, with fairly specific and easily measurable physical demands. In light of those demands it's relatively easy to develop a training program to prepare an athlete.
Take a sprinter - say, someone who runs the 100m sprint. What kind of training do they need? It's fairly simple - they need to train to be faster at running 100m. And, to be honest, they have a pretty good idea of how many times in a day or weekend they'd have to run it. Nobody is asking these guys to run 100m fast every 5 minutes for a few hours. If you're a sprint coach, you have a very good idea how many races would be asked for, with how much rest, and how many repetitions per day.
Some sports are more complicated. I know that the energy demands of, say, high level soccer are at least slightly controversial, but modern coaches have strapped gps devices to their athletes and have a really good idea of how much running their athletes have to do, at what intensities, with how much rest, and over what period of time.
American football is another interesting example. The demands vary by position. Offensive lineman don't do the same things as wide receivers. But it doesn't take a rocket scientist to figure out what players at each position have to be able to do, and it's not terribly hard to design a training program to enhance those qualities.
[Quick note; there will always be controversy and change in the details of these programs, I'm not pretending that every strength and conditioning coach does exactly the same things. I'm merely pointing out that the training for offensive lineman will be roughly similar to the way any other offensive lineman changes, and drastically different from the way the team's wide receiver trains, and even more different, in predictable ways, from the way someone preparing to run a marathon would train.]
When training a soccer player, you have to prepare them for the demands of a soccer game (or match or whatever they call it). Training a UFC fighter, you'd have to prepare them for some combination of striking and grappling spread out over a series of five minute rounds. Training a kickboxer requires preparing an athlete to spar for three minute rounds, with no grappling at all. Figuring out the specifics for each training scenario isn't always easy, but the goal is fairly clear.
What, then, is the equivalent training goal for the karateka? What's our event?
There is no obvious single answer. There is no single physical event that is to the karateka what a football game is to a football player.
For sport karate, where you train primarily to compete in organized events, be it kumite, kata, or tameshiwari, I imagine things are simpler. In those cases you can pick your event(s) and figure out what your body needs to be able to do.
But what about those of us who aren't particularly interested in competition? How should we train?
My early inclination was to say that a karateka should train for a streetfight, or for a self defense scenario. From my understanding, most 'real' (not sport) fights are fairly quick and fairly intense. Proper training for a situation like that would be primarily anaerobic, probably anaerobic alactic (i.e. very short bursts of energy), a lot more like an Olympic weightlifter or a powerlifter or a 100 m sprinter than like an mma fighter.
After all, if you're in a real, honest to goodness fight, would you rather be the guy who is faster, stronger, more explosive, yet out of breath after a few minutes, or the guy who is weaker and slower but can continue for hours? Endurance doesn't do you much good when you're knocked unconscious in the first 10 seconds of a fight, and all the evidence says that 'real' fights almost never last much longer than that. Five minute long knock down, drag out fights happen in movies or in rings, not in the street.
The problem with this way of thinking (and, I have to admit, this was MY way of thinking for a long time), is that it overlooks the central component of karate training: skill acquisition.
The entire point of karate is not to simply become stronger and more explosive as a way to handle self defense situations. The point of karate, in fact the very essence of karate, is to develop a set of skills to handle a self defense or combat situation as effectively as possible.
Nobody who just lifts weights and does pushups and pistols (one legged squats) without ever practicing punches, kicks, blocks, and movement would call themselves a karateka. The 'karate' part isn't the pushups, its the skills you learn - the technique, the timing, and the applications of those techniques. I mean, you might disagree with another karate style about which techniques are best, or the proper way to execute them, but I have never heard of a karate dojo that skipped all technique practice completely.
How does one develop that set of advanced skills that make up karate? There we get to the core problem with training for a fight: learning the skills that it takes to fight requires many hours of practice. From a motor learning perspective we know that this practice must happen when the nervous system and muscular system is relatively free of fatigue (you can't get better at skills when you're quivering and drained). So if you're tired after five minutes of skills practice, the rest of your practice time is largely wasted.
So how do we get the hundreds or thousands of hours of practice needed to master the skillset that makes up karate? In an ideal world perhaps we could train in short bursts, many times a day, to match the demands of an actual fight. But that's wildly impractical for pretty much everybody.
In reality, we all have to train in longer stretches. Depending on your school your classes might be one or two hours long, and while some of that is lower intensity work, some substantial portion of it is going to be pretty intense.
If we train just to withstand the metabolic demands of a streetfight, and no more than that, we won't be adequately prepared to withstand the demands of the training that we need to do to learn the skills we need to survive a streetfight.
I can be slightly more specific: Train to meet the metabolic and physical demands of your class or your training session.
If your instructor makes you do 200 pushups and 200 squat kicks at the start of every class, you'd better be able to knock those out without being so exhausted and winded that you're not fresh for the skills practice that comes afterwards (which, by the way, is why starting class with 200 pushups and 200 squat kicks is probably a bad move, but that's a different blog post).
If you're an anaerobic alactic powerhouse, capable of enormous force output and amazingly explosive for about 12 seconds before gassing out, you might be physically prepared for a fight but you'll never be able to survive learning the skills it takes to be a karateka.
So when you do your strength and conditioning program design, your first goal should be to build the general physical preparedness it takes to survive your karate training sessions with enough in the tank to get good motor learning of the techniques. Only once you're fit enough to handle the training sessions should you progress to increasing your ability to function in actual combat situations.
But above all else, the best program is the one you'll actually do, so make sure to pick exercises that you enjoy and that motivate you. If you like being jacked, build some muscle. If you like going all day without being tired, add endurance work.