Are you too old (fat, out of shape, handicapped, untalented) for karate?

I actively read a large number of martial arts related forums, mostly because I have a social media problem and not because there's a ton of value in their contents (though I do find some gems). I frequently see questions that look like this:

"I'm (old or fat or out of shape or handicapped in some way). Is it worth starting karate (or some other martial art)?"

Now my strong suspicion is that this isn't a real question - the person knows that it's okay to start karate, no matter how old or fat they are, but they want some encouragement and positive feedback. And that's fine, I have no problem with people using social media to get some metaphorical massaging from strangers.

But the real answer is twofold:

1. Of course it is. Literally no matter who you are (maybe other than an actual quadriplegic), you can train in martial arts - and if you do, you'll soon be much, much better than you are now!

2. Probably not. No matter how hard you train, you'll never be as skilled as a truly gifted athlete who has been training since youth. You literally will never catch up to them and be as skilled as they are!

Which one is the real answer? Both. Because the question is ambiguous.

If you are only willing to start martial arts training if you have a reasonable chance of being one of the best in the world at it, then yes, you're probably too fat, too old, too out of shape, and too un-talented to start.

BUT if you want to study martial arts because you're interested in the myriad benefits of martial arts training (better physical health and fitness, improved self confidence, better mental health, improved capacity for self defense) then, unless you're a quadriplegic (sorry to quadriplegics), you can absolutely gain those things.

If you want to be better at martial arts than other martial artists who have been training since childhood, your chances are slim. If you want to be better than the general population, your chance is almost 100%.

The 'trick' to being happy with your training is recognizing what you want, and to whom you should compare yourself, and realizing what your expectations should be.

I will never be able to win a UFC match. I would absolutely win a MMA fight against 90% of my peers (meaning, men of my size in my age category) - because most of my peer have absolutely no training. Compared to my peers who train in martial arts I am probably below average (I've taken long breaks from training). Maybe I'm average? I'm not really sure.

BUT I guarantee that I'm much, much better at martial arts, and more fit, and healthier, than an alternate version of myself who didn't train at all.

So the real secret to success in martial arts is in carefully choosing how you evaluate your success! If you only think you're 'good' if you're holding a UFC belt (or have won an Olympic medal or an international tournament) then you'll most likely never be happy. If you are happy knowing you're better than you would have been without training, then you're guaranteed to benefit from training.

Osu.

Bollywood Martial Arts films

I love Bollywood movies.

I barely remember how I got hooked - I'm pretty sure I started with Krrish, which I watched because it's a superhero flick and I was curious (quick review: it's fine, not great). Then Netflix offered up Baahubali, which is an amazing 2 part movie that everyone should see (though it's a Tollywood movie, meaning it was shot in Tamil and Telugu, not really Bollywood). From there somehow I got addicted to standard Bollywood movies, especially those from a golden age from 1997-2012, and especially romantic comedies. Ironically, my wife is South Asian, and I've introduced her to these films (if you didn't know, I'm an American Jew of Eastern European descent and I have no real connection to South Asian culture other than a love of spicy food and the fact that I recently married into a South Asian family).

So if I criticize Indian movies, I'm coming from a place of love. My favorite actor is Shah Rukh Khan; my favorite actress is Kajol; I love Bollywood and watch Indian movies all the time. I'm not a hater on Indian movies.

But most Bollywood action movies have terrible martial arts.

[Small caveat: I'm not really in a position to comment on Indian cinema as a whole. India produces a ridiculous number of movies each year, and other than 50 words in Hindi I don't speak any South Asian languages. So I'm really only commenting on the Indian movies that are available in the US, on Netflix or Amazon Prime, with English subtitles. If you're reading this and can speak to other Indian movies with great martial arts, please comment on this post!]

I mean this in two ways. If you watch a standard Indian action movie, like the Dhoom or Race series, when and if there are unarmed combat scenes, they're pretty mediocre compared to similar Hollywood movies. The Bourne series, for example, has much better fight scenes.

Also, there are relatively few Indian movies with a real martial arts focus (or, as I mentioned above, they aren't getting subtitled and/or aren't available for streaming here).

The closest thing India has to a martial arts focused actor is Tiger Shroff (son of famous actor Jackie Shroff). Tiger (not his real name) seems to have some legit martial arts background in tae kwon do. He has 3 films you can watch in the US, in English (all have been on Netflix):
1. Heropanti - very entertaining - I found Tiger super charming is this one. B- for the martial arts (not bad, but nothing super innovative or exciting. This is no Ong Bak).
2. A Flying Jatt - superhero movie, also quite fun, maybe C+ as a martial arts film, but B- as a movie.
3. Baaghi - straight up martial arts standard movie plot and style. B+ as a martial arts movie, but nowhere near in the can't-miss level of something like Ong Bak or The Raid.


Other Indian martial arts films that you can find on Netflix or Amazon Prime:

Waarrior Savitri: retelling of a famous Indian fable in the modern day, using martial arts. Not a terrible movie, but not a good martial arts movie. Maybe C- as a martial arts film.

Kung Fu Yoga: Might be Jackie Chan's worst movie. Avoid at all costs.

Mard Ko Dard Nahi Hota: This is the gem. On Netflix now, this is both a pretty entertaining movie (nice plot, funny moments, good acting, everything you'd want in a good movie, B+ as a general film) it also has some excellent martial arts. Ironically, the best moves are probably done by the female costar, who has some really lovely scenes using a scar as a weapon.
Watch this one! B+ (maybe even an A-) as a martial arts film!!!

Generally speaking, martial arts haven't penetrated India's entertainment industry the way they have in, say, Thailand.

If you haven't watched any Bollywood and are looking for a primer, that's something I might do at some point. Watch Kal Ho Na Ho - if you don't love that film, give up (also, what is wrong with you???)

Please comment if you think I've missed anything!

Osu.

Karate for Fat Bastards

[Please note that I'm  using the term "Fat Bastards" in the most affectionate tone possible. And also note that I count myself as absolutely a member of that group!]

What's a Fat Bastard? For the sake of this post, I'm talking about anybody who is thickly built. Stocky, big boned, actually fat, or even lean but with a lot of muscle. Anybody who couldn't be called lanky. And I don't mean to exclude women, but the term 'Fat Bitch" doesn't have the same playful connotation (at least in American English), so I'm going to avoid it.

Why am I writing about thickly built people? Because in many ways karate is designed to favor the lanky, the scrawny, the width challenged individual. Karate is easier for skinny people.

Now you're probably thinking, "Surely this is overstating things, Joe?" No, it's not. It starts even before the class begins, as soon as you put on a gi. Why do we wear a jacket that wraps a double layer around our midsection? Who looks good in this? Only skinny people. If you are already wide through the torso, a gi just makes you look fatter and blockier. If you're very skinny, it gives some substance.

Second: point fighting. Point fighting is combat designed to strip away all the advantages of solidity and mass. In a full contact fight, solidly built people have some advantages - being able to absorb bigger impacts without falling, generally being able to hit harder. Point fighting is made to take away those advantages and make frail, skinny people look more effective than they are. Don't agree? Find someone your height but 25 kg heavier and similarly skilled to you. Stand toe to toe and trade full contact left hooks to the body with them. Then do 2 rounds of point fighting. See who 'wins' each phase.

Third: jumping techniques. I promise you the first person who decided to try a spinning jumping kick did not weigh over 100 kg. How good you are at getting into the air has a lot to do with different kinds of strength, but weighing more is always going to make it harder.

What should the thickly build karateka do? Well, if you're carrying a lot of extra fat, you should probably try to get rid of some of it, for health reasons (remember, having extra fat isn't particularly healthy, but neither are some of the methods people use to lose fat, so be sensible. If you can safely remove some fat, great, but don't starve to death or shoot your stress levels through the roof to get skinnier). At some point, though, many of us will have realize that even with reasonable efforts in that direction we're still thickly built; either big boned or heavily muscled or carrying stubborn fat or some combination of those.

My first instinct is to tell the thickly built karateka to sort of focus on the aspects of karate that work well for the thick and focus less on those that don't. For example, focus on clean technique, rooted stances, fighting from up close and with greater contact. Worry less about anything with jumping and spinning. Work to break lots of boards in a stack, and not to break a board flipped up into the air with some kind of jumping technique. Get really strong. Make sure you are training a style that does some contact!

But the more I thought about it the less I liked this answer.

The truth is this: If you're thick, you're at a disadvantage developing those kinds of skills (jumping, spinning, speed-based stuff). You'll probably never be truly elite in those areas. But if you really love that stuff, you can also definitely get much, much better at them than you are now.

So if you love that type of karate, you have a decision to make: either focus on those skills knowing that you'll never be quite as good at them as people who are better suited to them (and also work hard) OR shift your attention to the type of karate that your body is 'designed' for.

And really, neither answer is wrong.

I personally know that I would find focusing on skills that don't suit my body too demoralizing - for me. I personally couldn't sustain that kind of martial arts practice over a lifetime. I, instead, focus on being able to hit the heavy bag as hard as possible, and focus on strategies in kumite that get my opponents closer to me. I'll never be truly elite at anything in martial arts, but I can be pretty good at those sort of things.

But if I loved the jumping stuff enough, I'm sure I could work on it and get much better at it than I am now, even if I could never be great.

And the more I think about this, the more I feel it's true for other types of limitations.

If your'e genetically suited for endurance rather than speed, you'll never be a great sprinter. So if you're trying to compete in the Olympics, you'd better train for marathons and not the 100m. But if you're just a recreational runner who loves sprints, and you can handle the idea of working on sprints your whole life without ever becoming really great at sprinting, then go for it! But go for it with open eyes.

Find a way to train that YOU will love, then do it. There is no right or wrong beyond that.

What to Watch Jan 2019

I've posted about this before, but it bears repeating: if you love martial arts you might love martial arts based entertainment. For many, watching martial arts movies and tv shows, realist or not, can be highly motivational and fun.

I know many experienced martial artists have little to no patience for highly unrealistic martial arts based entertainment - I'm not one of them. I can appreciate a crazy ridiculous movie or cartoon as much as a hyper realistic fight scene (maybe more).

Most of what I watch on TV is not martial arts or action - most of what I personally watch is Bollywood movies (no, I'm not Indian, and no, my South Asian wife is not into Bollywood, I came by this addiction all on my own). I'm not going to go on and on about why I love Bollywood here, but to be honest Bollywood movies rarely have well executed fight scenes, so from a martial arts perspective I wouldn't recommend them, even the action oriented films. (If you are interested in Bollywood, by all means go on Netflix and search for Shah Rukh Khan, the greatest actor who has ever lived, and watch anything of his - start with Happy New Year. If you have Amazon Prime, watch Kal Ho Naa Ho, then Khabi Khushi Khabie Gham, then DM me for more recommendations once you've stopped crying).

I'm going to put in here a few very short reviews about things I've been watching that are martial arts based. Everything I put in is on Netflix in the US (sorry, I'm not sure what Netflix has if you're in another country, and I'm not sure how to check - if anybody feels like adding recommendations from other country's options in the comments please feel free).

Iron Fist (TV show, Marvel universe, 2 seasons)
This was bad in every way. The fight scenes were pretty bad - though season 2 had a couple of well done scenes. See if you can find the Misty Knight/ Colleen Wing fight scenes on Netflix or google their locations in the series. Don't just watch it straight through, unless you're a masochist.

Daredevil (TV show, Marvel universe, 3 seasons)
Seasons 1 and 3 were outstanding and season 2 was very good (ironically, season 2 had more ninjas, yet wasn't as good as the others). Great acting, stellar storylines, and fantastic fight scenes - but these were not action packed. It's not one of those things where there's 5 minutes of fighting, 1 minute of dialogue, then 5 minutes of fighting, so if you're looking for sort of mindless action, this isn't for you (watch the Raid, below).

The Night Comes For Us (Movie, Iko Uwais)
Outstanding in every way. All action, all the way through. I love Iko Uwais movies - He's a great performer, first of all, but I find the films he's in (and this might have nothing to do with him) fun because they're less gut wrenching (usually) then Tony Jaa films. With a Tony Jaa film I feel like I'm always sitting through an hour of an elephant being tortured before the action starts. I'm very sensitive, I hate that stuff. With Iko's movies you're usually invested in the characters right away without having to watch the 'bad' guys do a whole lot of terrible things so you feel better when the revenge happens.
Iko's moves are silat based and look fantastic. He's NOT the main character in this movie, but it's amazing anyway. NOTE: kind of gory, lots of blood and shattered bones. Not good for kids.

The Raid: Redemption (Movie, Iko Uwais)
Amazing. Watch it. Also gory and maybe not for kids. All action all the way through.

The Final Master (Movie, Chinese)
Really, really good film. Great story, actual character development, fantastic fight scenes (all wing chun-ish). Absolutely watch it.

Rise of the Legend (Movie, Chinese)
Really good action film. Watch it.

Beyond Skyline (Movie, sci-fi, costars Iko Uwais)
Meh. Miss it. It's fine for a B level sci fi film, but not actually good, and the fight scenes alone aren't worth the rest of the film.

Baaghi (Movie, Tiger Schroff, Bollywood)
The only Bollywood title on this list. Greatest Indian martial arts movie ever made. Not bad, but not great. Action scenes are reminiscent of Jean Claude Van Dam films - Tiger Schroff is pretty athletic - but not up to 2018 international standards. Of course, it has the best music and dancing of any movie on this list. Another good Tiger Schroff is Heropanti - very, very amusing (and no, it has nothing to do with panties).

Broken Sword Hero (Movie, Buakaw, Thai)
Not terrible, I guess? I have a soft spot for Buakaw, who is an amazing and entertaining kickboxer in real life (not an actor). Above average action, decent story, acting is fine. Watch if you have time.

Sword of Destiny (Movie, Chinese, sequel to Crouching Tiger, Hidden Dragon)
Not terrible, but it's no Crouching Tiger. It's fine. Miss if you're busy.

The Last Dragon (Movie, American)
I can't objectively evaluate this movie. It's a cult favorite of mine, and as such holds a very, very special place in my soul. Watch it, because even if it's not a great film, it's a cultural milestone.

Mugamoodi (Movie, Tamil)
Weird super hero (but relatively realistic)/romance thing going on. Tamil films are very similar to Bollywood (but not the same) in tone, and this is no exception, so don't be surprised by the dance numbers and casual racism. Still, pretty decent action scenes and storyline (but not good).

Man of Tai Chi (Movie, Keanu Reeves!)
Super talented tai chi student fights in tournaments to prove the efficacy of his art, getting ever more brutal and advanced as he goes, until he's in kill or be killed fights with crazy Keanu Reeves. Absolutely worth watching.

There are more. I'm making my way through Monkey Twins right now, so far... it's fine, but not good.

Osu!

Fasting: 5 questions answered

I posted recently about intermittent fasting for karate practitioners. If you don't want to read it, I'll summarize: I believe fasting (going for periods from 16 hours and up without eating anything, though probably no more than 72 hours at a time) is a great way to control bodyfat, insulin sensitivity, and might provide some other intriguing health benefits with very few risks. It might also improve sports performance (by facilitating fat adaption) and muscle mass and strength (which is counterintuitive).

I'm on a few fasting related message boards and a few things come up repeatedly as people ask about IF. Here's a summary of answers:

1. Can I fast if I'm diabetic?
MAYBE but NOT UNSUPERVISED. I can't stress this enough.
If your'e on diabetes medications you can't just suddenly decide to skip meals or entire days of meals without changing your meds. Diabetes medications are designed to reduce blood sugar. The dose you're on should be well calibrated to your current body and diet. If you suddenly change your diet, those meds might not work anymore. You can't expect your blood sugar to end up in a good place if you suddenly stop eating any more than you'd expect it to stay low if you suddenly started eating a sheet cake with every meal.
The real danger is that if you started eating an entire sheet cake with every meal your sugar would go UP, and that's less acutely dangerous (i.e. having very high blood sugar this very minute won't kill you this very minute, even if it's doing long term damage). Having very low blood sugar actually can make you pass out or die.
So fasting might be a great and healthy thing to do if you're diabetic, BUT you have to carefully monitor your blood glucose and adjust your medications to match as you do it. DO NOT try this alone.

2. Will consuming break the fast?
I see this question constantly - "I like to have a hard boiled egg in the morning, does that break the fast?" "Will coffee with cream break the fast?" And so on.
The answer to this is a little layered.
First of all, it isn't completely proven that fasting provides benefits beyond the caloric restriction that comes with it. It's not conclusive that a 20/4 eating plan that gives you 2000 kCal/day is better in any way than a spread out plan where you consume the exact same quantity of food over the whole day.
But I strongly suspect that the 20/4 is better. If you disagree, then you shouldn't care about breaking the fast because you don't think the fast is doing anything useful.
We still don't know exactly what it is about fasting that provides these additional benefits. So we can't say with real certainty what 'breaks the fast' because we don't know exactly what 'the fast' means from a physiological perspective.
Water probably doesn't 'break the fast' because nobody really thinks that dehydration has anything to do with the benefits of fasting. So plain water definitely doesn't break the fast.
Non-caloric, no-taste nutrients probably don't break the fast. I mean things like caffeine pills, vitamins and minerals, and electrolytes. I have never seen an idea for 'how fasts work' that would be broken by taking some electrolytes or Vitamin D, for example.
Small or large amounts of dietary fat by itself almost definitely doesn't break the fast. So you can add cream to your black coffee. Why am I so sure of this? Because while fasting your body can dump tons of fat into your blood, from your own bodyfat, anytime. And it does. If having fat in your blood 'broke the fast' nobody would ever be able to fast, at least not while alive.

Non-caloric non-sweetener flavorings probably don't break the fast. Think flavored water type beverages that aren't sweet, or black coffee, or unsweetened tea. These things might impact insulin, which might 'break' the fast's benefits, but I doubt it. Future science might prove this wrong.

Non-caloric sweeteners are a really tough call. They might increase insulin, which might 'break the fast' in terms of halting the benefits of fasting. But if you take them regularly, that effect might go away, and in real terms it's terribly unclear how much insulin you'd need to release to have an important physiological effect. So... I'm not sure. If you are absolutely committed to fasting, play it safe and skip the diet sodas. If you just can't manage without them... I sympathize, but I honestly can't tell you how bad it is (and nobody else can, either).
Protein or carbohydrates in small amounts either don't break the fast or only set it back a little. What do I mean by 'small amount?' Imagine eating a single peanut. It's possible that could knock you out of a fasting state, but for how long? A few minutes?
The problem comes when people extend this logic to encompass larger portions of protein and carbohydrate foods. What if you ate a peanut every 2 minutes all day long? I bet that would negate the fast. Or the hard boiled egg I mentioned above (that was taken from a real question on a fasting support forum). Nobody can really answer how detrimental a single egg can be - does it negate an hours worth of fasting? Half an hour? Two hours? Nobody knows.
Foods with lots of protein and/or carbohydrates will definitely break the fast. That's literally what breakfast is.

3. I'm having . Is it okay to skip my fast or break it early?
Good grief, yes.

4. What about fasting and detoxification?
OMG please stop with the detox.
"Detox" as it's used in popular diet talk is meaningless. If anybody talks about a 'detox diet,' ask them to specify what toxins are being removed from your body and by what biological process.
If they answer (they won't), post it to comments and we can look into whether skipping a few meals can interfere with that process.
Any kind of caloric restriction can reduce inflammation, which can help with a whole host of chronic conditions. That doesn't mean you're 'removing toxins from your body.'

5. Can I exercise while fasting?
Yes, you can do any exercise while fasting that you could do while fed. Your performance will probably suffer, though, especially if you're combining fasting with a low carbohydrate approach (which is popular but not what I personally recommend). You will, in my experience, find that the more you exercise while fasted the easier it gets. Either way, it's not dangerous or harmful to try.


I'm not a fasting evangelist. I'm not an anything-evangelist. My goal is never to tell you the absolute best way to do anything, because I am never certain that I know the best way to do anything. I do try to honestly give you the best advice I can, distilled from the best advice popularly available today, based on the best scientific evidence and reasoning that we have available. New studies could turn up tomorrow that force us to rethink some of these ideas, and when I find out about them, I'll post it here.
Osu.

Go Half In: train like you kinda-sorta mean it!

This post is all about do what I say, not what I do.

I was listening to a podcast interview with a chiropractor (sorry, forgot his name, but it's not super relevant to this post) who is a fan of Tony Robbins (the self help 'guru,' and I don't mean that to be disparaging). He met Tony in an elevator before a seminar and asked what he could do to get the most out of it, and Tony said (I'm paraphrasing) he needed to go "all in." Basically, completely immerse himself in the content for the duration - do every exercise, take every suggestion, fully commit to the program for those three days without reservations.

We probably all understand this notion in terms of martial arts training. Going all in with your training means taking every class, stretching and practicing on your off days, eating sensibly, getting enough sleep, maybe doing extra conditioning or strength training sessions on your own time. And if you aren't the person who does that, I'm sure you know people who do - the most gung ho, most enthusiastic practitioners. Usually, they're young enough not to have outside responsibilities, or beginners. But some people maintain that level of training for longer.

For people who aren't always "all in," they often go all in for certain periods of time. Think of the months leading up to a big tournament or black belt promotion. Fear and the desire to perform often lead us to work extra hard in those times. In the 3 months before my shodan test I think I trained 12-14 hours a week.

The thing is, karate is a lifetime discipline, but most people can't go all in for a lifetime.

Maybe right now you're thinking of counterexamples - people who train maniacally for their entire lives. That's fantastic for them. If someone has a lifestyle that lets them do that, and is able to maintain that level of enthusiasm, that's great. For them. But for most of us regular people with jobs, relationships, kids, fluctuating health and injury status, and fluctuating life circumstances, going all in all the time is just not possible.

And here's the thing: we celebrate the people who train extra hard, never miss a class, are in great shape all the time, never fall off the wagon. (We should celebrate that, I'm not against it).

What's the problem with that? Where's the issue?

The problem, as I see it, is when we think that "all in" is the only way to train (or the only way to progress), and that's simply not true.

I figured out my personal definition of "all in." When I train 5+ hours a week spread out over at least 4 workouts (that combines actual classes with supplementary workouts) I feel like I'm really going all in. I've done more, that's not an upper limit, but that's the time commitment that makes me feel like I'm really dedicated to training.

Over and over again, in my own life, when I've found myself unable to get those 5+ hours a week in, for whatever reason, I get extremely discouraged. I feel like a hypocrite wearing a black belt to class. I feel that I don't deserve respect that is given to me by others in the training hall. I feel as though I've betrayed my art, my teachers, and my style (Seido Karate).

And it's very, very hard for me to get over those feelings - to the point where I stop training altogether. If I can't go "all in," then I go "all out." Meaning I stop training, or at least stop going to classes.

While I started training 30 years ago, I've only trained consistently for 10-12 years out of that time (not 10-12 years straight; I mean spread out over many stretches with breaks in between). I'm only a third degree black belt.

And I guarantee this - if every time I couldn't fully commit to training, I had, instead of stopping altogether, put in 1-2 hours a week of training, I would be a much, much stronger karateka than I am now.

I'm not saying I'd be as good as another person who trained "all in" for 30 years. I'm simply saying that if I had put in 1-2 hours a week for those approximately 18 years when I didn't train, I would have accumulated another thousand hours of training time. And I'm sure my training would have been more efficient - once you learn a kata, if you do it every week or two you never forget it, while trust me after you take two years off you have to relearn it almost from scratch.

Summary: Don't be afraid of backing off from training; be afraid of not training! You don't have to attend every class, train every day, or be the hardest worker around in order to make progress and improve your karate. Don't feel bad for taking it easy when you have to. "All in" training is great, but "half in" is much, much better than "all out." And if you have stretches of time where things are a little easier, where your kids are a little older and not as needy, when your job is going okay, your marriage is okay, and you have a little extra time and energy, train all in! Enjoy it.

Keto and Karate: A Good Fit?

Ketogenic Diets are very popular right now, for reasons I'm not entirely clear about. I've played with ketogenic diets on and off for the past 10+ years, and read a lot of the literature around them, so I figured it was time to talk a little about how useful they are for karateka.

What is Ketosis?
It's easier to start with a brief overview of 'normal' (I really mean typical) metabolism.
Your body needs energy all the time, in every living cell. Most of that energy comes from glucose or from fat. Your body stores both - there is glucose stored in the form of glycogen in your muscles and liver, and fat stored all over the place. When you need energy somewhere it gets glucose and/or fat from the blood and uses it for energy. When the glucose or fat in the blood get too low, more is moved from storage into the blood.
The glucose mostly comes from food (carbohydrates), but your body can make some glucose from proteins and fats (through a process called gluconeogenesis).
Some types of cells are better at using fat, others are better at using glucose. To some extent you can improve your body's ability to use either fat or glucose by eating and training in a certain way, but there are limits (you can never get your brain to run on fat).
If your cells aren't able to get enough glucose (this can happen either because you've run low on glucose OR because it can't get into the cells, as in with a Type I diabetic), your body will start making ketones out of fat. Ketones are just another molecule that your cells can use for energy. Some cells that are bad at using fat directly (like neurons) can use ketones, so you can stay alive even when glucose is in short supply. 'Normally' you make very few or no ketones.
Nutritional Ketosis is what happens when you restrict your carbohydrate intake (don't eat any) and protein intake for a while (specifics aren't important here, but 'a while' means days or weeks, not minutes or hours). At first, your body will just use stored glucose (glycogen) to fulfill its needs, but if that glycogen gets used faster than it's replenished, eventually it runs out (or at least runs very low). Then you start making ketones really quickly, to fulfill your energy needs.
Diabetics can get into ketosis while their insulin and blood sugars are both high. This is a different state and can be very dangerous. Diabetic Ketoacidosis and Nutritional Ketosis are not the same thing.
To be even more clear: on a 'normal' or typical diet, you will have very small amounts of ketones in your blood. If you eat certain foods (Medium Chain Triglycerides, as found in coconut oil) OR deplete your body's stores of carbohydrates enough, your body will start making lots of them.

What's are the benefits of being in ketosis?
There's a lot to unpack here - as with fasting, a lot of the science is mixed.
Health/Body Composition Benefits:
Being on a ketogenic diet (nutritional ketosis - very low carb, not high protein, high fat diets) might facilitate bodyfat loss. This is contentious - there are lots of reputable people who think that ketogenic diets are great for weight loss and others who disagree. I'm not going to take a stand - do the research yourself. I personally suspect that ketogenic diets are better for fat loss but hard to sustain compared to some other successful eating plans.
Having high levels of ketones in your bloodstream might have other benefits. Because ketones can provide cells with energy but get into the cells in a way that's different from glucose, they might help feed cells that are insulin resistant. This is especially interesting with the brain. There is pretty strong evidence that having ketones in the blood can help the brain resist traumatic injury and help the brain recover from injuries. Some also believe that high levels of ketones can prevent symptoms of Alzheimer's and dementia (I'm not going to say this is definitely true; I will say that I suspect the idea has a lot of merit).
There are a lot of other claims made about ketogenic diets, more than I have space to discuss here. Dig around if you're interested.
Performance Benefits:
This is another controversial area.
Your body can use ketones for energy. Your body can also make an effectively infinite amount of them. Suppose you want to run 100 miles. Your body can't store anywhere near enough glycogen to fuel that sort of effort - you'd need to eat carbohydrates along the way, and lots of them, to make it that far. But almost everyone has more than enough energy stored as fat to run 100 miles (it's not even close). So, in theory, if you could get all your energy for the run from ketones, you wouldn't have to slam down carbohydrate gels or eat along the way.
However, power is limited on ketones. You can generate energy forever (practically) using ketones, but you can't generate it very quickly. Yes, you can run 100 miles on ketones, but you won't run any of those miles at anywhere close to your maximum speed.
Having ketones and glucose in your system at the same time hasn't been well studied to my knowledge. It should provide performance benefits without any disadvantages, but it's not easy to get into that state.

So should karateka be on a ketogenic diet?
Short answer: no.
To actually get into ketosis you have to be on a very low carbohydrate diet until your body's stored glucose is very, very low. In other words, you can't have anywhere close to full glycogen levels. If you have lots of glycogen, you won't be in ketosis.
And there is abundant evidence that your body won't be able to generate high levels of power without lots of glycogen around. This makes sense - if you look at the energy systems, the glycolitic system runs on glucose. If you have no glucose around, and really deplete ATP levels, you'll crash, and the energy systems that can use fat or ketones to regenerate ATP from ADP won't be able to keep up with demand. So your body limits power output to prevent a crash.
So if you're in nutritional ketosis, your punches will lack snap, your speed will be limited - basically, you'll be a slower, less explosive version of yourself.
Some people think you can become 'fat adapted' and avoid this fate. Not true. Yes, if you exercise a lot while glycogen levels are low you can get better at using fat (or ketones) for energy, you'll never magically be able to generate peak power off of ketones.
This isn't even really controversial. Without glycogen your body is like a racecar without its highest gears. You can work hard, and for a long time, but you lose that top end speed. No amount of practice or training will completely change that.

HOWEVER:
I want to provide 2 caveats:

1. For you, it's possible that the health benefits of a ketogenic diet are more important than your karate performance. This is something you'll have to figure out for yourself. As a corollary to this, you might find benefits to being in a ketogenic diet in a periodized way - say, 1 month a year, or a couple of weeks at a time, every so often. That's fine, just be aware that your karate will suffer during those times.
2. The reduction in power output ISN'T CAUSED BY THE KETONES BUT BY THE LACK OF GLYCOGEN. So what, you ask? It is quite possible that you could get the benefits of nutritional ketosis without the downsides - by eating ketones. There are supplements out there that are just pills full of ketones. In other words, instead of getting high levels of ketones in your blood by depleting carbohydrates until your body 'thinks' it's starving, just consume ketones and let them get absorbed. This approach is relatively new - the supplements are expensive - and may or may not work. If it does, you'd potentially have a little extra endurance when you work out. Also, more interestingly, you might have some protection against head trauma. Another approach is to eat a lot of MCT (medium chain triglycerides) either in coconut oil or in a dedicated supplement. Your body turns MCT into ketones almost directly, so if you can consume enough of it you can get elevated ketones in your blood without depleting glycogen.

If I were, say, a professional fighter, I would absolutely load up on ketone supplements before hard sparring sessions or fights. We have very little reason to think it could make anything worse (performance or health) and some reasonably strong reasons that it could protect our brains. The downside is that the supplements are expensive. If you have money to burn, go ahead and try them! But nutritional ketosis is not conducive to martial arts training at any level, so I don't recommend it.