I am sometimes asked to cover a specific topic on this blog. In this case, Lisa Jenkins, from the Minnesota Sword Club sent me this question:

I was wondering if you would share a blog post on practical things like sports nutrition for hema, and ways to keep cool and hydrated while exercising underneath a lot of protective gear (our club has no air conditioning.)  I’d be curious to hear what you have to say about these aspects of training.  I read in your Swordsman’s Companion book that you run a school that treats students holistically—I’d be very interested in getting an idea of what you include in your system.

Nutrition is a huge and knotty subject, so let’s deal with hydration and keeping cool first.

If you are training in hot conditions, drink plenty of water; my key indicator for this is bathroom breaks. There’s a saying I learned living in the tropics; if you don’t need to pee, you’re dehydrated. If drinking water doesn’t help, and especially if you are feeling dizzy but have been keeping your fluids up, then check your salt intake. I do this by mixing a teaspoon of table salt with just enough water to dissolve most of it, and taste it. If it tastes horrible, you shouldn’t drink it; if it tastes wonderful, you’re probably salt depleted and should drink it down, followed by a glass of water.

Given that it is only hot in Finland for about ten minutes per year (well, this summer about two months), we could schedule most full-kit training to more temperate times of year. (We don't.) But in case that’s not an option, then overheating in kit, like anything else, can be trained for. Gradually and systematically build up your tolerance for overheating, the way you would gradually and systematically build up your push-ups.

Above all, know when to stop. A few years ago I held the field at WMAW, against all comers with any weapon, in a swelteringly hot gym. It was great fun, but after an hour or so, while I was hot and getting tired, I shivered. A full-body shudder, like I was soaking wet on a freezing Scottish hillside in winter. So I had just one more bout, and stopped. (As a responsible instructor, I should have stopped immediately. But there was a queue of people waiting to fight me, and I couldn’t bear to let them all down.)

Now for nutrition. Here are some key ideas.

Food is personal

Food is one of those topics that entire lifestyles can revolve around. It is a critical part of every culture; there are no culturally-neutral cuisines. Foods also tend to have deeply personal associations. My grandma’s cherry pie is, I’m sorry to have to break this to you, way better than yours. Roast turkey with all the trimmings, but at Easter not Christmas? That would be weird, right? My brother-in-law is Jewish, and my sister-in-law is Muslim, so neither are likely to be found scoffing bacon, and so on.

Just because a food is culturally mandated, or culturally taboo, does not necessarily make kit healthy or unhealthy. But it does make it very hard to objectively assess whether a specific food belongs in your diet or not. Keep this in mind; your belief in the health-giving properties of apple pie may be unfounded in medical fact.

Food is a drug

The human body is a fantastically complicated machine, and the precise effect of any given thing on it is hard to predict. I think we can all agree that decapitation is unhealthy, and breathing air is healthy, but between those two extremes, there is a massive amount of variation. For example, I once ate a lovely healthy salad with chicken at a hotel in Edinburgh, while sat across from someone who would have been dead in 24 hours had she eaten the same. She was in the last stages of kidney failure, and the protein would have been utterly toxic to her. She died a couple of months later, having extended her life by several years by severely restricting her protein intake. So while it is important to have a good idea of what any given food tends to do to most human bodies, it is vital to know precisely what it does to your specific body. And just like with other drugs, a large part of food’s effect is placebo or nocebo. Honestly believing that cyanide is good for you does not make it so; but in the normal range of foods, how you feel about what you eat has an effect on what it will do to you.

Alcohol is a good example of this; there are measurable, non-imaginary chemical effects of alcohol ingestion; but the behavioral changes brought on by intoxication are entirely cultural. It makes you gregarious, or badly behaved, or whatever else it does, because you are conditioned to think it will by the culture you live in. Read Kate Fox on the subject here.

[Disclaimer; I am trying out Amazon affiliate links. So every one of these links below is one. I give you my word that I will only ever link to a book that 1) I own 2) I am glad I own 3) I think is truly relevant to the topic at hand. If I need to refer to a book that does not meet those criteria, I will note the title and author, but not link to it.]

The problem with doctors

Doctors, like soldiers, tend to be very conservative. If something appears to work, don’t change it. Don’t experiment. Because when the consequences of a failed experiment is people die, conservatism and caution are not just advisable, they are a moral imperative. Non nocere (do no harm) is the essence of the Hippocratic Oath. But this conservatism can also work in reverse; it took Dr Alice Stewart decades to convince the medical establishment that it is dangerous to x-ray pregnant women; thousands of children were killed by cancers caused by in-utero irradiation after she had proved that it was happening. (See Willful Blindness: Why We Ignore the Obvious at Our Peril, pp 60-67). So, just because a doctor says it’s so, does not necessarily mean it is. Doctors are highly trained experts, with a professional aversion to change, and they are all, every last one of them, human. It is foolish to think that doctors are infallible health gods.

So, the problem with doctors is often the patient. Doctors are not responsible for your health; you are. Doctors are professionals you hire to fix problems that are outside your competence. The person who services your car probably does not fill it up with fuel every time it runs low; you do. You don’t call a plumber to flush the toilet (I hope). The point at which your competence ends and you need to call in an expert varies hugely from person to person, and domain to domain. I don’t need a mechanic to check my oil level, but I never touch my car with a tool. I can change a washer in a tap, but I would not install a boiler. I don’t need a doctor to diagnose a cold, or to mop my fevered brow (that’s my wife’s job, poor woman), but if I can’t figure out what’s wrong, I call in a professional.

So a doctor’s advice on what you should eat will tend to stick with what usually works ok for most people, and be extremely moderate. It is very unlikely to hurt you, but it may not boost your performance at all.

Be a soldier or an athlete

World-class athletes tend to have their diet planned down to the last grain of rice (if their diet allows rice), and scheduled extremely precisely to ensure maximum performance at a single thing (running 100m OR a marathon; boxing OR wrestling) on a specific, known, future date. When the difference between Olympic gold and obscurity are measured in fractions of a percent in difference in performance, this only makes sense.

Soldiers on the other hand cannot tell in advance when they will be under fire, when they will be humping 25kg packs over desert hills or sprinting for cover through jungle, when they may be resupplied or when they will be living off the rations in their belt pouches for a week or even longer. So while general good nutrition is essential, and while a good quartermaster will win more battles than a good general, soldiers tend to eat what they can get, when they can get it. The key skill there is tolerance for variation.

In my view, martial artists (as opposed to combat sportsmen) should follow a healthy diet, yes, but never get precious about what and when they eat. “I didn’t get my organic bacon for breakfast”, or “I timed my protein intake wrong” are not valid excuses for losing a fight.

A good story is not always true.

“Fat makes you fat.” Makes sense, but there is bugger-all evidence for it. Plenty of people on a high fat diet are skinny- if they also avoid sugar. Likewise “Energy in, energy out.” Yes, the laws of thermodynamics are absolute. But the variables of what your body does with the energy that comes in as food are huge. A friend of mine worked in a lab where they put mice on a low-calorie diet, but also injected the hormone leptin into their brains. The results, in my friend’s immortal phrase: furry tennis balls. Food is a drug; some foods trigger fat deposition, other foods can trigger fat burning; the body is complex. See Good Calories, Bad Calories by Gary Taubes.

“We evolved in an environment in which certain foods were available; reproducing that (eg the Paleo diet) must be healthier, because it’s the diet we evolved to survive on”. Well, yes and no. I tend to agree that eating like a cave-man is probably closest to the diet we evolved to survive on, but: 1) we don’t know exactly what cave-men ate, nor how often. 2) Cave-men did not all eat the same things. Compare for example the known diets of pre-agricultural Native American tribes. Pre-industrial societies invariably eat what they can get. 3) We cannot reproduce all aspects of the cave-man diet, not least because the ranges of produce are huge, and locally specific. 4) We cannot know what else they did that may have improved their lifespan. For instance, for sure they didn’t sit on chairs, nor sleep in beds. But they also had a horrifically high rate of infant mortality, death by violence (pre-industrial tribes that survived into the modern era had rates of death by violence of about 25% of males. Today, on the mean streets of New York, it’s about 1 in 100,000, or 0.001%: see Stephen Pinker, The Better Angels of Our Nature). 5) Paleolithic life expectancy is generally thought to be pretty damn low. Was all of that environmental, or may some of it have come from their diet? We don’t know. 6) We do know that early agricultural societies appear to have much higher rates of disease and lower life expectancies than comparable pre-agricultural societies. Diseases such as diabetes, heart disease, arthritis and many cancers do appear to be diseases of modernity. But how much of that is down to diet as opposed to (for example) exercise? Nobody knows for sure. 7) Many modern inventions (like antibiotics and surgery) save lives. It is also possible that modern foodstuffs could, in theory, do the same (yes, I doubt it too. But you never know).

So, don’t be taken in by a story. Test any dietary changes systematically, give each change time to take effect (at least a couple of weeks, I would think) and be ruthlessly honest with yourself. Take nothing on faith (especially not a random blog post by some sword-swinging lunatic).

The 80-20 principle

In all things where you don’t want to invest major effort in becoming a world expert, the 80-20 principle (also known as the Pareto principle http://en.wikipedia.org/wiki/Pareto_principle) applies. It states that 80 percent of outcomes come from 20 percent of causes, and so long as you don’t take the numbers too literally, it is largely true. I do not agree with any diet that requires really specific foods at really specific intervals, unless you are seriously ill and under doctor’s orders, or an Olympic hopeful. If you’d like to see self-experimentation taken into 99.999-0.001 extremes (with a lot of good material on a range of health and training subjects), see Tim Ferriss’ Four Hour Body. The man even had himself fitted with a real-time blood-sugar monitor to test the effect of various foods. Fascinating stuff.

So here are some general guidelines, which if you follow them, will probably lead you to a healthy diet (and thus make you healthier, and therefore able to train more, and therefore a better swordsman).

1) Change one thing at a time. The first step, I would suggest, is avoid refined sugar. Nobody has ever demonstrated that it is at all good for you, so save it for treats. Be ruthlessly honest with yourself, and pay attention to what effect each change has on you.

2) Eat lots of vegetables. If it is not obviously part of a plant, it doesn’t count (unless you process it yourself). Major starch sources don't count either (potatoes, corn, grains etc.) Fresh and in season is best, frozen or canned are ok too. Michael Pollan is good on this: Omnivore's Dilemma, and others.

3) Eat high-quality meat only. Avoid processed stuff. This is not only a matter of health, but also of morality. What people do to cows to make them fat is way beyond disgusting. Cows should eat grass outside. (Be a vegetarian if you must, but veganism is, for the overwhelming majority of people, a deeply unhealthy long-term life choice.) See The Vegetarian Myth: Food, Justice, and Sustainability, for details.

4) Only consume things that have been produced the same way and product tested for a minimum of 500 years. Coffee, beer, tea, wine, meat, vegetables, bread (made properly, none of this absurd 20-minute rising nonsense), all good. Factory-produced stuff? Might be good, might be bad, you have no way to know. So be conservative. Food should come from a garden via a kitchen, not from a factory. See The Omnivore’s Dilemma (again), and Brave Old World by Tom Hodgkinson.

5) Cook. Take an interest in, and control over, what you eat. It doesn’t have to be complicated or take much time, especially if you are preparing food from good quality ingredients. By far the best book for people who might think “I have no idea about cooking, it’s intimidating and difficult” I have ever come across is Tim Ferriss’ Four Hour Chef.

6) Give each change time to take effect, before you assess its effectiveness.

Indicators of a good diet

When making changes to your diet, the key indicator is of course how you feel. But it is well worth keeping track of the following, to see what effect each change is having.

• Weight. Since dropping most sugar, and a lot of the starch from my diet, I lost 10kg in about 3 weeks). I now weigh 75kg, which is a kilo heavier than when I was super-fit and trying really hard to keep weight on, at age 30. Weigh yourself at the same time of day, and on the same scales, once a week.
• Waist size. Weight gain and loss can come from anywhere, and a lot of it may be simply water. As a general guideline, if your waist is smaller than your hips, you’ll fit into your kit better. But I find buying trousers is hell. If they can be pulled up over my thighs, I could fit a couple of hardbacks in the waistband.
• Poo consistency: as every parent knows, poo is a great indicator of general health. Parents, especially of babies, can discuss poo at length. Anything that makes pooing harder, or painful, or especially stinky, is probably bad for you. There is no better indication of good diet, really.
• Energy levels. These are very subjective, and can be affected by many factors other than diet. But if you find you need to snack to get through the day, you are probably eating sub-optimally. I found cutting sugar evened out my crashes very effectively.
• Frequency of minor illnesses: again, this is actually quite hard to track. But if a diet leaves you feeling tired, or it feels like you are more prone to picking up stray bugs, then abandon it. And vice-versa, of course.

In short, when it comes to nutrition, you should to pay attention to your body, read up on some sciencey books so you know what’s going on inside you, and use some good common sense. Fresh vegetables? Good for you. Ice-cream? Not a staple food. A martial artist must take care of their body; just as a soldier takes care of their rifle, or a swordsman takes care of their sword.

As always, share if you dare!

Incidentally, this post appears as part of the “Nutrition” section of my new book, The Theory and Practice of Historical Martial Arts. You can get a free 70 page sample of the book by signing up to my mailing list below.