Those trainings when you realize your dogi is liters heavier than it was when you started.

It’s interesting just how much water leaves the body during training.  We’re wearing layers of dogi and bogu.  We obviously sweat, even in winter trainings.  A large portion of that sweat is evaporated and goes unnoticed. There is also a significant amount of water vapor lost through breathing.  Still, I’ll hear horror stories about people who train and barely drink a liter of water a day.  Maybe they don’t realize that water is the primary medium for the body to expel cellular waste products.


In our dojo, we often remind students to drink water after class.  This is usually done as an announcement, a handful of times a year.  We typically remind our students to drink plenty of water throughout the day on both training and non-training days.  Along with the announcement is a general dojo culture that encourages dojo members to drink plenty of water before and after training.


We purposely don’t write rules or create mandates on most dojo norms and customs.  However; we quickly enforce a stop to certain behaviors that are rude, lazy, or dangerous. In this case, being dehydrated is immediately dangerous.  There is no dojo rule book or poster that dictates that we need to drink ‘x’ glasses of water a day.  But, most of us appear to take hydration rather seriously.

There are certain groups of people who believe that drinking more water than our level of thirst is detrimental.  I haven’t noticed this kind of view on water in my dojo, specifically.  There is a thought that drinking certain large amounts of water leeches minerals from the body.  While the reasoning appears to have flaws and contradicts my own perspective on drinking water, I personally find it is acceptable to allow people who feel this way to continue their habits of low water intake.  The unwanted conflict and imposing of opinion does not seem to be worth a slim chance of changing a person’s level of health.

Many students bring water bottles on to the training floor and in their bogubukuro.  As part of the teaching group, I personally decided to develop the habit of always having a water bottle out and visible during training and teaching.  Hopefully, this example will allow students to notice that teachers bring water bottles.  The students that notice this may apply the unspoken norm by bringing their own water.  The overlap (and differences) between enforced rules and emergent social norms are generally fascinating to me.  Each dojo appears to be an observable microcosm of larger scale society with a complex system of propriety and unspoken rules.

In a perfect world, where everyone takes in multiple liters of water throughout the day, I’d guess that there would be no reason to have water bottles on the training floor.  Perhaps, people would simply have drank enough water throughout the day to have adequate stores of water and relatively lower concentrations of cellular waste stored in their bodies.  After a 2 hour training, they would all simply drink water outside of the training floor to replenish and aid in the removal of increased cellular wastes from the training.   There would probably be no dehydration or symptoms caused by dehydration in this utopia.  However, people often don’t have such habits in reality.  This is probably why even the day-long hydrators in the dojo still carry those special water bottles with mengane penetrating straws around.


A shorter blog post on Hydration in Kendo
A longer article on Kendo related Hyperthermia, Water and, etc.

Articles like the one in the button above explain how many dojos, particularly ones in japan, would either prohibit or frown on drinking water during training.  It appears that the ‘no water’ rule was popular throughout Japan in other activities too.  Apparently, my mom’s volleyball coach in her Japanese highschool placed the same ban on water during even the more harsh practices.  She, and others who grew up in that era, have similar experiences in school sports.  It appears that there were some reasons behind refraining from drinking water during training.  Pushing against thirst and continuing to train was probably a training method to develop willpower and determination.  Not giving into the desire to drink water and focus on the training looks like a great skill to develop.  But, the cost of a few people ending up with heat stroke isn’t worth it to me.

I personally would be cool with training in a dojo like this, if the training time was under 2.5 hours.  I typically drink 4 to even 8 liters of water a day (depending on many variables like what activities I do and the climate).  I’d just drink water throughout the day before the ‘no water’ training, like the people in my utopia.

We can ban water drinking or even force people to drink water.  It could help or harm the people in the dojo in differing ways.  This is, on a dojo-wide level.  As an individual, I think it’s comforting to know that the ability to understand the causes and effectively prevent dehydration is well within our grasp.  It seems worth the time to experiment (over a long period of time) with some different levels of water intake.  This is, instead of relying 100% on whatever your dojo or people around you do.  There are tons of opinions on hydration. Asking around for effective information on water intake will typically lead to differing prescribed amounts of water and intervals of intake.  

Gradually increasing measured water intake throughout the day at comfortable levels over months appears to be one of the best ways to find the most effective amount of water.  This is my opinion.

Why so vague?

Like any cultural norm, the specifics behind the norm are often somewhat vague and harder to determine through observation alone.  This is; when compared to a written rule, law, or contract.  In rules and laws, specificity appears necessary for easier enforcement without dispute.  We can say to a class “Drink plenty of water throughout the day.”  We leave out of the announcements all the specifics.  Here are some unanswered, specific, questions that we would like to hear from the students:

Water based inquiries.


(1) How many liters/ounces, exactly, should we be drinking?

(2) Should I drink a half liter every three hours?

(3) Maybe I should drink a sip every few minutes?

(4) Do I need to drink water even if I don’t feel thirsty?

(5) How long does it take for the water that enters my system to be processed and useable by local tissues in my body?

(6) What are the symptoms of dehydration?

(7) Why are the symptoms of dehydration so general?

(8) Do drinks other than water count as water intake?

(9) Does distilled water really leech a significant amount minerals out of my body?

Closing remarks by a water enthusiast.

Someone could simply listen to the teachers and drink more than they already are.  But, there is so much more they could learn and apply, and this only has to do with drinking water.

It appears that instructors are often vague and limit their instruction.  After observing and talking to teachers who purposefully cut short their lectures, I’ve found the following.  They talk less, so as not to over-teach.  A teacher can easily answer this long list of questions (and more) by explaining in detail all the specifics of hydration.  However, we purposely leave out all the small stuff in our dojo.  Many students don’t want to listen to a 20 min lecture on the virtues of water drinking, anyway.  We can explain all the details of how to do something.  But, that lecture is wasted if the information is never applied by most students.

My hope is that (1) students will be genuinely interested and curious about water, (2) students will go and ask the teaching group about the specifics, and (3) the student might even be interested in improving their iternal level of health through using the resources that are offered at our dojo.

It sounds like an exaggeration, but I’m pretty sure that our particular kendo dojo has more knowledge in health preservation than any other kendo dojo Ive been to.  I’m also sure that most all dojos, even in Japan, lack the knowledge of health preservation that we have here.  Despite this resource being quietly available to all students, fairly few have actually talked to our dojo leader and genuinely practiced what he has to offer.

So, feel free to drink more water.  Even if you never have the desire to know the specifics.