I changed my mind

Updated – see below

Between positing the last article, and updating it with information from various later-published missives, I re-started keiko trying to follow the ZNKRs guidelines. In particular I wore a “men-mask” around my mouth and nose (a tenugui used bandana style) and fitted a plastic mouth guard. I did these in various combinations and practised for five days . The last three of these days overlapped with the start of Japan’s rainy season (i.e. I practised in high humidity). I was initially given a pre-made men-mask before experimenting with my own designs. 

In my original post I said I was hoping to try a plastic face guard but that:

“I know already already that it’s a lost cause, especially in the heat and humidity Japan experiences.”

After the ZNKR issued it’s guidelines I said about wearing the combination of bandana tenugui AND face shield:

“Nope, no way.”

I also said that the:

“…tenugui idea in particular seems unrealistic. I am willing to give it a go though…”

I also added that there was:

“no chance I will wear both simultaneously…”

In other words, I had decided what I was going to do without actually experimenting myself. That was wrong of me.

Now that I have actually tested things out, here are my impressions. 


When I went to the bogu shop to pick up the plastic mouth guards there were some separate eye guards as well. However, it was recommended that I didn’t use them – the problem being that once you clicked the eye guard into place  it probably wouldn’t come out with breaking it somehow. The mouth guard, however, could easily be put in and taken out. I have yet to try a full plastic face mask.  

Plastic mouth guard (top), and a variation of the “men-mask”

With a willing partner (who was always wearing something as well) I tried out the following:

1. plastic mouth guard only 

- The mouth guard fits easily. 
- You can do keiko as normal, with no difficulties. 

- It clouds up sometimes, but since its below your eye-line it should be ok. 
- It is highly questionable whether it stops any sort of transmission. 
- The guard could potentially fly out it not fitted properly, if you go in to some strange shape, or are struck in the men or mengane awkwardly. It rests pretty close to your eyes, so this is a real worry. 

2-tenugui bandana only (various designs)

- The ZNKR strongly recommend that you do this as it can help stop the spread of virus. Exactly how much might be debatable, but it does at least aid somewhat. 
- It's cheap. 

- It takes getting used to.  
- It restricts air flow and could be potentially dangerous.
- It feels hot.
- It feels tight (at first).

3. tenugui and plastic guard

- The ZNKR states that people over 60 should wear this combination (actually, an eye guard as well) as it offers the best protection from spreading and catching the virus. 

- It can feel somewhat claustrophobic.
- It restricts airflow further than a tenugui mask alone therefore it is probably unwise to do this if you have some sort of underlying health issue or are simply unfit. 

Basically, after a few days of trial I can say that – for me – I could comfortably wear both mask and guard together without any severe problems (even with a beard). Note that I have a quarter of a century experience in kendo, I am fit for my age (mostly!), and have no underlying illnesses – you may experience things differently depending.

The maximum time I spent with my men on was 40 mins. I did kirikaeshi, some kihon (men, kote, dou, tsuki), a bit of jigeiko, and some light uchikomi and kirikaeshi to finish. I kept my FitBit on as I was doing this and could measure my heart rate.I am also pretty old (I’m 45 but feel – and look like – 65!) so my keiko wasn’t nearly as intense as it used to be, and certainly wasn’t nearly as intense as my students usually do. 

My real fear during this was not the risk of heat stroke as much as the plastic guard flying out and in to my eye (or even shattering). We even tested a few “face tsuki” to see if could be dislodged (receiver closed their eyes) – it didn’t. Still, it makes me uneasy. Perhaps a full plastic face mask would solve this problem, I am not sure. 

Close up of how the mouth-mask “fits” in (=is jammed in to) the men

Direct contact with the ZNKR

During the week I reached out to the person responsible for doing the science behind the ZNKR guidelines.  I did this because the re-starting of my school kendo club is imminent and, as the boss, I had to be sure what I was doing was as good as it could be. Truth be told, I needed some extra assurance.

Up until that point I had planned to have the students wear only the plastic mouth guard (while the teachers wore both items) but after talking with the gentlemen, I decided to reverse that: make the tenugui mask a requirement, and not force the wearing of the plastic guard (this would help allay my worry about them flying in to peoples eyes). I will make everyone buy a guard anyway, and we will use club time to make the tenugui mask to ensure that everyone has at least one of those as well. Perhaps I will enforce the use of the plastic guard while doing controlled keiko only (= kihon). 

He also let me know that the ZNKR was currently researching the potential of using a different material for the mask, something easier to breathe through, and that we should hear the results of that research around about the middle of the month. 

In conclusion 

My initial reactions to the ZNKR guidelines were a bit over zealous. If we are going to re-start kendo (my students will not put men on for at least another two weeks+) then I think a tenugui mask is inconvenient but certainly do-able. It’s not as terrible as it looks.

The plastic mouth guard I am much more wary about. Not because I don’t think it can’t help with the current corona problem, but because there is possibly a potential chance of it dislodging.

If nothing else happens I plan to re-start keiko fully (though slowly) at my club in just over two weeks.I will let you know how it goes. 

btw I actually believe that no matter how my club adapts our keiko for the current station, there is far more chance of the virus spreading in school simply because each class has 40 students ram-packed into a tiny room where they sit in close proximity for 6-7 hours a day. Multiply that by nearly 30 classes and the fact that about 70 teachers are constantly moving between classrooms each period and boom… 

Update (25th June 2020)

Since originally posting this article I have continued to keiko as described above. The only further experimentation I did was with a full-face plastic guard (while wearing a tenugui mask at the same time). I haven’t done so much keiko while wearing one at the time of this update, but my initial impressions are:

The good: it fixes easily into position; it is made of soft plastic and addresses any fear of breaking or flying out  mid-keiko into your eyes.

The bad: wearing one is pretty hot; although it was anti-fog, it did kind of get vaguely hard to see, which I must admit didn't like.

The ZNKR published more details yesterday following on from further research plus attempting to address peoples concerns. The gist of the matter is this:

* at the very minimum you should wear a tenugui mask with a mouth guard;
* the tenugui mask only needs to cover your mouth, not your nose;
* there are many other materials that seem to be better at soaking up spit than tenugui, so please experiment and use what you find works.

That’s it for now, more updates when/if they come.

Useful links (added 27/6/2020)

* Face Masks & Protection FAQs
* The Right Mask for the Task
* Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

By George

George is the founder and chief editor of
For more information check out the About page.

11 replies on “I changed my mind”

George, thanks for a great piece of advice. We are reopening next week, thus I will gratefully employ it and force people to wear tenugui-maks only with respect to convenience and safety reasons. Pleasure hearing you as always!


Glad you got something from my article!

The ZNKR would prefer people to wear something that comes in contact with your mouth (the material can be tenugui, but some other stuff is better) plus some sort of mouth guard if possible. In my trials, it isn’t as restrictive as you might imagine. Cutting a tenugui in two, folding it over and putting some string in there is very easy, not to mention cheap. At the very minimum do that. Many kendo manufacturers have come up with various protectors but with a bit of ingenuity you could probably make something as effective without spending too much.

People more susceptible to covid-19 (older people or those with pre-existing conditions) need a lot more care. Perhaps they should wait it out.

Thank you McCall sensei for sharing this. I was wondering what the experience would be like and am most concerned with any physiological or psychological effects (which could vary across individuals) that may arise from the constrained airflow. This helps a lot 🙂

Really useful article George,especially the updates. Any more news? Your articles and updates are the most up-to-date info I’ve received so far.

My clubs still hasn’t started back in the dojo yet but are looking to discuss our options. My hometown just experienced a spike and is going back into lockdown, so the immediate future is unclear.

I noticed you have a half-face plastic mask in the top picture, but you look to have trained at a later date with the full face version. Does that mean the half face is not recommended?


Hey Ben,

Sad to hear you are going back in to lockdown. Be safe please.

As for updates … as far as my experience goes I can say for certain that the plastic mouth guard plus tenugui “bandito” works fine for keiko. I am unsure as to its anti-virus quality though. I won’t argue and follow the experts advice. Many people here are trying to “cheat” by using something thinner instead of following the guidelines.

The full face guard I got came out later because – i think – that particular company took the situation a bit more seriously and attempted to address it. Unfortunately, those guards are (the one I tried anyway) super stifling.

There have now been multiple reports of eye-guards cracking and splitting …. so I would avoid them for now.

My take is this: at minimum use a mouth guard and some sort of wrap around your mouth (not too thin). Avoid separate eye guard pieces (at least for now) and full face designs …. not recommended.

Hi George,

Looking at the photograph with the mask made from a red tenugui, that looks like some very impressive needlework. Can I ask if it was hand, or machine-stitched?

Thank you sensei for this great article. With community flattening vote curve in summer we had returned to open air park practices and just drills wearing medical grade KN95 masks under our men. Close contact keiko and taiatari not permitted. Now with community infection rates going up we are taking a pause again. I’m going to pass this article on to my sempai in charge of practice to see if we can obtain some mask shields. It’s too bad the pattern is not available open source so others can just copy and cut their own shields. Material is easily had since it’s the same plastic used in dollar store disposable face shields.

Hey John,

I think you could probably make your own ones with a little bit of tinkering around. Even very soft/flexible plastic could be used.


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