I’m not an active person by nature. I have a sedentary job. Hate the gym. Don’t play sports (other than paintball in my youth). Not an outdoorsy type.

So, I thought it was pretty cool when I lost 20 pounds about 11 years ago when I first started kendo, and went from 225 pounds to 205 pounds.

And then the weight slowly crept up again, and I found it harder to keep it down the older I got. This is also about the time, I was solely responsible for getting my kids to and from practice at the expense of my own practice time, until one-by-one each of them decided to do something else.

Enter COVID in March 2020 and the pause in organized kendo. With that, the weight steadily increased to beyond pre-kendo levels. We wouldn’t start practicing again until May of 2021.

With a lot of help and motivation from my senseis and dojo friends, I was able to pass the yondan exam. With that came a sense of relief. I was able to learn to relax and actually enjoy kendo more. While helping others, I found myself spending less time waiting in line and more time actively doing kendo (I still have to figure out how to balance practice so that I get my time in with the higher ranked senseis). But I’m quite happy that the numbers are going in the right direction. And that I can put away the XL large do and bring out the original one I first started kendo with.

So what did I learn?

  1. For me, Kendo is a pretty fun and efficient way to burn calories. It is not uncommon for me to burn at least 1000 calories per kendo session. And keep actively burning calories that evening while sleeping/recovering.
  2. You have to do some activity/exercise (even a little) on the off days. My insurance incentivizes me to be active 6 of 7 days a week by earning points for gift cards (I end up giving them to my daughter for things like Starbucks). Activity is tracked by either an Apple Watch or Fitbit. (Is it accurate? I don’t know, but I’m happy with the results).
  3. Even if you are hungry after practice, don’t eat a heavy meal. Especially no fast food on the way home. I’ve been trying to just eat a little fruit.
  4. Water. I drink enough throughout the day that it forces me to get up from the desk and use the bathroom at least once an hour.
  5. Intermittent fasting. On some Saturdays or Sundays, I try to skip breakfast and eat late.
  6. On some weekdays, I eat a late lunch and then have less at dinner (regular time, not late).
  7. On Kendo days, I can eat a lot more.

Ozone Sanitizing Water Spray Bottle

So I purchased this on demand ozone water spray bottle, manufactured by @o3waterworks with an MSRP just under $200.

I was a bit skeptical since this just happened to popup on my insta/fb timeline with not the most professional or flashy marketing campaign.

However, after reading a lot of reviews and seeing a similar product at my dentist’s office, I thought I would give it a try.

It seems ozone infused water (aqueous ozone) has been used as an industrial disinfectant for sometime now and for cleaning the food and water supply.

While gaseous ozone (O3) is a pollutant and hazardous to our lungs, aqueous ozone is relatively safe to humans and degrades to oxygen (O2) in water. The half life of ozone is about 15 minutes. That means every 15 minutes about half the remaining ozone will become oxygen.

Ozone is an oxidizer which can destroy bacteria/viruses/fungi. It also can deodorize by destroying odor causing molecules, organisms.

So, a part of any strenuous activity is usually associated with sweat. Sweat is accompanied by strong odors. We try to limit these odors through cleaning, using a barrier device/fabric, cover up odors with stronger odors and ventilation.

While I wipe down my bogu with a wet cloth after practice I don’t generally wash or rinse it (especially since I don’t have that many sets of bogu to exchange with while I wait for the other to dry). Which — I admit — is just gross. In the past, I’ve used hockey spray (some use Febreze), a sport dryer, plain old leaving the bogu overnight outside, so who knows how much dead bacteria and other organisms have accumulated over the years.

So having a spray that can both deodorize and disinfect seems like a winner to me. Will this replace occasionally deep cleaning of the bogu? Probably not, but it should be better than nothing.

So how does it work? An electric current separates O2 gas into two separate ions. One of the ions will combine with a gas molecule to form ozone (O3). Eventually the ozone (O3) will lose an ion and return to it’s more stable gas state (O2).

The spray bottle is weighted on the bottom, probably housing much of the electronics. The neck is ergonomic. It utilizes a push button electric trigger rather than a mechanical one which is pretty cool as there is no hand fatigue. There is a charging port on cover on the top right of the bottle and the top of unit has indicators for help in determining proper operation and error codes.

The 10 oz capacity reservoir has a semi-firm plug. It is easy to fill via faucet, just don’t use distilled water (per the warnings). I found it difficult to judge the max fill line while the bottle is tilted for filling, but no worries, just tilt the other way and it will spill out. They also warn you not to operator the spray without any water.

The included charger has a green indicator to help you determine if the unit has been fully charged. They recommend you top off every day to keep it fully charge.

The spray comes out not as a mist or a stream. So it’s easy to saturate an area quickly. Also the spray does not pulse, it appears to be continuous. They recommend optimal distance of 6-8 inches.

When you first begin to use it, it will not spray which was at first concerning. However, if you hold the spray button down, it will eventually prime the pump and you are good to go.

So I’ve had this bottle for only two days now and I think it does make a difference. In the immediate time after use, it does have the smell of fresh rain/ozone. I store my bogu in our converted garage/gym and on some days it’s pretty rank. However, after the spray, it seems to have been muted. I have taken a whiff of the kotes and there is still a smell. But I don’t know if this is due to residual build up or if it is the natural smell of the smoked leather. Anyhow, it seems to have made a difference on the chin pad of the men, the tare and the himo.

Time will tell if the aqueous ozone causes any fading of the indigo dye, but I have been told officially that it does not or to test in an inconspicuous place first.

I’m going to continue to use it and will update this entry if there is anything else.

The nice thing about this spray is that it is not limited to deodorizing/sanitizing bogu or sportsgear. I can use it in the kitchen to spray down veggies and fruits, sanitize the sink, disinfect the doggie bowl, spray down surfaces, pretty much use anywhere you would like to clean without resorting to detergents or bleach.

Note: I did not receive a free unit or get paid by o3waterworks for this review, but if they want to send me another spray bottle, I will gladly take it *wink wink*.

New Bogu Bag

So I finally got tired of fixing my last non-kendo bogu bag (see, and after a few months of searching I purchased this bad boy from Thule.

The Thule Subterra 25 inch/63 cm Spinner combines a soft front and reinforced sides and a textured skid plate in a stable vertical platform. It has an extendable handle on the rear of the bag and has two locking positions. While most handles have a release button on the top, the Subterra has two buttons on the side to prevent accidental release. You can press either button to release the handles. Two reinforced ballistic nylon handles on the top and on one side of the bag opposite the zippered opening. All zippers have reinforced eyelets. The front wheels are smaller so that they do not encroach on the internal cargo space. There is a mesh pocket for a business card to be used as ID. Comes in black, blue and burgundy.

The svelte Subterra has outer dimensions of 12.5 x 17.3 x 25.0 inches (31.75 x 43.9 x 63.5 cm) and is quite compact compared to my last bag, Planet Eclipse GX Split ‘Compact’ gear bag which was quite bulky (35 x 40 x 65 cm). I don’t know anything about capacity but the Subterra is 63L and the Split was 91L. The Subterra can also expand two inches via zipper extension. The main compartment can fit my XL E-bogu do and men (10.5 x 16.5 x 19 inches, self measured). I put the hakama and gi in the bottom zippered compartment and the tenugui and other stuff (contacts, tools, first aid kit, tasuki, probably shinpanki too) in the top compartment which can be accessed from the inside of the bag and also from the top of the bag.

It’s pretty light since it’s not a hardside and should be easy to wipe down both inside and out.

The bag is pretty stable upright and I have not had it tip over yet.

When full, there is a little bit of resistance on one side of the zipper which you have to be a little patient to close the bag. I might put a little candle wax or chapstix on it so that it will be easier to pull.

Right now, I haven’t really figured out if I am going to put wet gi/hakama back in the bag or carry a separate drawstring bag.

At 399.95 (430 USD with tax) it’s a bit pricey but I’ve been told the kendo traveller bags from tozando are about $300 (after shipping) but are a bit heavier.

It does the job while looking great. There isn’t any really extra wasted space. But I wished it came with a few more pockets and maybe a velcro panel or two for my patches.

Some other bags I had considered:
Virtue High Roller v4 – too small (15 x 16 x 31 in; 38 x 40.6 x 78.7 cm)
Ruthless Pro Duffle Backpack – too small (12 x 12 x 25 in; 30.5 x 30.5 x 63.5 cm), not rolling
Dakine 365 Roller 75L bag – too small (11.5 x 14 x 28 in; 29 x 35 x 71 cm)
Northface Rolling Thunder 30” Roller – (13 x 16 x 30 in; 33 x 40 x 76 cm) not a spinner

4 Dan exam question

So last November, I was fortunate to have passed the yondan exam after the Covid hiatus.

Part of kendo exams are the essay questions. I chose “Describe the benefits of the Kendo kata (剣道形)검도형 and its relevance to shinai keiko (竹刀稽古)죽도계고;.

Kata is defined as prescribed, choreographed movements or a training exercise meant to preserve and pass on knowledge or techniques of a martial art. It is not only a physical but a mental and spiritual exercise. With much practice, the elements of kata can be incorporated into shinai keiko.

Prior to the development of kendo bogu and the shinai, students of the sword could only practice kata and engage in live duels. But with modern kendo, new techniques were adapted for bogu and bamboo swords that were not true swords. To remain true to the study of the sword, it was necessary to continue the practice of kata with bokuto that simulated the heft, feel and dynamics of a katana. Otherwise modern kendo would become a sport rather than a martial art.

Like shinai keiko, kata requires two participants. For there to be set patterns of behavior and choreographed movements, just like dancing you need someone to lead. So, in kata we have the uchidachi or striking/attacking sword (the one that leads/acts) and the shidachi or doing/receiving sword (the one that follows/reacts). In shinai keiko, the participants assume these roles, alternating between uchidachi and shidachi in the same match multiple times but less formally and less choreographed.

Kata and kendo training start with respect (reiho). It begins and ends with a bow. Respect for your partner translates to caring for the other person because we don’t want to injure them while practicing with a wooden sword and no armor. This should also reinforce respect for each other during shinai keiko.

In order to be safe during kata, we learn the correct distance, timing, posture and correct body movements through repetition. Correct distance, timing, posture and correct body movements or mechanics also translate into better striking during shinai keiko. With enough repetition, these mechanics become internalized or muscle memory and the mind can become free (mushin) from surprise, fear, doubt or confusion.

We learn to harness our spirit or energy through proper breathing, kiai (yaa and toh) and zanshin. We also learn to conserve energy by becoming efficient and minimize unnecessary  movements by keeping things simple.

Kata teaches focus. There should be no relaxation of concentration. The same goes for shinai keiko.

While kata relies on repetition, it is not a static or rigid process. The kata forms have been revised multiple times (1906, 1912, 1917, 1933, 1981) since being instituted. Although there are prescribed movements, they are slightly different for each person (and for even for the same person) each time they are performed. It is the mental focus, the spirit, and the response that should remain the same.

Kata as a part of kendo fits in well with the purpose of practicing kendo as espoused by the All Japan Kendo Federation. It molds mind and body through intense mental focus and physical repetition. It cultivates a vigorous spirit through “yaa and tou” and response of the tachi/kodachi. It is correct and rigid training through carefully choreographed movements, striving for improvement with careful attention to courtesy and honor (respect), sincerity (seriousness) and cultivation of oneself through ten kata that we practice and continue to improve.


Bennett, Alexander C. Kendo: Culture of the sword. University of California Press, 2015, page 44.

Donohue, John J. Complete Kendo. Tuttle Publishing, 1956, pp 110-12.

Inoue, Yoshihiko. Kendo Kata: Essence and application. Kendo World Publication, 2003, page 156.

Ozawa, Hiroshi. Kendo: The definitive guide. Kodansha Intl, 1997, page 98.

The creative process

Maybe you are wondering what it takes to come up with a new patch or sticker.

So I thought I’d go through what it took to come up with one of the latest drops.

I get inspiration from random things in pop culture. Sometimes they can be well known. Other times, they may be more obscure. Sometimes current themes, but other times you might not get the reference.

So, for the latest inspiration, I took it from Will Ferrell and John C. Reilly:

There are a few fist-bumping Shake and Bake items out there but none relating to kendo. So I thought I’d put my spin on it.

First I set up the shot by taking a picture of my kotes on a white background.

There is some shadow but we will get rid of that later.

The photo was cropped.

Then the image was traced and processed using

Instead of using Illustrator, I use a vector program called sketch. It’s a vector design and prototyping app for Macs for apps and web interfaces. But you can use it to do basic vector design. Much cheaper than Illustrator (no subscription).

Added an indigo background and inverted the kote color.

Then I added text and added racing stripes,

Finally I added a starburst to give a sense of motion/impact.

Spryng compression sleeves

So I took a chance on an indiegogo campaign and purchased these compression sleeves from

Spryng claims to decrease the recovery time for calf muscles after exercise.

SPRYNG™ contains an innovative, patent-pending WaveTech® graduated compression pattern that prevents leg swelling and improves blood circulation. It does this by mimicking the skeletal muscle pump that occurs following strenuous exercise, aiding in the return of blood to the heart so swelling and muscle injury is reduced.

So what you get is a pair of one-size-fits-all pair of active compression sleeves, carrying bag and charger.

The dimensions of the bag with sleeves and the charger is about 14 x 7 x 4 inches, so this can fit in a backpack and easily into carryon luggage.

Each sleeve is labeled either right or left and is placed on the top of the foot and attached by velcro on the back of the leg. At first I had some difficulty putting on the sleeves because I have thick calves and didn’t realize that I was wearing the sleeves too high (I did contact customer support and they did notify me that they would be shipping out extensions for those of us who are well endowed).

Label on the inside of the compression sleeve.

Operating time after charging (about two to three hours), is about 15 minutes with up to 10 cycles of use between charges. The sleeves are turned on by holding down the center diamond button until the LED indicators come on. They are turned off by holding down the same button. The arrow up button is used for adjusting pressure and the double diamond button is for adjusting the compression pattern.

What makes this product unique is that it is active compression mimicking the natural compression in your leg without being tethered. The sleeves can be worn with or without clothes and you can even walk around while using them. However, they are not meant to be used while being active (only for recovery ) and not to be immersed in water.

Sleeves can be worn over clothes (jeans).

I have used them for over a month now, two cycles after coming home from practices (and after a shower) and I can say my legs feel much better the next day and I have not had any muscle spasms (Charley-horses) waking me up in the night since then. They are easy to clean since the material is nylon and the inner liner which is attached by velcro to the sleeve is washable.

Some caveats. They aren’t cheap. The current price for a pair is about $250 in the US (includes shipping). It took me awhile to receive my sleeves mainly because they were having trouble with the FDA importing them into the US. I still have a couple warning letters from the FDA that I may or may not need to respond too (still waiting for spryng to respond but in a blog post prior to delivery, they had said I would not need to).

[Update: after back and forth with FDA, FedEx and spryng, FedEx finally agreed to take back the units so they could comply with the FDA. I received two BRAND NEW units, one of which was also quickly replaced for a malfunctioning sleeve with another brand new set. All of this without their knowledge I was reviewing their product. Kudos to you guys!]

Also, when first charging the units, the charging ports are really shallow. So don’t try to force the charging receptacles on the charging, they just barely hang there.

Charging port at top.

Compact active compression sleeve that just works
More or less one size fits all

Took a long time to receive (warning letters from the FDA)
Charging port is shallow
May not fit as well for those with really thick calves (but extensions planned)

[Update: I received two sets of extensions free also. These also attach by Velcro.]

$249.99 USD (free shipping in US)

1 year against manufacturing defects


From last night’s/this morning’s toshigoshi practice:

Your kendo is like 3/4 or 4/4 time [its predictable].

Try 1/8 or 2/4 time.

Paraphrased from Steve sensei, [kendo is like music, mix it up]


I keep coming back to the meaning of sen.

awareness; anticipation; readiness to act

It’s not that I’m overly forgetful but it’s useful to review.

Sente. “First move , initiative ”, abbreviated as sen. The idea of sen is that one is“ready to act”. 

An essay I found by Stephen Quinlan from 2011.

From sen we get the mitsu no sen:

  • sen no sen – I strike you as you begin your attack
  • go no sen – I strike you while you are attacking me
  • sen sen no sen – I strike you just before you begin your attack

One of the references I find most useful is this one from George McCall back from September 2015.

I think this is worth reviewing over and over.