One Simple Exercise to Increase Your Flexibility by 39% (Or More) in 8 Seconds

Picture this:

You’re sitting in heavy traffic, on your way to the dojo.

You’ve had a long week at work, and it’s finally time for some good old Karate.


You hope that your sensei will teach you something new and exciting today (“maybe a new kata, or some cool takedown technique?”) – because your patience has been tested all week with angry customers and now you want to have some fun.


When you finally arrive at the dojo, this is what your sensei greets you with:

“Hey! Today we’re gonna practice the basics. Again and again. Nothing else. Just kihon!”


“Ugh, w-what…?!” is all you manage to blurt out before your sensei skips away.

Dang it.

It was a shit-sandwich and you ate it.

You’re ashamed to feel disappointment and anger at this point, but you try to think positive. You try to act grateful for this wonderful opportunity to repeat the same old goddamn techniques over and over again – for two hours straight.

  • You look at your car keys.
  • You look at your bag.
  • You could have gone home, you know.
The greatest treasures hide under the greatest obstacles.

But you decide to stay and practice anyway – even though it will probably be the worst class in the history of mankind.



Turns out, it was one of your best decisions ever.

Because, after training you feel AMAZING.

Like a million bucks.

Like you’re floating on a giant cloud of whipped cream, surrounded by golden butterflies with Nutella-covered wings and hot chocolate fountains.


And the butterflies serve you magical carrot cake infused with giant strawberries and rainbow roll sushi, while the sountrack for Fresh Prince of Bel-Air plays in the background on repeat.

“Na-nana-na-na na…”


[Jesse-san, snap back! You’ve got an article to write!]




That training session was so amazing that when you got home you ran straight to the computer to write an e-mail to your favorite Karate Nerd™.

That’s what Colleen-san, from South Africa, did the other day, as she wrote me:

Yesterday I was feeling like I wanted more from karate, and was feeling dissatisfied. Then I went to training and we did kihon, again, which was exactly what I needed – not to learn something new but go deeper into what I know, focus on my technique and realize I still need to work on it.

I think we can all learn a lesson from this.

Our greatest insights often come from exploring the depths of our basic knowledge – not the breadth of our technical registry. (Click to tweet this.)

When in doubt, always practice the basics.

More smash, less flash.

A common PNF technique with a partner.

But sometimes, it’s not enough to “just” practice harder or deeper.

Sometimes we need more.

Something that will get us unstuck. Like a specific tactic or method, that will help us achieve the quantum leap we’re longing for.

Well, today I got one for you.

It’s called ‘proprioceptive neuromuscular facilitation stretching’ (PNF) – and is one of the best, yet least known, ways to boost flexibility to a ridiculous degree.

I learnt this specific flexibility technique at an advanced sports coaching course a couple of years back, and have been using it to great success with my students.

If you don’t believe me, listen to this:

When I showed this simple stretching exercise to Anette, a brown belt woman in her mid 40’s at our dojo yesterday, she literally increased her flexibility by 39% (that’s 7.0 cm/2.75 in difference) right there, on the spot.

Just like that.

And the best part?

It took her 8 seconds.

(That’s right.)


So, what kind of magic is this? No magic. Just some good ol’ science. Allow me to explain, and then you can try it out for yourself.

It’s super simple.

Here’s what you do:

(Thanks to sempai Michaela and Elin for demonstrating the exercise!)
  1. Stretch as you usually do. You can choose any stretch. In this case, the illustrations show a classic inside groin/thigh stretch (often known as the ‘lotus flower’ position).
  2. Contract for 8 seconds. Either with help of a friend, against an obstacle or against yourself. Make sure the pressure activates your antagonist (opposite) muscles.
  3. Relax. Then repeat the process a couple of times (3-4 times is enough).

There you have it.

One simple exercise to increase your flexibility by 39% (or more!) in 8 seconds.

This can be used for all kinds of stretches; hamstrings, hip flexors, glutes, calves, chest, shiko dachi, splits – you name it.

Just figure out the opposite direction of any stretch and apply pressure in 8 second intervals – against the floor, yourself, the wall or a friend – combined with pauses of relaxation and passive stretch.

That’s it!

But before I let you run off with this exercise, I need to ask you something:

Do you really need more flexibility?

See, when people say “I want more flexibility” they often mean “I want to kick higher”.


But flexibility alone won’t make you kick higher.

(In fact, research shows that too much flexibility is actually bad for performance.)

To kick like Chuck Norris, you need:

  • Balance
  • Strength
  • Flexibility
Flexibiliy is what gives you the potential to kick higher, but strength (i.e. in the end-range of motion) is what actually takes you there, and balance is what let’s you stay there. Make sure you practice all three to kick better, higher, faster and harder.

(And if you’re kicking an opponent, you need even more stuff; power, timing, distance, speed, accuracy, strategy etc.)

In other words, flexibility is just one single piece of the puzzle.

Keep this in mind.

Lastly, for those of you who think you’ll never achieve any impressive degree of flexibility, please ponder what Itosu Anko, the grandfather of modern Karate, wrote in his 1908 seminal treatise on the essentials of Karate:

“A torpid bull, regardless of how slowly it moves, will eventually cover 1,000 miles.”

And the journey of a thousand miles always starts with a single step.

The best time for flexibility training was twenty years ago.

But the second best time is NOW.

So go flex!

(And bring a measuring tape to share your results in the comment section.)

Good luck!



  • Chris
    Funnily enough my physio was doing this with me just yesterday. I'm hyper mobile and horribly inflexible but after doing this for a few minutes my legs were all over the place (in a positive, physical therapy sort of way). I intend to do as much of this as possible while I'm off injured in the hope of coming back a bit more bendy!
  • Hi Jesse, just thought I should improve my stretching. Were thinking of doing yoga for that purpose. I'll think better now. Saludos desde Chile!
  • Great post, Jesse, this is a technique I use and it works wonders! Your point at the end really stood out for me, that flexibility isn't everything. I can do the splits easily but when I kick I can only go to shoulder level. I never really saw this as an issue as I'm not yet convinced that kicking splits are necessary but I am curious. I feel my lack of kicking height is definitely a strength issue but I can't figure out if it's my core or my legs or both. If you or anyone has any idea I would love to know!
    • Jason
      Stand up straight and hold one leg out horizontal. Now try to raise the height of the extended foot as much as possible. Once you get to your limit, lean away from your foot. Can you raise your foot further? If you can, in most cases, it's your strength that's lacking. If you can't, it's flexibility.
    • Erik
      Hey Claire, Would be way easier to pinpoint the strength deficiency without actually seeing it but it sounds like it's probably a hip extensor weakness. When you chamber your kicking leg, how high can you get your knee, and can you keep it there? Keeping your leg totally straight, can you raise your leg to waist level and keep it there? If you do a stretch kick (where you keep your leg straight and just swing your leg straight up) can you get it above your shoulder? Could also be back flexibility, can you get into a back bridge or into a full squat?
      • Hi Eric, thanks for these questions. I can chamber my kicking leg to shoulder level and keep it there. I can also extend my leg out forwards and sideways to waist level and keep it there and the stretch kick goes above my shoulder. But you've just reminded me of a related challenge, ura mawashegeri. I don't have alot of power there compared to other kicks and I think this is due to hip entensor weakness as you suggested. I've been doing additional work with a personal trainer to improve my combination of strength and speed in karate so will include this. Thank you again!
        • p.s. Forgot to metnion Eric, I can do the full squat and back bend. Teaching and practicing yoga keeps me (mostly) bendy!
  • This is gold:
  • Dia Sarkar
    i am Dia Sar kar, green belt, i want good stanching, but i can good state stanching, so please help me good state stanching for improved my karate,
  • Stonerose
    I suppose I never did it in exact measured time limits, I would just do these stretches quite at random(I know that's terrible). I'm 24 and a brown belt and frankly, I do have a very rigid body after I have passed that age where your body is very malleable and this is something that I really need to do. But I do have one question, how exactly do you measure the actual flexibility?
  • Jordan
    Dude,I am BLOWN...AWAY. I've been stretching every day for about an hour, and before I read this article tonight, I was pushing myself (quite painfully) towards the toe of my right foot, still about an inch away. Then I read this article...Contracted my hams and calves, got back on the floor quick and ****ing BOOM...Could touch my toe to the first knuckle of my finger. I feel like I'm dreaming. Jumped up again, contracted, got back down and boom, same thing with my left toes. And THAT'S THE HARDER REACH!! Thank you for sharing this info. I can't wait to share this and use it 2x a day.
  • Julian Easterbrook
    Well here's a shocker for you - it doesn't work for me - and these exercises have been central to my training for 19 years. I'm almost 69 now train 6 times or so a week - do plenty of gym work, weights and cardio, but practice a range of Katas to genuinely see where my flexibility is. My 'jumps' are okay - not the same as someone half my age, but they are okay. I don't chase down the myth of wanting to kick head height - great for 'Hollywood' but concentrate more on destabilising an opponent with kicks and sweeps below the groin. What I would say to people though is if it works for you great - but some of us are just built different and can adapt in other ways.

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