What do You Mean When You Say You are Strong?

You must know this… It should be basic knowledge for every Karate Coaches.

One of the most misunderstood subjects in Karate and Sports, in general, is the concept of “being strong”. Who is stronger:

  1. A Karateka that jumps higher or a Karateka that lifts more weight in a single squat?
  2. A Karateka that makes 50 push-ups in a row or someone who punches a heavy bag with more power?
  3. A Karateka who is able to keep a perfect Shiko-Dachi or Neko-Ashi-Dachi for 5 minutes or a Karateka who knocks you down with a single Mawashi-Geri to your leg or trunk?

These are good questions!!

Let’s see it from a very simple perspective: they’re all strong but in different types of Strength and different kinds of muscle action.


1. Maximal Strength: the biggest amount of weight you can lift in a single repetition. For example, in a squat at the gym.

2. Rapid Strength: the ability to generate a strength impulse in a short period of time. For example, very fast punch or displacement. Rapid Strength is divided into the following sub-types:

a. Explosive Strength: the fastest impulse our neuromuscular system can produce in a short period of time.

Here, I’m not necessarily talking about actual movement, but neuromuscular impulse; in other words, if you try to push a wall as fast as you can, you’re not able to move it but you activate your muscles in a very fast way. That’s Explosive Strength.

You’ve different kinds of Explosive Strength, if you try to overcome less or more than 25% of your Maximal Strength.

b. Muscle Power: Force X Velocity. It demands a fast muscle contraction and movement.

With low resistance we’re talking more about the Velocity dimension of Power (a simple punch, kick, or displacement with your body-weight only); but if you have to throw a heavy training partner that resists, we’re now talking about the Force dimension of Power.
To be called Muscle Power it must have movement (in contrast to Explosive Strength)

3. Reactive Strength: the great majority of Karate movements are not pure and isolated muscular actions. Reactive Strength manifests itself in Stretch-Shortening Cycles of the muscles.

a. Karate Application: we’re talking about Kumite displacements from a hopping Kamae or when you quickly pullback your arm before a technique in Kata (for example, the Shuto-uke in Chatanyara Kushanku or Pinan Shodan, where you pull the arm back before executing the defense – this gives you much more power).

4. Endurance Strength: the ability to produce strength for a medium or long period of time, while keeping the muscular performance at a good level (resistance to fatigue).

a. Karate Application: to perform longer Katas like Suparinpei or Chatan Yara Kushanku or to maintain a good level of fighting for longer periods, you’ll need Endurance Strength.


Dynamic Muscle Actions

1. Concentric Actions: when the muscle contraction is higher than the resistance that it has to overcome, voluntary movement occurs. This is the main contraction type used by your muscles to produce movement and it’s responsible for the acceleration.

a. Karate Application: the knee’s raise and the leg extension in a Mae-Geri or when you move in Zenkutsu-dachi from a static position.

2. Eccentric Actions: when the muscle contraction is lower than the resistance that it has to overcome. The muscles are producing strength, trying to shorten, but what really happens is an extension of that muscle. This kind of action is produced by external forces and is relevant for movement braking and damping.

a. Karate Application:
* when an opponent unbalances you trying to make a successful throw and you can avoid it by firmly braking with your foot on the ground;
* when you must change your body displacement direction to avoid a counterattack in Kumite;
* when you make a fast-displacement in Kata and need to stop in a steady, stable, and strong stance.

Static Muscle Actions

1. Isometric Actions: when the muscle contraction is similar to the resistance. This happens when you have your muscles tense but there is no movement.

a. Karate Application: the maintenance of a Shiko-dachi or any other leg stance while executing Te Waza or Uke Waza Kihon.

I hope this was useful for you to understand better how you and your athletes’ body works, so you can plan the best exercises.

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