Size Matters: Because Physics!

Posted: October 24, 2017 by Jonathan Fader in Krav Maga Instruction, Uncategorized
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Krav Maga teaches aggression which allows you to over come your opponents no matter the size? Sound familer? Or how about this. Learning Brazilian Jiu Jitsu will allow smaller people to beat bigger people every time?

While partially true statements they only show part of a much larger picture. Believing either of those two statements out right can be dangerous. Like everything else, we must approach it with realistic eyes and not beliefs that baseless in reality.

So let’s start with the basics.

Time for some Newtonian Physics! Which I am by no means in any way shape or form an expert on considering I didn’t even take high school physics and yet some how came to understand through practising martial arts. Yay Practical experience!

Newtons Second Law: In an inertial reference frame, the vector sum of the forces F on an object is equal to the mass m of that object multiplied by the acceleration a of the object: F = ma.

Newtons Third Law: When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

So what does this mean? It means, there is a reason there are weight classes in professional fighting. Of course, if a person who is 100lbs has 5 black belts and has been training for 30 years, they will most likely win a fight against a person who is 200lbs with 0 fighting experience.

However, an individual who is heavier and has more mass can because of physics exert far more force with relatively less energy. If a person who is 100lbs hits a person twice their size, they will have to hit considerably harder to do significant damage compared to the opposite. For them, the larger opponent with out even doing anything is exerting and force back simply by having mass.

This is the reason we target soft targets in Krav Maga, like the groin, the throat and the eyes. By using Biological weak spots, we are not ignoring physics just finding a “cheat” around it.

However, in training, we should never intentionally be trying to hurt our training partners. As such, we should always take physics into account to avoid mass related injuries and unnecessary head trauma like concussions.

In Sparring, we often tell our students to go 10% as we want them to work on range, speed, technique, movement etc. rather than trying to kill each other every time. This means that a 200lbs person’s 10% when sparring a person who is 100lbs also going 10% they are not equal in force due to their mass and size difference. So really to encourage a healthy training environment the larger person might actually need to go 1% of their power

So what does this mean in real street situations? It means that just because you have training and skill that aggression and speed alone cannot always overcome larger opponents. And believing anything to the contrary can be dangerous.

Imagine a scenario where you are 100lbs, and for whatever reason, you cannot use the biological cheat to down your opponent, it will be a momentous feat if you can overcome a much larger opponent with strikes alone. While not impossible it may take far too long for practical self defense.

It also means that for smaller practitioners it is probably a good idea to cross train Krav Maga or other forms of practical self defense training with some kind of Grappling. I recommend BJJ of course, but other types are also acceptable. This is because with little effort a much larger opponent will have an easier time putting you on the ground either intentionally with skill and technique or unintentionally with simple physics.

So remember, because of the laws of physics size DOES matter in hand to hand combat situations. The smaller you are, the more you need to train to raise your overall skill level to cheat physics safely.

Don’t feel bad though, being smaller or shorter as a human I have heard means you get to live longer as your heart has to work less against gravity through out its life. (Fact Check Please) Though, even if its proven wrong I will still like to beleive it to justify being short…

So remember, No Groin, NO KRAV MAGA!