Mastering Jiu Jitsu with Momentum

When you think about momentum do you think about speed? Most people do. And, although this isn’t wrong, let’s think about it in a different way. Let’s analyze how momentum can be forced, applied, and given. We can think about these three kinds of momentum as stages we pass through in our developmental as Brazilian Jiu Jitsu or Mixed Martial Arts practitioners.

The unfortunate thing for most people who enter the martial arts arena, is that they never learn the essence of true momentum, or the advantage gained by using it properly. It is my goal to share the tools and knowledge needed to understand the importance of momentum as it applies to BJJ. Understanding momentum can help move your thinking from white belt to black belt levels.

Bully Jitsu
Momentum changes if we force our opponent to change directions. I call this Bully Jitsu. Most commonly this is a push or a pull which causes someone to change direction or velocity due to the force of energy upon contact. We see this all of the time on the mat when guys go for takedowns or sweeps.

An easy way to think of Bully Jitsu is to imagine two bodies colliding head on. The winner is usually the bigger or faster one. So in this battle it doesn’t pay to be the smaller, slower guy. It doesn’t take a whiz to figure out why a bigger guy can push a smaller one around, but let’s take a closer look at how physics is applied so we can build our knowledge for further analysis.

For our example let’s assume that both athletes are identical in mass and size. And for the sake of simplicity, we’ll say that energy isn’t absorbed from the collision. What does high school physics tell us about two guys smashing into each other?

Figure 1
Figure 1 above shows us that if person A runs very fast and smashes into person B, who is running at the same speed, they collide and bounce off each other the same speed they were going. We see this a lot in the gym, especially with white belts who try to muscle through things.

But what happens if we put a bigger guy against a someone half his size? The equation would read something like this. Person A and Person B are driving for the takedown. Person A is twice as heavy as Person B. After colliding into each other, Person B bounces backwards almost 2 times faster than the bigger guy (B2). Again, bad for the little guy. Most of you reading this have probably experienced being pushed around by someone 2 times your size.

Figure 2
When this happens you also know that it is probably you that lands on your back. In fact,
according to physical laws, you’ll bounce off about 2 times the velocity you were going and the
bigger guy hardly feels the effects. This is due to the transfer of energy and mass from the
This is exactly what we see day in and day out in the gym: two guys going at it like
bighorn sheep. They continue to bang heads until one finally succumbs to the other. Typically,
the larger you are the better you’ll fair in the big horn sheep combat match. Not unlike the BJJ
mat or cage match. (What’s more, these are the guys who gas-out quickly because of their
relentless use of muscle and oxygen.)  

Playground Jitsu
As you get further into BJJ you should acquire awareness of the difference between easy movements and difficult ones. I’m not talking about white belt versus black belt movements but ones that flow smoothly versus those that take extra work getting done- like Bully Jitsu moves. Arriving at this stage in the game means learning to avoid, at least in part, the head on collision game. Instead, you start to realize when to apply a move at the appropriate time and catch your opponent off guard. I call this stage Playground Jitsu.


At the playground we used to get behind our friends when they weren’t looking and have someone push them over us causing them to fall. Remember those tricks! In BJJ you can do this by simply catching your opponent off guard. By the time you reach mid-blue belt range, you should be showing signs of this proficiency at the expense of your opponent. Let me show you how it works. 

Say you are on the bottom position of the guard and are wanting to execute a hip sweep. You feel some resistance from your opponent as he pushes on your hips and torso to keep you in place. So to keep from being a Bully, you decide to wait until your opponent relaxes for a second. At the very moment you feel your opponent relax you sit up and execute a perfect hip sweep ending up in the mounted position. “How easy was that?”. . . you ask yourself. Too easy! The reason why it was effortless takes us back to physics.

Figure 3
The equation looks like this. You (Person A) are on the bottom position of the guard and want to execute a hip sweep. You feel some resistance from your opponent (Person B) as he is pushes on your hips and torso to keep you in place. You decide to wait (important) until your opponent relaxes (V0) for a second. At the very moment you feel your opponent relax (V0) you sit up and execute a perfect hip sweep ending up in the mounted position.

Why is this important to know? I guess if you want to be a bully then it isn’t important. But if you want to use less force to accomplish the same task then it is critical to learn! Check it out. If you can push, pull, or collide with your opponent who is momentarily at a stand still you’ll get him to move at the velocity you started out at. Now here’s the great news. If your opponent is bigger than you and you execute a hip sweep while he is at a stand still you will still get him to sweep- with no additional effort! Bravo for the smaller guy!

Black Belt Jitsu
The third level is without question the most important one. Here is where we are given control of momentum by using our opponent’s directional patterns. This is free impetus. Impetus is the force or energy with which a body moves. As a white belt, or even higher, you are so concerned with enforcing your way and will upon your opponent (i.e. Bully Jitsu) that you usually neglect learning this critical aspect of your game. Likewise, as a purple belt, knowing when to catch your opponent off guard (i.e. Playground Jitsu) may be as far as you’ve progressed.


But to move to the next level in your game you need to learn the lesson of free impetus. I call this level Black Belt Jitsu. This momentum is given to us. Have you ever had a sweep or takedown feel really easy and wonder why? I mean almost like the opponent fell right into it or gave it to you. It’s the same move you’ve done a ton of times but something just seemed smooth, clean, and easy.


Black Belt Jitsu thinkers should be concerned with how to replicate freely given momentum. It’s that simple. So check it out. Person A and B are sparring for a takedown. Person B leans in, applying pressure to Person A. Instead of pushing directly back into the pressure (resulting in a stalemate with no motion) Person A applies pressure at an angle. Person B absorbs all the force and is now moving almost twice as fast as he was, while Person A stays almost still. The same principle can be applied in guard. That’s free impetus-- Black Belt Jitsu!

Figure 4
Learning when to react to momentum swings requires awareness that comes with years of
training and good teaching. It doesn’t necessarily come with a belt color because some find ways around learning it and still move up the ranks. These individuals are athletic and use natural abilities to win matches. However, the day that you have a Black Belt Jitsu moment your game will never be the same.  

Remember to try to avoid head on collisions. Instead, consider learning to wait until your opponent moves and go with the flow. It isn’t hard to see the advantage you could have while understanding and using free momentum. It’s remarkable! This is truly what separates the the good guys from the great guys. And you don’t have to be a black belt to achieve it.


Wally Holem is BJJ black belt and teaches at the Carlson Gracie Jiu Jitsu Club in Mishawaka Indiana. He is also a Strength and Conditioning Coach at Bethel College and holds a Masters Degree in Exercise Science. He can be contacted at: 

Note: The equations are intended to illustrate the concepts discussed, and are not exact. Physics geeks need not lecture on newtonian mechanics!