Frans Bosch on agility, perception, and understanding errors

Agree with his methods or not, few coaches have forced us to rethink how we prepare athletes as Frans Bosch has over the last five years. The publication of Strength Training and Coordination: An Integrative Approach started a conversation about how motor learning concepts can be brought into the weight room.

Next week, his latest book Anatomy of Agility: Movement Analysis in Sport (available for preorder in the HMMR Store) will be released and it dives deeper into some of the topics he raised in his last book. He looks further into topics concepts as constraints, self-organization, self-stability and attractors. Then he continues to define specific attractors for training agility to translate theory to practice.

Earlier this month we had the chance to sit down with Bosch and ask him some questions about the upcoming book. The result is a two-part interview. In part one below we look at the role of perception in agility, how to eliminate errors, developing independent athletes, and quantifying progress. In part two, we look more at attractors, connecting training to context, and how this impacts other general training concepts.

The role of perception in agility

MB: I wanted to start by looking a little at the sensory aspects. Reaction and anticipation are key parts of agility and you even mentioned in the introduction to your book you might get criticism for not going into these sensory aspects that much. How big of a role do you see from the sensory aspects? And is it something you can just layer back on top of the other aspects you discuss in the book? Or how do they fit together?

Bosch: The way science is looking at this is changing right no­w and Rob Gray is one of the stakeholders in that. Before it was very much thought that perception leads to action: that you have to perceive what is going on before you can act. Reactive agility training is based on that. Now people realize that there is also an action to perception sequence. In other words, your actions yield perception and if the action is poor you won’t perceive. For example, if you are standing still you will not yield the same information you get when you are moving. If your body posture and your tension is such that you can not execute a movement solution anyway, then you will not perceive that solution any more. If you cannot change your running angle to run into a gap between opponents, you will not perceive the openness of that space anymore

Perception and action are not isolated such that one is a slave to the other. Movement is not the slave of perception and perception is not the salve to movement. How much you can perceive depends on how you move as well. The perception-action cycle is actually a perception-action-action-perception cycle.

If you look at it like that, you can see the value of looking at the movement side of agility. If you have better technique, you will probably perceive and see the options better.

MB: Or even simple things like keeping the head still is one of the attractors you discuss in the book. Having a stable head will have a huge impact on perception.

Bosch: If you go up and down in the vertical direction each time you shift, about 120ms of information is gone. Also if you have no body tension, you cannot react properly.

I understand people that emphasize the reactive part of it. But if you look at sports and how much of this reactive training that is going on in games and things on the field, it is quite a bit. But the movement side is very often left behind and the filter for perception is not improved enough. 

MB: As you say, the book is focusing more on the action-perception side of the cycle. Do you feel that the perception-action side then is in most cases adequately covered by the field sessions for the sport?

Bosch: Yes, but a good coach needs to make sure that information is optimal and rich in the field session. If you play the same opponent over and over in training you will pick up cues that are very individual to that player. But when you play a game that player is on your side and you have someone else to play against, so you didn’t learn the general rules of perception.

You need to be doing things like changing the teams all the time so players acquire the general rules of learning someone’s body position. This can be done in games, but it must be optimized.

MB: We also tend to think about sensory as just the visual aspect, but we sense in many ways. Just knowing your body and where we are in space is a complex topic and we have to develop this as well.  

Bosch: The last chapter of the book talks about what the intrinsic learning capacity of a sport is. Many sports like tennis and basketball teach you to move properly for free. But there are other sports that don’t teach you much, or even give you a stimulus to move worse and worse. For example, soccer is the game of losing the ball. Handling the ball is so difficult that handling your own body has to be set aside; the body can’t prioritize two things at the same time. You see in these sports the ball handling skills are better than the body handling skills and the sport is not giving you the intrinsic learning for free. If you do not augment training with agility patterns set aside from playing games, you probably will never improve movement and the filter for perceiving at a high level.

Understanding errors

MB: You mention that in soccer there are lots of errors. On your recent interview with the Science for Sport Podcast you made an interesting statement: “If someone makes an error, don’t correct it, make it worse.” Can you explain a little more about what you meant there? This is counterintuitive and many coaches will be scared that this approach will result in doing more harm than good.

Bosch: The main characteristic of an error is that it is a very stable movement pattern. The idea that something is an error because it is unstable is not true. Errors can be extremely stable and if you want to correct errors the stability of the error is the main thing you want to focus on.

The normal way of working is that you have an error and you teach someone an alternative and you hope it pushes the error away. That doesn’t work very well. There is a very simple rule: the older stable pattern stays.

What you need to do is to put the error in an environment where it is unstable and it collapses and the body does not trust the error anymore and it will go for something else. That is an approach that is very important in getting rid of errors.

MB: So rather than slowly push the error towards what you want, you try to break it up and destabilize it and start from scratch again to get the body to revert to reflexes or other attractors. 

Bosch: Yes. Coaches just need to understand the stability of the error is the big problem. The body always wants to go back to that since it feels stable, but it is not effective in the given situation you are in. You need to get rid of it if you want to find something that is also stable but more applicable in the situation you are in.

Developing independent athletes

MB: I had the opportunity to watch you coach at the Welsh Rugby training camp in Switzerland last year. What I found interesting was that during breakout sessions you have a clear idea of what you wanted to do, but no plan for sets and reps and the athletes had a lot of input on how the session went. Their own feedback was key. For coaches with less experience with this approach to training, that might be harder. Do you have any tips for them?

Bosch: The main thing you have to deal in working with athletes is individuality. Each one has an individual landscape in which he designs his movement. There are hierarchies, conflicts, all that in there. You have to understand the individual athlete: this guy might lose body tension very quickly in difficult situations, this guy might have a natural hip lock that can rescue him in certain situations. If you have this, you have access to where you should go with this player.

The second notion you have to have is that the main information processed by the athlete is not your information; it is their own information. If you try to take their information out and replace it with your information, you just push their own processing away. If you work with an athlete for a long time, it is always very valuable to go to a learning process where they can make decisions for themselves about these things: that they need a lighter or heavier bar, this doesn’t feel explosive compared to the field, and so on.

This is something that happened with Welsh Rugby. I would have several bars to choose from and they could choose which one, not because they were lazy but because they had a picture in their head about how the movement is. They very quickly became better and better at that.

MB: You could see that most with athletes like George North. He has worked with you a long time and was also one of the most independent. On the HMMR Podcast recently we also talked with Gonzaga University basketball strength coach Travis Knight. He has been to your seminar and implemented some of your methods. Another benefit he sees of this approach is that athletes take more ownership in the program and therefore it becomes more effective once they believe in it.

Bosch: It is a field the Gabriele Wulf is going into. If athletes choose the exercises themselves you get better results than when the coach chooses them.

Quantifying progress

MB: One criticism of your approach to strength and conditioning, as opposed to a more classical approach, is that you can’t easily quantify progress in movement like you can with a back squat. Do you have any methods you use here, or any tips for coaches in this area?

Bosch: That’s the hardest part, especially at a higher level transfer is hard to pinpoint. Go to a Major League Baseball spring training and try to figure out what exercises they are doing that distinguish minor league level from major league level. You won’t find them. It is difficult to analyze at an elite level.

We had a machine for pole vaulters in Holland where they were hoisted up into the air by a counterweight and they could do all their actions on the pole. A good friend of mine is one the best track and field coaches I’ve ever met and he said this is very good until you jump 5.40m. Why? Because then how you apply strength qualities becomes more relevant. Then once you jump 5.70m it has an adverse effect as then rhythm becomes more important and on this machine the rhythm is different. A pole flexes, but the machine just pulls you up.

What you see therefore at a higher level is that what works for sub-elite might have a negative effect for the elite because these things are hard to quantify. Very often we have to acknowledge that it is just random luck that transfer happens.

MB: So then coaches just need to experiment and see when they get lucky?

Bosch: And understand where the weak points of an athlete are. Understand where he slips back into something that loses stability in certain areas quickly. It’s a very refined process and in a refined process something simple like sets and reps and mechanistic transfer don’t do anything.

MB: How much do you rely on looking at game film to analyze movement, versus what you see in training?

Bosch: I’ve started to work more from games and matches to see where their movement patters are. What you see all the time is that athletes are doing their S&C and coordination on the pitch and then when they play the sport it is completely different. You need to understand what is happening in the sport itself and maybe get some pointers from there that you can work on. If these are solid attractors that you work on, they will emerge again in their sport.

MB: Stay tuned for part two, where we look more at attractors, connecting training to context, and how this impacts other general training concepts.