Eccentric force in traditional exercises (part 1).
These week a colleague that works in a Spanish first division team, phone me in order to consult the relationship between one of the variables that a GPS System (that includes a triaxial accelerometer A3X), that is the total number of impacts (number of times that the A3X get's a value higher than a threshold value previously defined), and some type of injuries (bone fractures).
Apart from the importance of knowing the limitations that each short of technology has, and the limitations related to the way we use it, he has wake me up an old issue that last years has been rising up in soccer conditioning world because of it's relationship with the production and prevention of some injuries: the eccentric force.

So I start today a set of audiovideos in which I'll show you some data obtained years ago in order to clarify some concepts sometimes forgotten about how the force is applied in the "eccentric" phase of a movement, in this case in traditional exercises, starting with some data get by a A3X in some soccer specific movements (sprint, change of direction, deceleration).

You must know that the system used to get this data is a linear encoder working at 1000 hz, with software Isocontrol 6.0 (2012). All the exercises has been performed by the same player (veteran and with good experience in strength training).
Enjoy,

Relationship between maximal acceleration in a sprint and specific horizontal strength in professional soccer players.
This data have been collected with a GPS system of 1 hz for GPS speed and 100 hz for triaxial accelerometer acceleration.
As you know (at least in a more simplistic approach ...) in a sprint, the value of the strength applied should depend directly on the acceleration demonstrated, specially the horizontal acceleration applied by, in this case, the soccer players, as F=m*a, where "F" is force, "m" is mass and "a" is acceleration, so for a sprint (horizontal F = m* horizontal a).
Few studies has showed us the relationship between speed and horizontal relative force applied, and also this relationship with the possibility of hamstrings injuries. Here I show you the relationship I have founded between maximal acceleration in a sprint with the value of the horizontal acceleration applied by soccer players in their first steps.
Conclusion: nothing new but most of time forgot, the importance of highlight the use of different means and methods specifically oriented to the development of specific horizontal acceleration for soccer players, based on the use of EXPLOSIVE longer steps.
Enjoy,

Evolution of external load and it's relationship with competitive results.
After the previous two posts based on the control and evolution of external load, I present you this new audiovideo in which you can find the relationship between general explosive strength data (number of sets per week), specific explosive strength data (average maximal acceleration value of the team per month), and the special "bonus": their relationship with the number of points won in matches per month.
It's specially important to avoid a general and more simplistic thinking that in any condition the results will be the same that this we have had in this team. In other post I will show you other data analysis in which you will be able to understand widely what and why I'm saying that.
Just follow and enjoy,

Evolution of external load during the preseason (part 2).
This is the continuation of the audiovideo about the evolution during the preseason, in which you can see the relationship between the volume of variables used actually (distance, high intensity distance and time at high intensity of HR) with the volume of time used in tasks with or without ball depending on the exertion demonstrated in them (for further comprehension see the post about "Intermittence and metabolic power".
Enjoy,




Evolution de la charge externe au cours de la pré-saison (partie 2).
Il s'agit de la continuation de la audiovidéo sur l'évolution au cours de la pré-saison, dans lequel vous pouvez voir la relation entre le volume des variables utilisées effectivement (distance, la distance à haute intensité et de temps à haute intensité de FC) avec le volume de temps utilisé dans les tâches avec ou sans ballon en fonction de l'effort démontré en elles (pour mieux comprendre, voir le post sur "l'intermittence et la puissance métabolique».
Profitez-en,

Evolution of external load during the preseason.
Today I want to show you some data related with the quantification of the external load of spanish first division soccer team, where we'll see that maybe some traditional concepts associated with volume and intensity doesn't represent really what we think (so better we should change the approach ...).
This time the audiovideo (first part) it's in french.
Enjoy,


Evolution de la charge externe au cours de la pré-saison.
Aujourd'hui, je veux vous montrer quelques données relatives à la quantification de la charge externe d'une équipe de première division espagnole de football, où nous verrons que peut-être certains concepts traditionnels associés avec le volume et l'intensité ne représentent pas vraiment ce que nous pensons (alors ça serait mieux changer l'approche ...).
Cette fois, le audiovidéo (première partie), il est en français.
Profitez-en,

Intermittence and metabolic power in small sided and possession games (part 4 of 4).
In this last part I show you some unknown data of the metabolic power demonstrated by two players in different specific task (small sided games and possession games) depending on the number of players participating, and the tendency of this value and its comparison with previous data.
I hope you will find it as interesting as me in order to relate it to different models of periodization and to help in the process of programming your training sessions.
Enjoy,

Intermittence and metabolic power in small sided and possession games (part 3 of 4).

In this 3th part you will find the essence of the analysis of the conditional demonstration on the specific task (small sided games mainly) based on the specificity of the intermittence.

With this information you will understand better the relationship of that conditional demonstration based on the number of players that are participating on the task, in order to use it to organize your training sessions and also your own model of periodization.

Enjoy,