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sábado, 30 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 7).

You can see today the result of some analysis using impacts and its relationship with different variables as the space of interaction used in the specific training tasks, type of task (small sided soccer or possession game), duration of the task interval (time), number of players of the small sided games, and also the relationship of the impacts with the player profile (speed and acceleration, endurance, age and weight).
All this data comes from different specific tasks and friendly games performed by a Spanish professional soccer team that played in first division during the 2007-08 session.
Enjoy it,


miércoles, 27 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 6).

Usually, impacts coming from triaxial accelerometer (A3X) data is used in different ways: the most simple is just to count the total number of impacts over a defined threshold (between 2 and 5 G, that is number of times the value of the Gravity, around 9'8 m/s/s), or using some arbitrary units to give a different value to each impact; that means that lower impacts has less "weight" on the load the player is experiencing, and higher impacts has much more "weight".
But I want to comment another parameter that I have been using for a long time. This parameter is the relationship between the number of impacts over 5G and the number of accelerations demonstrated by the player (as typically the impacts are mainly related with the decelerations, and acceleration and deceleration should be related ... (this is not exactly like this, but in 2006 - 2007 there was no possibility to use deceleration ... and sometimes you can see higher impacts when accelerating ...).

You will see some data obtained from friendly games of professional soccer players, comparing first and second time, and also depending on the positional roles.

Enjoy it,

sábado, 23 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 5).

And we arrive to the impacts and triaxial accelerometer (A3X) use for the control of loads in soccer training and competition, and also other sports activity.
In this case, we have to know that actually, the main GPS systems developed for their use in professional team sports, integrate a triaxial accelerometer (A3X) that works at 100 Hz. This important part of the system has been used in different ways during this years in order to control the load directly or indirectly, and also we have to know that the algorithms used for the measuring of the load that is being experienced by the player has also changed.
Some years ago, this algorithms weren't known, but today this trend is changing.
As this issue is nowadays changing and is being developed because the use of A3X could be a powerful tool for detecting specific movements and the loads associated, I just give you some info about the initial use of it, and also some results of the particular use I have been doing during this years.
Remember that all this stuff is in constant movement, what means that the content is sure evolving ...

Hope you enjoy this introduction about A3X use.


miércoles, 20 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 4).

Some more typical and interesting characteristics used for the analysis of accelerations are shown today.
In line with previous posts, you will see data obtained from a professional soccer player during a friendly game. Some of this data can be obtained directly from the software, but some other must be acquired via exporting raw data to Excel (or similar soft) and applying some algorithms, or just doing yourself ..., so it will take some more time ...

Enjoy,


sábado, 16 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 3.2).

In today post, I just complete the information related with the sprint demonstrated by a professional soccer player during a friendly game, in which we can observe an initial speed of 9,6 km/h when the player starts his acceleration.
You will see the trajectory and also a short cut of the video of the game in which we see this action.
Enjoy ans stay tuned!


miércoles, 13 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 3.1).

In today post, I want to share with you how this relationship between the initial speed and the maximum acceleration achieved by a professional soccer player during a friendly game can be showed by a GPS system software.
We have to be aware about the possibility that different softwares detect in a different way this relationship.
So I have just taken an sprint action of a professional soccer player during a friendly game in which the acceleration is performed with an initial speed of around 9-10 km/h. You will see some data related to this action: speed, acceleration, triaxial accelerometer data and ... the position on the pitch and the video images, but this will be in the next post, so stay tuned!


sábado, 9 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 3).

Following the last post on the blog, today we will talk something more about the relationship between the initial speed (when starting an acceleration) and the absolute value of the acceleration performed.
I show you some data obtained during some training sessions of an amateur veteran soccer player, in which you can see some of the characteristics of this relationship.

Stay tunned!


miércoles, 6 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 2).

Today I'm going to try to explain some basic considerations in the analysis of the accelerations. This considerations are an essential issue for understanding correctly some of the data we are using when controlling soccer games and training loads.

Basically, as you sure know, when analyzing accelerations demonstrated by soccer players, we must use not only the absolute value of the acceleration shown in the sprint, but also the initial speed at which the player was running when starting the sprint (so the acceleration).
Sometimes this initial speed is near to 0 km/h (so the player is standing or just walking), but the most of the sprints players do when playing a game are demonstrated with a certain initial speed (so running).
Also, we don't have to forget that the sort of data we are using in this type of analysis depends directly on the way the software detects and consider there has been an acceleration ...and as there is not a "gold standard", any comparison must be done carefully.

Stay tunned!


domingo, 3 de marzo de 2013

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 2 (part 1).

Let's go for the second level of analysis of the physical demonstration of professional soccer players.
It's important to remember that this is just a way of explaining the different approaches and level of analysis, and I just want to transmit that there exist these different ways and different parameters to study the same physical demonstration.

In this second level, we put the emphasis on the analysis of accelerations and some the important characteristics that should be known.

Hope you enjoy.