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jueves, 10 de abril de 2014

Horizontal mech power: future & A3X?

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 8 (part 5).

Not too much to say in this posts: just recapitulation of what we have seen about horizontal mechanical power, and some thoughts of what we possibly will see in the future if triaxial accelerometer data is finally integrated with speed data in order to use it as a monitoring parameter.

Stay tuned!


jueves, 3 de abril de 2014

Bezodis, Gaudino & Samozino approaches to horizontal mechanical power

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 8 (part 4).

We continue with the approaches used by Bezodis et al. 2008, Gaudino et al. 2012, and Samozino et al. 2013, for the calculus of the horizontal mechanical power demonstrated by different athletes, some of them soccer players.
The basic characteristic of this approaches is that they put more "weight" to the acceleration demonstrated by the athlete, and that means, as you will see in the graphics presented today, that when the player shows a more or less constant speed (not frequent but sometimes happens dependent on the task or phase of the game ...) he is not applying horizontal mechanical power.
See it and take your own conclusion ... and share!

Enjoy,





jueves, 27 de marzo de 2014

Cavagna & Gray approaches to horizontal mechanical power

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 8 (part 3).

Let's see what happens when applying the different approaches to the same action (in this case a CoD sprint of 5+5+16+16m), paying special attention to the shape of the horizontal mechanical power and how it is related with speed and acceleration.
Today we will start with the approaches of Cavagna and Gray.

Hope you enjoy,



jueves, 20 de marzo de 2014

Horizontal mechanical power approaches

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 8 (part 2).

After analyze some (far from all ...) papers about different approaches proposed for the analysis of the horizontal mechanical power, I present you just some of them that could be applied for this sort of analysis.
In this sense, the fact of using the horizontal mechanical power approach represents (under my view) another step forward for analyzing the conditional demonstration of soccer players (and also other sports ...) during games and trainings.

Using one or another approach should facilitate the analysis and interpretation of the mechanical load related not only with speed, but specially with accelerations and decelerations, in which their relationship with the velocity alters the mechanical power experienced by the player.
An acceleration performed with a velocity of 5 km/h represent a different load than other performed with a velocity of 15 km/h, and the same is valid for decelerations. So not only the absolute value is important, but also the velocity associated with it.

Some of the approaches have been used for their application with soccer players, others no. Lets see their essential differences.

Hope you find it interesting.

martes, 11 de marzo de 2014

Horizontal mechanical power intro

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 8 (part 1).

After a too long break due to professional work density ... we continue with the next level of of analysis and approaches of the physical demonstration of professional soccer players.

In this new level, we introduce the horizontal mechanical power approach. Nowadays, we see how sport science and professionals are trying to develop their own approaches in order to analyze the activity of players during training and games, using different metrics and ways of using them ...
Using the proposed intermittent approach, the selection of the basic parameter to obtain the intensity of the player's activity is a key factor. This intensity has been traditionally analyzed using HR first, then speed, impacts (from triaxial accelerometer data) and lately metabolic power approach. As the HR gives us just the cardiovascular intensity, related of course with the metabolic exertion, and the speed don't take in account the great importance that acceleration has, it seems that the metabolic power approach offer a step forward for measuring the intensity of the player (using speed and acceleration to obtain a metabolic measure), knowing that there exist some points that could be argued against.

But analyzing the actions that the players perform during games and training sessions, and also relating them to some sort of injuries and overloads they suffer, we should introduce some sort of metric that when detecting actions, it takes into account the decelerations produced by the players.
As we have seen in some previous posts, using metabolic power data for detecting actions, let the deceleration out of the action phase. Logical, done that it measures the metabolic intensity, that in decelerations are low. But we all know that decelerations are an important source of mechanic overload (muscle, tendons and articulations ...), and frequently related with some injuries.
Appart from that, we have been analyzing the importance of the relationship between speed and acc-dec value demonstrated by the player in order to correctly "weight" the intensity of this parts of an sprint, that actually it's not been taken in account yet ...

So with all this in mind, we introduce today (and in the next posts) some info about the horizontal mechanical power approach, authors, and later some graphics.

Hope you enjoy,

jueves, 20 de febrero de 2014

Amateur vs professional collective conditional exertion in soccer games

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 7 (part 9).

And following the last post, in which we analyzed the collective conditional demonstration of professional soccer players during a pre-season game, based on the metabolic power approach, today I want to present you that same analysis, but done during an amateur in-season soccer game (a derby!).
Fortunately, players and staff agreed to go on with the game monitoring, in order to get some insight of their conditional performance, and how to use this information to modify some methodological characteristics of their training sessions.

Remember that in this video you are going to see the data of the first time of each game (am-pro).

After the analysis, you will see that, in this case, the basic difference in the collective conditional demonstration between amateur and professional soccer players is the interval time during which they are able to maintain a higher collective conditional exertion, that in professional soccer players is higher as an average.
Also, and directly related with it, professional soccer players show a higher amount of total time of higher collective conditional exertion during a game.

How to use this data: this is the key question! My proposal is that it depends on the target of the specific task used on training session: if the main target is developing the conditional structure of the players, then probably is more interesting to use lower interval durations, while if the main target is on tactical development, then probably is better to use longer interval duration on the specific tasks ...

There are more aspects to handle for a better use in the specific tasks programming, but this is another issue ...

Hope you enjoy!

martes, 11 de febrero de 2014

Collective conditional exertion in professional soccer games

Approaches and level of analysis of the physical demonstration of professional soccer players. Level 7 (part 8).

After having posted about some approaches for the individual conditional exertion analysis during soccer games, in the next two posts I propose you to see some data related to the collective conditional demonstration during soccer games.
In this post, we'll see this analysis done with data from a professional friendly pre-season soccer game, monitored with 1Hz GPS System, and using exported raw data to do the analysis.

Hope you enjoy,