top of page
  • Daniel Kamenetzky


The access that a young player might have to a competitive professional life depends primarily on the education/training received at his/her Soccer Academy. One of the most important methodological aspects of the program in any Academy offering involves the permanent understanding of each player’s needs and limitations. This is achieved through the scientific model of describing, interpreting, and designing specifically for each player.

Soccer Academies that lack objective processes of player evaluation, data integration, and information generation will immediately decrease its efficiency (the number of promotions to the professional level) and will provide a lower quality service to their customers: players, parents, fans, investors, etc.

Data collection and analysis during the initial stages of a soccer player's development is very important to identify individual and team needs. Also, to avoid training strategies that can conflict with the biological developmental process. It should guide always the training model toward high levels of performance, which will be permanently corroborated through a scientific model of control.

We learn in every conference and coaching class that a young player is not an adult and that we need to treat him/her individually while preventing possible psychological and/or physical harm. What rarely the same presenters explain is “what a young athlete is”, “how do they look like,” and “what is different in relation to adults.”

It is not enough to know that young players are different from adults.

We need to know how and how much different they are.

Following the previous article, I’m going to describe some aspects where young players are different from adult players. I’m going to show how important is to use and integrate data to find “who” are we working with, and what limitations do they have?

From the data collected by the Chivas Professional Football Club of Mexico in several categories (link to article), I am here to analyze two biological variables that are critical to life and football performance: muscle and adipose masses. Both are directly dependent on biological changes and training design.

Watching the graph below and without any initial numerical analysis, it immediately will catch your eyes because:

1. The muscular mass for all positions is similar in the 4th and 3rd divisions and it is increasing “significantly” from the 3rd to the 2nd division.

2. For each field position, the fat mass remained almost constant in all three categories.

There are several maturity and training reasons for these observations. We should remember that we are talking about male players because female players will have important biological considerations that will affect training strategies in different ways.

Let’s analyze what could have happened at Chivas to obtain those anthropometric values and the implications for performance in the field and for training design:

1. The persistent values of adipose tissue across divisions show that during the Academy years the system for utilization of fat as a source of energy has not been well-developed. This limitation decreases the endurance capacity by reducing the mitochondrial energy production, and by making the player carrying more body mass than needed. Both will accelerate the onset of fatigue and therefore reduce accuracy, technical ability, decision-making, and conditional performance.

2. The high content of adipose tissue in competitive athletes compared to the general population (see the previous article) is also an indication of poor nutritional behavior. The relationship between total calories intake, the proportionality of sources of energy intake (fat, carbohydrates, and proteins) and the proportionality of training intensities are clearly not adjusted for the competitive players’ needs.

3. The increment in muscular mass from 16 to 20 years old is most probably related to the maturation of the sexual hormonal system. Its increment in power (capacity of production of largely testosterone per unit of time) is critical for muscle mass growth. If there was any resistance training in the 4th and 3rd division clearly did not generate any difference in muscle growth. This fact is a powerful example of why the utilization of weightlifting training before the presence of testosterone has little or no effect on the augmentation of muscle mass while increasing the risk of injuries.

4. Considering the amount of adipose tissue in each field position and division (refer to the previous post), we can estimate that the physiological training of the newly obtained muscular mass in the 2nd division is non-specific for the game’s requirements. Clearly, the aerobic capacity of the muscular mass is physiologically limited for the consumption of high quantities of fat. This situation is generally related to the lack of endurance stimulation, allowing the adipose stores to remain the same or even increasing. In the graph, the defensive midfielders and forwards have increments in adipose stores from 3rd to 2nd division when we should be seen an opposite trend (in the next few articles you will see each position’s characteristics more specifically and the implications for professional performance).

5. The average proportion of muscle mass for total body mass in all 2nd Division positions is below 50% (see graph’s upper rectangle: “Muscle % of total Body Mass”). An international soccer player is expected to have approximately 55-60% of muscle mass/total weight (depending on field position and other anthropometric variables such as bone mass). Low levels of muscle mass will immediately translate into performance limitations for variables such as speed, jumping, and kicking power.

6. The low percentage of muscle mass combined with the high percentage of fat mass is not enough to achieve the expected level of competition for each Academy product. The relationship between these two qualities quickly shows the potential for poor performance in training and competition.

Why are these values so important and relevant for the player’s developmental process control? Because any other variable is directly influenced by them. For example:

1. Speed is limited by a high content of body fat and/or low levels of muscle mass (also by muscle distribution in the body. There is no value in having a lot of muscle in the arm and few in the legs!)

2. The player will present fatigue sooner than required limiting coordination and technical capacity,

3. Decision making will be compromised when fatigue rises decreasing the player’s influence in the game

4. Injury risk increases when the body has to carry an extra load at high-speed.

5. Over the years the excess of body weight for the sport, and the limited amount of “engine” (muscle), overloads all biological systems decreasing the player’s competitive life.

6. These are valuable variables and are rarely used in talent selection and player recruitment decisions.

Inconsistencies between different areas of soccer performance are usually related to the lack of data collection and analysis at critical moments of player development. It creates players with characteristics below the standard for the level of competition that the Academy wants to achieve, therefore decreasing the efficiency of the Academy. Data is not only necessary for professional players but also to help young players get there.

If you are interested in discussing more in detail the presented information, please contact me at



bottom of page