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The importance of strength training in soccer. Improving performance in young footballers

strength training in soccer

In this article we will talk about the importance of strength training in soccer for youth category for football players and how to improve their performance during game. First  of all lets understand this fundamental concepts.


Osteogenesis is the process that leads to the formation of bone tissue, starting from mesenchymal tissue.
Bone tissue cells can be classified into:

  • Osteoblasts: responsible for the formation of bone tissue;
  • Osteoclasts: responsible for the demineralization of bone tissue;
  • Osteocytes: maintain the functioning of bone tissue.

The osteogenesis process is divided into two different types:

  • Direct ossification : in which the mesenchymal cells of the embryo organize themselves into ossification centers, in which they specialize into osteoblasts, forming the first bone tissue, i.e. the non-lamellar bone tissue with intertwined fibres;
  • Indirect ossification : the process that forms bone from hyaline cartilage, and occurs in long bones. Long bones are made up of a central body (diaphysis) and two ends (epiphysis). During growth, and therefore during the ossification process, the ossification center of the diaphysis moves in the direction of the epiphyseal centers, thanks to the replacement of the bone tissue with cartilaginous tissue, guaranteeing its growth in length. When the diaphyseal center meets the epiphyseal center, growth in length from the diaphysis ceases.

The growth in width of the diaphysis, however, is guaranteed by the process of periosteal ossification, by the apposition of layers of bone tissue by the osteoblasts of the internal layer of the perichondrium, which subsequently transforms into the periosteum (anatomy of the human body, M. Gesi , M. Ferrucci, G. Ghelarduzzi, CLD libri ).

Many scholars have debated the bone growth process, and one of the most important contributions comes from a German surgeon Julius Wolff, who focused attention on Wolff’s law.
According to this principle, the bone microstructure adapts to a regularly applied mechanical load. This means that, during the growth phase, the bones can receive mechanical stimuli derived from physical and sporting activity.

In fact, many studies have shown that during the period of adolescence, in which the bone grows and develops, by administering regular mechanical stimuli the bone can benefit from its development in length and thickness. ( High Impact Exercise Improves Bone Microstructure and Strength in Growing Rats, Tanvir Mustafy, Irène Londono, Florina Moldovan, and Isabelle Villemure, 2019)

Muscle tissue and bone tissue: two related tissues

Other studies have been interested in the interaction between bone tissue and muscle tissue. Both tissues are of mesodermal origin, and together they constitute the locomotor system. This apparatus performs multiple functions, among which we find the stability of the skeleton, the ability to give movement and the ability to adapt to the surrounding environment.

These two systems not only manage to develop and influence each other in an extremely dynamic way, but they involve other elements of the organism such as the metabolism and the nervous system.

strength training in soccer |Biomolecules | Interactions between Muscle
Interactions between Muscle and Bone Where Physics Meets Biology, 2020

From this image we can see how these two tissues intersect with each other and with the other systems of our organism. Specifically, this photo shows that an increase in the muscular system (hypertophy) corresponds to an increase in bone mass, an important element during the growth development of a boy.

This principle is related to Wolff’s law described previously. By administering the right training stimuli, the muscle hypertrophies, i.e. the thickness of the muscle fibers increases, which produces a positive effect on the growth of the bone itself.

These stimuli, however, must be appropriate to the age of the child and in line with his physiological maturation.

All this is possible because during physical exercise, physiological mechanisms are created which positively influence both bone and muscle growth, such as the opening of calcium channels which affect both muscle contraction and density. bone. Or again like the secretion of nitric oxide (NO), prostaglandins that interact with the bonds of actin filaments (responsible for muscle contraction) modifying the volume of muscle cells.

Precisely for this reason, many studies have stated that both the muscular system and the bone system could have an endocrine function. As regards the bone, the action of growth factor β (TGFβ) can influence the differentiation of the myoblast and thanks to osteocalcin (glycoprotein) it produces the differentiation of osteoblasts controlling bone mineralization, metabolic control, brain development and in males, fertility.

Furthermore, in association with vitamin K, osteocalcin can determine insulin control and glucose absorption at the muscle level ( Interactions between Muscle and Bone—Where Physics Meets Biology, Marietta Herrmann, Klaus Engelke, Regina Ebert, Sigrid Müller-Deubert , Maximilian Rudert, Fani Ziouti, Franziska Jundt, Dieter Felsenberg, and Franz Jakob,2020 )

The muscular system releases particular enzymes, called cytokines, into the bloodstream, which exert their effects on other organs, carrying out different tasks: for example, they inhibit the secretion of Myostatin (responsible for preventing muscle growth). Interleukin -6, on the other hand, has an anti-inflammatory action that prevents diseases such as diabetes, heart failure and metabolic syndrome.

Another important cytokine is BDNF (Brain-derived neurotrophic factor), it is found in the brain and a low index can indicate Alzheimer’s disease ( -physical-exercise).

Central Nervous System Adaptations

As with bone and muscle tissue, the central nervous system (CNS) also has adaptive changes produced by training. Below we see some examples:

  • Increased blood flow : blood circulation increases proportionally to the percentage of muscles used in training;
  • Improved mood : linked to the production of endorphins, so the longer the effort is maintained over time, the faster the speed of endorphin synthesis;
  • Improvement of sensory activity : training produces an increase in sensory activity, linked to the organ predominantly involved in the activity. For example, in sports games such as football, where vision is affected, an improvement in the visual cortex but also an improvement in static and dynamic vision has been demonstrated.
  • Hypertrophy of cortical areas : various research confirms that with training there is an increase in synapses and an increase in neuron density.

Strength training produces peculiar and specific adaptations in the CNS, also affecting the muscular system. Among these adaptations we can find the improvement of intra and intermuscular coordination. During effort, the muscle is able to recruit a greater number of motor units (intramuscular coordination); furthermore, in improving performance, the muscle groups are activated in a targeted manner, and therefore the interaction between agonist and antagonist muscles becomes optimal (intermusdular coordination), thus reducing synkinesis (accessory movements) to a minimum which can lead to a worsening of the performance itself .

In addition to this type of adaptations, we also find hypertrophy and hyperplasia: after having improved intra- and intermuscular coordination, the muscle adapts by increasing the cross-section of the individual muscle fibers (hypertrophy), and subsequently leads to the formation of new muscle fibers (hyperplasia).

Furthermore, several studies have shown that depending on the load used, an increase in anaerobic-lactacid capacity can be produced (intensive stimuli, for example strength and speed resistance loads), or an increase in aerobic resistance, increasing the reserves of glycogen from intramuscular fats, an improvement in transport systems (extensive stimuli) ( optimal training, J. Weineck, Calzetti and Mariucci )

Strength development in young soccer players

From the analysis done so far, we can deduce how important it is to perform strength training in young people, especially during growth development.

A study conducted by F. Perroni et al. ( Effect of pre-season training phase on anthropometric, hormonal and fitness parameters in young soccer players, 2019 ) wanted to analyze the impact of strength training on hormonal levels (testosterone, cortisol and DHEAS) and of children of an average age about 14 years old.

After making an anthropometric assessment and pubertal development (administering a questionnaire to quantify pubertal development), the study analyzed the performance of a Countermovement Jump (CmJ) and the Yo-Yo Intermittent Recovery test level 1 for 8 weeks. The same showed significant differences in anthropometric, hormonal and fitness parameters between the data taken before and after the tests; and a correlation between fitness and hormonal parameters.

This study confirmed not only that performance was related to anthropometric values ​​and pubertal development (i.e. the best performing players were those with higher values ​​in both anthropometric values ​​and the pubertal scale); but also that performance was also correlated to the hormonal values ​​of testosterone and cortisol. In this case the study analyzed performance in the CmJ and the Yo-Yo test, finding correlation with hormone levels: also in this case the best performing players were those who had higher values.

From these results we can deduce the importance of strength training in the training of young footballers.

Another study, conducted by S. Hermassi et al. ( In-Season Weightlifting Training Exercise in Healthy Male Handball Players: Effects on Body Composition, Muscle Volume, Maximal Strength, and Ball-Throwing Velocity, 2019 ), on handball players, analyzed the maximum strength (1RM) of the typical weightlifting exercises bench press, pull-over, snatch and clean and jerk, correlated to the speed of throwing while standing, running and jumping.

This study took subjects with an average age of 21 years, divided into two groups: the experimental group and the control group.

During the 8 weeks of work, the control group maintained the standard training model, while the experimental group supported a weight lifting program twice a week to maximize strength performance.

This study made it possible to indicate that after 8 weeks during the competitive season, implementing the training program with the typical weightlifting exercises, bench press, pull-over, snatch and clean and jerk, allowed not only to improve specific sport performance, but also to improve physical performance.

Strength Training For Soccer PDF Book!




From this article, we can deduce how training, especially strength training, can improve performance in young athletes.

The strength training methodology must follow the development of the athlete, therefore the training loads must respect the natural and physiological development of young footballers.

As described in the previously reported articles, the development of strength brings adaptations at the bone and muscular levels and also at the level of the central and normal nervous system, adaptations that lead to the motor, perceptive and growth development of the young athlete.

From all these adaptations, an improvement in physical performance also results, which can lead to the development of talent.


Anatomy of the human body, M. Gesi, M. Ferrucci, G. Ghelarduzzi, CLD libri.

Tanvir Mustafy,Irène Londono, Florina Moldovan, and Isabelle Villemure, High Impact Exercise Improves Bone Microstructure and Strength in Growing Rats, 2019

Marietta Herrmann, Klaus Engelke, Regina Ebert, Sigrid Müller-Deubert, Maximilian Rudert, Fani Ziouti, Franziska Jundt, Dieter Felsenberg, and Franz Jakob, Interactions between Muscle and Bone—Where Physics Meets Biology, 2020 exercise -fisico ;

Optimal training, Jurgen Weineck, Calzetti and mariucci

Fabrizio Perroni, Simona Fittipaldi, Lavinia Falcioni, Lucia Ghizzoni, Paolo Borrione, Mario Vetrano, Riccardo Del Vescovo, Silvia Migliaccio, Laura Guidetti, Carlo Baldari, Effect of pre-season training phase on anthropometric, hormonal and fitness parameters in young soccer players, 2019;

Souhail Hermassi, Mohamed Souhaiel Chelly, Nicola Luigi Bragazzi, Roy J Shephard, and René Schwesig, In -Season Weightlifting Training Exercise in Healthy Male Handball Players: Effects on Body Composition, Muscle Volume, Maximal Strength, and Ball-Throwing Velocity, 2019

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