The Soccer Coach

- arrests and braking;

- changes of direction;

- ball controls;

- contrasts with opponents.

In other words, the soccer game is a succession of different performance for intensity type according to the game’s development and occurs within a specified period of time. Any combination of soccer performance with those of other disciplines (e.g. athletics) is really arbitrary and wrong. The soccer player from an athletic point of view is to be considered just a player and that's it. The 8,000 meters of the player's run are divided as follows:

- walk about 20% (~1.600 meters);

- slow running about 35% (~2.800 meters);

- reaches 25% (~2.000 meters);

- sprint 15% (~1.200 meters);

- backwards running about 5% (~400 meters);

Midfielders usually run higher distances than defenders and forwards. The amounts of running and the type of gait vary a lot from role to role and in the role itself in relation to the physical-athletic characteristics and above all the player's characteristics.

The distances run at maximum speed vary from 3/4 meters up to 25/30 meters, the most frequent are 10/15 meters and are repeated 50/60 times.

I also find it interesting to present the results of a study on heart rates expressed by players during a competition. The recorded values show that the player is not subject to very high tensions.

For each half of a game the following pulsating frequencies were detected:

These figures lead to some general considerations:

1 there are significant differences between the average performance of the various players;

2 with the exception of the central defender all the other players are subjected to a wide range of stimuli;

3 in the defenders and midfielders the period of average intensity prevails while for the forwards we have the longest period of minimum intensity, but also the longest of maximum intensity.

Let us now try to analyze how movement and training can produce changes in our body. For convenience I will describe separately the effects of the movement produced on the muscles, on the joints, on the bones, on the internal organs, on the mind and also on the relationships with others, but it is necessary to keep in mind that often these effects occur simultaneously.

EFFECTS ON MUSCLES

Muscles are the active organs of movement, in fact they are made up of fibers that contract in the presence of impulses (nervous commands).The movement produces the following transformations on the muscle:

1 increase in volume: the muscle, if made to work intensely to lift weights or to overcome a resistance, becomes bigger and at the same time increases its force.

2 increase in length: the muscle maintains or increases its length by means of continuous work to which it is subjected, the muscle lengthening allows to fully exploit the joint width.

3 increased capillaries: the muscle, engaged in a work of mild intensity, but of long duration, increases its capillarization that is the number of channels that bring the oxygen (brought from the blood) to the muscle fibers. This results in an improved ability to supply the oxygen muscle: a condition that allows the muscle to resist fatigue for longer.

4 increase of energy substances: the movement allows the increase of energy substances (glycogen) necessary for muscle contraction.

5 improving the transmission of nerve stimuli: training makes the transmission of nerve stimuli from the brain to the muscles faster and more precise, thus improving the speed and coordination of movements.

EFFECTS ON JOINTS

The joints constitute the “junction” system of our body. They allow the movement of the various body segments. The articulation consists of the union of two bones whose ends are called articular heads. The movement produces the following transformations on the joints:

1 maintenance of physiological mobility: the articulation to maintain its normal mobility must be used to the maximum of its possibilities of movement.

2 increase and recovery of mobility: to recover lost mobility and increase that possessed, it is necessary to use particular forms of training and movement.

3 strengthening of the articular capsules: the joint capsule, made up of ligaments and muscles, has the task of keeping the articular heads firmly tied and to prevent the joints from getting out of place and that sprains or dislocations occur.

EFFECTS ON BONES

The bones constitute the scaffolding of our body, they fulfill the task of protection (the skull protects the brain, the spine protects the marrow) and contribute, as passive organs to the movement, to the displacement of the body and its limbs. The movement produces the following transformations on the bones:

1 better nutrition: the increased circulation of blood, caused by physical exercise, nourishes the bone tissue and supplies it with calcium.

2 development in length: the movement favors the production of new bone cells, which determines the growth in length of the bone itself.

3 development in width and thickness: the tractions on the bones, exercised by the muscles during movement, favor the development of the same in thickness and width. It follows an increase in resistance.

RESPIRATORY EFFECTS

The task of the respiratory system is to supply the body with oxygen and to eliminate carbon dioxide. The movement produces the following transformations on breathing:

1 reduction of recovery time: the trained subject takes less time to return to normal breathing after the effort.

2 minor increase in respiration rate: the trained subject, with the same work, has a lower basal respiratory rate than the sedentary (12-16 acts per minute).

3 increase in vital capacity: the vital capacity is the amount of air, measured in liters with the spirometer, which is able to emit with a forced exhalation, after having done a maximum inhalation.

4 increase of the apnoea time: the apnoea, or voluntary suspension of the breath, increases in duration in the trained subject.

5 strengthening of the respiratory mechanics: the respiratory muscles, and in particular the diaphragm, with the exercise increase their power and the efficiency of their contractions.

EFFECTS ON THE HEART AND CIRCULATION

The circulatory system consists of the heart (pump), the great circulation (arteries and veins that carry blood to the various tissues, the organs of the body and bring it back to the heart), the small circulation (which brings blood to the lungs to oxygenate them and brings it back to the heart).Physical activity produces evident effects on the cardio-circulatory system, among these the most expressive are:

1 the shape of the heart changes: the heart of an athlete becomes almost spherical.

2 the heart becomes thicker: the internal cavities (atriums and ventricles) increase in volume and the muscular walls thicken.

3 the systolic range increases: the amount of blood expelled at each contraction (systole) of the heart is greater because the internal volumes and muscle strength have increased.

4 cardiac output increases: the amount of blood put into circulation in one minute.

5 heart rate increases: the number of pulses per minute increases during work. Remembering that with the same work, the trained subject will have a lower number of pulsations thanks to the capacity of his heart to pump a greater quantity of blood.