Physiological Base of muscle Conditioning

Muscle conditioning is the ability to train one’s muscles to a degree of contraction different from normal, obtaining a better neuromuscular response (tone), a better resistance (endurance) and a better nutritional status (trophism).

Our locomotor system consists of about 400 muscles. Each muscle is enveloped by a more or less thick connective membrane called the “muscular fascia” that contains it; it is activated by neuromuscular impulses received by the general propioceptors (neuromuscular spindles) that are activated during muscle contraction.

The latter, linking the motor area of the brain with the muscles, inform us about the state of muscular tension, the direction of the body with respect to the space and the positions of the various parts of the body with respect to the others.

The whole system of stimulation and response of muscular activity takes place thanks to the energy provided by the splitting of an energetic molecule called ATP (adenosine-triphosphate) which is the basis of all energy processes.

Before going into specific muscle contraction techniques, you need to know which energy systems are used during a movement. From this awareness the trainer can set his own programs according to the needs of the athlete or the subject subjected to muscular conditioning.

Aerobic Activity, Alactacid Anaerobica and Lactacid Anaerobica.

The energy supplied to perform muscle contraction can be used simultaneously and in various measures; the energy supply systems are of three types: Aerobic, Anaerobic lactacid and Anaerobic alactacid (see benefits of gymnastics).

It can therefore be said that the energy choice to which the muscle is subjected depends on the extent of its muscular commitment. This will be determined by the intensity and the working time the muscle will undergo (running for a long time, taking a shot of 100 Mt. or kicking a ball).

Aerobic activity has already been discussed in the chapter on aerobic gymnastics and in short it is nothing but muscle work in balance between consumption and reintegration of energy substances. It is typical of long-term activities (marathon, cycling, cross-country skiing etc.) and is carried out in the presence of oxygen for the synthesis of glycides and fatty acids.

The Anaerobic alactacid system is very intense and can be carried out for a very short time (about 8-10 seconds); it is used for maximal efforts (lifting weights) and is linked to the number of energy accumulators already present inside the muscle cell (the creatine phosphate). This energy of ready use does not need oxygen and does not produce lactic acid, so once exhausted, to continue the work, it must necessarily require the help of other energy systems such as anaerobic lactacid.

Anaerobic Lactacid is the medium-high intensity energy system that comes to be interested in most of our daily actions; in fact the duration of its action is concentrated in 45 seconds 1 minute approximately.

The use of this energy system is evidenced by the production of lactic acid produced by the splitting of glycids (anaerobic glycolysis) as a waste element of the energy produced in the absence of oxygen.

The result is a sense of fatigue and slowing of muscle contraction, which in some cases, when the production is so high, is not disposed of by the liver or converted into pyruvic acid and literally blocks muscle contraction causing the so-called cramp.

Types of muscle contraction.

When we talk about muscle contraction we always think of a shortening of the activated fibers; but in reality, depending on the dynamics of movement, the force arising from muscle contraction is closely linked to biomechanical aspects.

For biomechanical aspects we mean the dynamic action of the movement that makes the articular segments to which the muscle involved in the contraction is inserted (eg biceps femoris: pelvis-femur-tibia).

In general, three types of contraction are identified which are:

Concentric contraction (overlying or isotonic) The two articular heads approach during contraction (lift a load, eg: the arm lifts a suitcase).

Eccentric contraction (or donor) The two articular heads during muscle contraction move away (the muscle tries to resist the load, eg the arm lays the suitcase on the ground).

Isometric (or static) contraction During the muscular contraction the distance between the two articular heads remains unchanged (the load is neither won nor yielded to it, eg the arm keeps the suitcase raised).

The combination of these three types of contraction, can give rise to two other subspecies of biomechanical situations destined to the delivery of force, such as:

Plyometric contraction obtained with a rapid inversion from an eccentric to a concentric contraction exploiting the elastic energy of the muscle accumulated in the first type of contraction (eccentric eg: bottom and rebound).

Auxotonic contraction which is the combination of isometric and isotonic contraction (predominance of the latter, eg: starting from the blocks of 100 meters).

The specificity of muscular action

We have seen how the muscle can take on different roles based on the position of the articular segments. We can define the muscle:

agonist when he performs the movement;

antagonist when he performs the opposite movement to the agonist muscle.

It is evident that from the moment in which the muscle moves the bone segments in its favor it takes the name of “agonist”. During the contraction of the agonist muscle, the antagonist acts as a modulator, that is, it decides on the basis of neuromuscular impulses (Sherington’s law) and, maintaining a certain tone and control, assures the right coordination of the movement.

We can distinguish “three” behaviors of the muscle based on the action it performs:

synergistic when it is not the main effector of the movement but participates equally as an agonist.

fixator when, with a static contraction (isometry), holds balances the segments on which another segment moves (ie: abdomen muscles fixate the pelvis while the psoas-iliacus raises the lower limbs).

neutralizer and driver when contracting neutralizes the action of other muscles, especially biarticular, whose complete intervention would not allow the ability to locate the movement on a single joint (eg: Quadriceps femoris in flexion of the leg by the Semitendinous, Semimembranosus and Biceps femoral that otherwise, continuing in their action, would extend the thigh).

The principles of muscle conditioning training

Muscle conditioning training can be divided into two large families:

naturally charged when using a body segment (raising an arm) or your body (jumping, running).

with overload, when an external body (weight) is used. An example of natural overload: from the lateral decubitus position, by raising a lower limb (abduction) the load is represented by the weight of the limb; while, at a later stage, the work is defined with overload by applying an ankle brace.

Before starting muscle conditioning, it is necessary to apply some physiological principles that the trainer must keep in mind so that the neurophysiological adaptations we are looking for will occur. They are:

  • the specificity;
  • muscle balance;
  • the principle of overload.


For specificity of the movement we mean the identification of a muscle group to work on and then isolate it from all the other muscles. This means searching for movements whose range of action can apply the load only on a specific muscle group (for example, to act specifically on the medial portion of the deltoid muscle it is sufficient to abduct the upper limb in a short or semibreve attitude on the plane frontal up to 90 ).

During the exercise you will then have to fix the point of gripping of the joint and isolate the chosen muscle, mobilizing it in a specific way.

Muscle balance

The principle of muscular balance is based on balancing the effort between the agonist and antagonist muscles.

The work produced must be harmonious and rational so as not to have a predominance of muscle tone of one group with respect to the other. This work allows to fix the joints in the correct position, indirectly reinforcing the posture.

By varying the point of application of the load on the flexor and extensor muscle groups, according to the “Law of Alternation”, a temporary active rest is allowed which makes the response to the subsequent stress more efficient.

The principle of overload

As we have described before, overload can be natural, with your body, or with the help of a weight. In both cases there is resistance against the muscle that is induced to react. When overloads are applied, some basic principles must be kept in mind to avoid the onset of trauma, especially tendons and ligaments, which can easily trigger inflammatory processes.

While muscle cells adapt quickly to minors or greater signals of tension coming from the nervous system, tendons and ligaments, to adequately and firmly support a load, must rely only on the structure of their tissues, and not on nervous mechanisms and therefore it is it is necessary to wait for the necessary biological modifications to take place with new and higher tensions. It follows that we must stand on a certain load, a certain number of days (at least 10-15) before increasing it, even if the muscles would be able to do so, in order to give time also to tendons and ligaments to adapt.

In short, the load must grow not linearly, but “stepwise”. One possible scheme could be this, for each exercise: to start with a weight that allows the execution of eight repetitions; always with the same weight, after a few days, pass to 10 repetitions, then to 12. Only at this point, ie after about 2-3 weeks, according to the subject, the weight is increased, but returning to perform eight repetitions per series.

In the period when the weight remained constant, the tendons could develop a normal adaptation. Often, however, erroneously, we tend to hasten time by increasing the load to rapidly increase the capacity of strength and muscle mass, but the consequences on the ligaments will not be long in coming.

The Total Body Conditioning

It is the English term used to identify muscular conditioning techniques.

During the training specific exercises are carried out from the standing station, in quadrupedas, in lateral decubitus, prone and supine. The first objective is to improve the tone-trophic state of those muscle groups responsible for maintaining a correct posture (paravertebral muscles, dorsal muscles, buttocks and quadriceps).

The second goal is that of all women, namely the elimination of female blemishes going to act on all the “bearing” areas, ie toning the parts of the body in which the excess fat is deposited (abdomen, hips, buttocks and thighs). The two objectives can be summarized with a single muscular work: – muscle definition – that is to determine the optimal percentage of individual body fat (fat mass) and that of muscle tissues (lean mass).

Body Conditioning is the most used technique in gyms and is a fundamental component of all gym classes.

Body Conditioning work can be performed

free body

(body weight only)

with the help of small tools

Let’s start now with a series of free-body exercises.