physiology of training

Train the red fibers in the Body Building

The red fibers naturally constitute ALL the muscles of the body MA in EXTREMELY VARIABLE percentages between them. They are predominant in the muscles responsible for mild and repeated (long-lasting) efforts, also known as tonic-postural muscles.

The red ones are not the preferred fibers in Body Building training but their more or less marked presence significantly affects the training technique to be used.

Briefly: shortening of the fibers

The movement takes place thanks to the nervous stimulation of the neurons on the muscles; the latter can be defined as organized tissues and deputies to the contraction (shortening of the fibers) "enclosed" in a membrane of connective tissue (epimysium) . Internally, they are organized in several parallel bundles covered by the perimysium (another membrane) and within them contain the muscle fibrocells, also called myocellules. These fibers are POLINUCLEATE, a feature that suggests the fusion of several units in a single cytoplasm; the contraction unit of the fibrocellula is the sarcomere, which shortening determines muscle contraction .

The final functional units consist of two proteins, actin and myosin ; to make the contraction happen, slipping one over the other (thanks to the breakdown of the adenosine-tri-phosphate) transforming the molecular energy into energy of movement .

Different types of muscle fibers

Muscle fibers are of three types:

  • Lens, oxidative and red / type I (plus oxidative enzymes, mitochondria, myoglobin and capillaries)
  • Intermediate, oxidative - glycolytic and white / IIA type (they adapt to both energy metabolisms)
  • Fast, glycolytic and white / type IIB (plus glycolytic enzymes, glycogen, phosphocreatine and creatine kinase)

The white fibers (especially the IIB) are assigned to short and intense efforts; together with the motor neuron that innervates them, they determine the performance of tension and speed of contraction which (translated into athletic terms) is equivalent to force and speed . These glycolytic fibers are the most useful in the development of mass in Body Building, as they have high reserves of glycogen and creatine-phosphate (CP) in the cytoplasm (greater overall cell volume) which increase muscle hypertrophy by increasing.

NB . In hypertrophy (predominant element for the increase in muscle mass in Natural Body Building) there is another very important factor: the stimulation and specialization of satellite cells. In reality they are real stem cells, that is small units that, in the absence of external stimuli such as training or intense muscle damage, remain in a vegetative state; on the other hand, if conditions warrant it, satellite cells could evolve into specialized (muscle) units repairing the lesion or increasing the overall volume of the fibrocells. This is a mechanism that I consider closer to hypertrophy than to hyperplasia because the satellites are cells already present within the tissue; however, it is frequent to read about other authors who consider the mechanism a real increase in the number of muscle fibers, hence hyperplasia.

The nature of muscle fibers (or better, of motor units) is influenced by several factors:

  • Type of muscle (each muscle has a composition of fibers - white and red - different from the others)
  • Portion of the muscle considered (many muscles, such as the quadriceps and the pectoral, have bundles characterized by a different qualitative prevalence of motor units)
  • Genetics and individual predisposition (chromosomal heritage and attitude towards short-intense or prolonged-mild muscle strains)
  • Training technique (prevalence of aerobic or anaerobic efforts).

Red fibers in the muscles

The red fibers concentrate mostly in the muscles and bundles assigned to:

  • Maintenance of posture (internal lodges; spine supporters)
  • Pulmonary ventilation (internal and external intercostal, scalene, small pectoralis, diaphragm etc.)
  • Ambulation (psoas iliac, vast lateral quadriceps femoris, soleus, etc.)
  • Movements of the upper limbs repeated frequently (deltoid, biceps brachialis, tall bundles of the great pectoralis etc.).

As it can be noticed, sometimes it is possible to identify whole muscle bundles or precise areas of the muscles that have motor units (therefore muscle fibers) different from the near ones (it is the case of the great pectoral); this "variety" is determined above all by the predisposition to a movement and / or custom to carry it out frequently without reaching high intensity of effort. Wanting to make a trivial example, in human evolution, the deltoid and upper bundles of the pectoral probably developed with many red fibers to facilitate the "collection" of the fruits from the trees; similarly, the vast medial quadriceps (thigh muscle) has good amounts of white fibers to improve the power of the shots in hunting and / or escape.

Red fibers and Body Building

The goal of Body Building is the development of a muscular and proportionate body. To do this it is necessary to train the muscles aiming mainly at hypertrophy (increase in muscle mass) and cutting (definition of muscle mass).

To train the hypertrophy it is necessary to impose on the muscle a training stimulus that determines:

  • The exhaustion of the fabric through specific strength exercises
  • The depletion of creatine phosphate (CP) and glycogen reserves

Furthermore, it is also advisable:

  • Leave the right recovery to promote supercompensation to the training stimulus (tissue repair and replenishment of reserves)
  • Feed yourself correctly
  • Sleep right and promote hormonal cycles.

In light of what has been explained so far, a question naturally arises: Do the muscles with different fibers all train in the same way? The answer is no.

Apart from the technique used, it would be advisable to stimulate the red fibers in a different way from the white ones. In Body Building it is customary to use tables with exercises that are repeated 3 to 12 times (repetitions) for a variable number of series (from 3 upwards). To correctly stimulate a predominantly red fiber bundle it is NOT recommended to use the same repetitions and the same recoveries useful for the development of white fibers! To put it simply: In order to increase athletic performance and obtain a more "decisive" metabolic response of red fibers it is appropriate to maintain:

  • A higher number of repetitions
  • Lower execution speed
  • More contained recoveries.

Set on the development of PURE FORCE (for example 3-5 repetitions and recoveries up to 3 ') MONOARTICULAR exercises such as the "CURL with BILANCERE" (which isolate the muscles with a high content of red fibers) DOES NOT give the same benefits as the performance itself with more repetitions and shorter recoveries. This difference in stimulus effectiveness is determined by the energy metabolism of red fibers ; they are innervated by "slow" motoneurons (which do not allow a rapid contraction speed) and have an energy metabolism that does not allow the production of HIGH amounts of energy and lactic acid in a short time ( NB lactic acid peaks = stimulation of the hormone anabolic somatotropic GH).

The post-exercise sores are mainly related to the strong lacerations of the fiber, which will repair itself in very long times and therefore difficult to contextualize in any training table for hypertrophy. If instead we increase the repetitions in order to allow the right production of lactic acid without "massacring" the district (maybe even reducing the recoveries) we could obtain more satisfactory results; ex: 4 sets of 12-10-10-8 or 12-10-8-8 with recoveries from 90 '' to 120 ''. In this way, the recovery times will be superimposable to those of the other muscle districts and the training table will be easier to organize.

In conclusion, to draw up an effective Body Building training table it is first of all necessary to take into consideration both the subjectivity and the histological variability of the various groups and muscle bundles; the difference between the various motor units requires an extra precaution on the design of the table which, if SE envisages the isolation of muscles with a prevalence of red fibers, must NOT do so with exercises too focused on the contractile force.

Bibliography:

  • Neurophysiology of movement. Anatomy, biomechanics, kinesiology, clinic - M. Marchetti, P. Pillastrini - Piccin - pag 29-30.