work out

plyometrics

What is Plyometrics

The term Pliometry comes from the Greek and means "increase the size / distance". In the study of human movement, in particular, this term describes a complex type of exercise.

Plyometrics and plyometric executions were introduced by the US Fred Wilt, who in 1975 brought them to the attention of the world sports community, describing how " a movement characterized by the succession of a concentric contraction to an eccentric can be a very useful tool in development of some motor-conditional skills (basic and composite) ".

How does it work

According to the principles of plyometrics, in a RAPID eccentric contraction (lengthening of the muscle) the serial functional units (tendons and cross-bridges - actino-myosinic bridges) store energy to free it (like an ELASTIC) in addition to the subsequent concentric contraction (shortening of the muscle). The result is a contraction that uses both the energy forfeited in the eccentric phase, and the energy released in the concentric active contraction.

NB . Plyometrics is an essential technique in the training of sports that require an increase in: reactive force, elastic strength and explosive force (in addition to the combinations of all three), such as fast races, jumps and athletics launches .

Practical example

We start from the assumption that the mind and the human body already have the tendency and the instinct to perform executions and movements more effective than others; just think of a child who tries to cross a puddle with a leap: he quickly squats, accumulating elastic energy and, with a thrust of his arms, exploits his reactive, elastic and explosive force, reaching the high side of the water, and cushioning the landing by flexing the legs.

Plyometrics, with all due respect to its discoverer who revealed its existence, has always been an integral part of the human movement, so much so that, in some exercises with overloads for pure FORZA or for HYPERTROPHY, it contributes to increase the ERRORS of execution. How many times, in the musculature gyms, have you (rightly) witnessed the lectures of the instructors who recommend: << In the performance of the squat or the press, do not perform the negative phase too quickly closing the joints in "bounce"! It can be extremely dangerous and favor the onset of ligament, tendon and muscle injuries ... without considering that, to train muscle mass, the execution MUST be as slow as possible ! >>.

On the other hand, perceiving greater contractile efficacy and efficiency (... and leaving the passive task of supporting the eccentric / negative phase of the movement to the joints), any young athlete is inclined to neglect the performance deliveries of the exercise, rebounding (thoughtlessly!) to reduce fatigue, accumulate elastic energy and release it in the next execution; a practice to say the least creepy.

If nothing else, the "tendency to rebound" can still be exploited by performing plyometrics exercises; these executions, which I reiterate, have nothing to do with the protocols of force or hypertrophy, EVEN IF THEY ARE REBALING ON THE JOINTS, they allow to promote the elastic capacity through rapid succession of eccentric-concentric dynamic contraction. A CLASSIC plyometric exercise aimed at developing the elastic force of the lower limbs for the fast runner in athletics is the ½ SQUAT JUMP CONTINUO. Let's see how it is done:

  • The starting position is upright, with the feet shoulder-width apart and the tips of the feet turned outside by about 30 °; on the shoulders is loaded a barbell (which passes behind the neck) more or less heavy (based on the level of preparation) held firmly by the subject with his hands
  • The athlete quickly falls into eccentric contraction until the angle of the knee joint is at 90 °
  • Reached the point, it reacts in a rapid-elastic-explosive way stretching the legs and taking a small vertical leap (short flight phase) due to the concentric contraction
  • At the brief stage of flight, following the contact with the floor occurs by controlling the eccentric movement and descending again to the angle of the useful articulation to new cycle.

Requirements for maximum yield

Plyometrics is a technique that requires a certain care in the execution of the gesture and in the management of the overall training. First of all, what not many people know is that the effectiveness of the elastic response to the plyometric stimulus is proportional to the eccentric contraction speed, ie: stretching speed ...> response in the subsequent concentric contraction; the concentric contraction response therefore depends on the potential for accumulation of KINETIC elastic energy. What happens if the eccentric distension / contraction speed decreases? Simple! A lower accumulation of elastic energy occurs with greater heat production and a concentric contractile response that is less rapid and less strong (therefore less effective).

NB . It seems that the increase in muscle temperature is also related to an increase in tissue inflammation, but in the absence of a specific bibliography it is not easy to understand whether it is:

  • A physiological and biomechanical aspect
  • An aspect more related to the poor muscular elasticity of the athlete who is injured easily, causing inflammation and therefore an increase in temperature.