Fatigue during muscular activity
Fatigue should be considered as a complex process, affecting all levels of activity of an organism (molecular, cellular, organ, whole organism) and is manifested in the totality of the changes associated with shifts of homeostasis, regulating, autonomic and Executive systems, development of a sense of fatigue, temporary loss of efficiency.
At the beginning of intense muscular activity the performance of the athlete is constantly increasing – is vrabotuvanje . The presence of the period of work is a biological pattern and is typical for any job. During
the period of work is developing the necessary movement patterns, is the mobilization of the autonomic functions of the body systems, which mainly ensure the delivery of this work. The period of work is shorter in athletes of high qualification (high level athletes, reach their maximum oxygen consumption after 60 to 90 seconds, and athletes second, third discharge takes 2 – 3 minutes).
After the period of work work is performed for a certain period of time at a relatively constant level of health is in steady state (sustained performance). At this time, is achieved by coordinated activity of motor and autonomic functions. Violation of a condition of stable availability is due to the development of the process of fatigue.
We should distinguish the concepts of exhaustion and fatigue.
Fatigue is a special kind of person’s functional state, temporarily caused by prolonged or intense development, resulting in reduced efficiency .
Fatigue is a subjective perception and reflection of this process that protects the body from excessive depletion .
Fatigue is a decrease in strength and endurance of muscles, poor coordination, increased energy costs when doing the work of one and the same work, in slowing reactions and speed of information processing and other phenomena.
In relation to intensive muscular activity it is expedient to distinguish between explicit (non-repayable) fatigue and latent (compensable) fatigue.
Explicit fatigue manifested in decreased performance and refusal to perform work in a given mode due to uncompensated changes in the activities of regulatory and enforcement systems .
Hidden fatigue is characterized by demonomania of work, significant changes in patterns of movements, but not accompanied by decreased performance due to the use of compensatory mechanisms .
Diagnostics of fatigue is very important for rational planning of various structural formations of the training process. If the explicit definition of fatigue virtually no difficulties in the power of clear and objective criterion for its existence – health, it is possible to estimate the latent fatigue is much more difficult.
The first signs of latent fatigue associated with a reduction in efficiency, deterioration of intramuscular and intermuscular coordination, significant changes in the coordination structure of the movements, occur more often early in the second half. Gradually these changes are amplified in the direction of a deeper exhaustion of functional reserves and reach the maximum available for the job values during the transition of hidden fatigue in explicit, i.e. at the moment a noticeable decrease in the health of the athlete.
The main indication of the occurrence of hidden fatigue can be the energy consumption per unit of mechanical work. It is a significant increase in energy consumption in relation to the indicators steady state indicate the use of inefficient compensatory mechanisms maintain the health and development of latent fatigue.
Research conducted by scientists showed that repetitive muscle activity of the cyclic character of great and submaximal intensity, signs of fatigue begin to show through a period of time equal to 45 – 55% of the total hours of work performed before the onset of obvious fatigue. Hidden fatigue is accompanied by a subjective, often very strong feelings of fatigue. In the other direction offset fatigue develops later, usually after running 60 – 75% of the total volume of work before the onset of obvious fatigue.
Training in the compensated state of fatigue is very effective to create specific conditions, adequate activity of the athlete in the competition, when he, overcoming fatigue, seeking to achieve high sports results.
In performing any exercises we can identify the main, leading, most downloadable system, the functionality of which determine a person’s ability to perform this exercise at this level of intensity or quality. The utilization of these systems to their maximum capabilities defines the maximum duration of this exercise, ie the period of the onset of fatigue.
Thus, the functionality of the leading systems not only define, but also limit the intensity and limit the duration but also the quality level of this exercise.
When performing different exercises causes of fatigue varies. The consideration of the causes of fatigue is caused by two main concepts. The first concept – localization of fatigue, i.e. the allocation of the host system (or systems), functional changes, which determine the condition of fatigue. The second concept – mechanisms of fatigue, that is, those specific changes in the activities leading functional systems, which cause fatigue.
When studying the localization of fatigue the first thing to pay attention to three groups of systems that provide any of the exercises:
1) regulatory system – the Central nervous system, autonomic nervous system and garmoyle-humoral system;
2) the system is autonomic components of muscle activity of the respiratory system and blood circulation.
3) Executive system – skeletal (peripheral neuromuscular) apparatus.
When performing any exercise functional changes occur in the nerve centers that control the activities and governing its vegetative management.
The most sensitive to fatigue are cortical centers. Manifestations of fatigue of the Central nervous system are the lack of coordination of body functions (particularly movements), the emergence of feelings of fatigue.
Fatigue may be associated with changes in the activity of the endocrine glands and the autonomic nervous system. The role of the latter is especially great if you are doing long exercises. These changes may lead to impaired regulation of autonomic functions, energy supply of muscular activity, etc.
The reason for the development of fatigue can be many changes in activities of autonomic systems components, primarily respiratory and cardiovascular. The main consequence of these changes is a reduction in the oxygen transport capacity of the organism working athlete.
Fatigue may be associated with changes in the activities of the Executive office – working muscles. When this muscle (peripheral) fatigue is the result of changes occurring in the contractile apparatus of muscle fibers. Muscle fatigue is manifested in reduced contractile ability of muscles.
In the modern system of sports training fatigue plays a mainly positive role in its development and compensation are essential to improve the functional capacity of the organism, a kind of stress syndrome, which should be widely used in various sports to stimulate adaptive changes in the body of an athlete.