Monitoring of (central) fatigue - part 1 - for everybody


Why fatigue monitoring is so important?

As the degree of fatigue increases, the overall training effect decreases because the body does not have the capacity to adapt to the workload. When it comes to long-term (chronic) fatigue, also actual performance decreases. With an increasing degree of fatigue, the probability of chronic overload and health complications increases! Why risk it then?

Fatigue monitoring (peripheral and central) is essential for anyone looking for an effective way of training. It does not matter whether the goal is to increase performance or "only" maintain fitness and health.
For correct interpretation, a combination of information about four, fortunately, available factors, is necessary.

They are:

• Level of the previous load
• Perception of peripheral fatigue
• Level of central fatigue
• Long-term ability to resist to central fatigue and load - i.e. adaptation capacity presented by mySASY Training profile


What fatigue really is?

The answer to this question may be surprisingly complicated. Fatigue is not merely a “decrease in physical performance due to previous stress”. The modern definition describes fatigue as a "non-specific symptom", a condition that can have several causes and manifestations. But which are they?

In the sports environment, training / physical performance is considered as a primary cause. However, a number of neurophysiological and psychological changes also affect the level of fatigue, which may be caused by both training and other, and more difficult to identify, effects of the internal and external environment. The sum of these influences then fundamentally affects the body's ability to perform optimally and, above all, to properly adapt to the load.

It is essential to perceive the fact that fatigue manifests itself in two basic forms:


1.1. Peripheral fatigue

It is induced by the load on the working muscles and is manifested by a (transient) decrease in physical performance and the ability to adapt to the load. Its primary manifestations are mainly (not exclusively) caused by two basic factors. The first is the depletion of energy reserves, especially ATP and muscle glycogen, making it impossible to continue muscle work The second factor is the accumulation of metabolites that arise in the working muscle and hinder it from further activity. Peripheral fatigue can be seen simply as what we feel when we have “tired muscles” after training. As we know, this type of fatigue is relatively well subjectively perceivable and evaluable. It corresponds well to the previous load level.


1.2. Central fatigue (CF)

It is often described as fatigue not originated from working muscles but from the central nervous system (CNS), which affects the transmission of information from the brain to the working muscles.
The human body is a very complex system whose primary goal is to maintain a balanced internal environment and ensure the long-term survival of the body.
The above-mentioned influences from the internal and external environment can cause “central fatigue”, which significantly slows the return of the internal environment into a previous balance.

The level of this type of fatigue then very complexly affects the ability of the body to realize the next loading without risk of negative health impact. This manifestation of (central) fatigue is (unlike peripheral fatigue) quite individual and is not subjectively “perceivable”.



It is clear from the above that the assessment of central fatigue (CF) offers a completely new, yet untapped, potential for enhancing the effect of training, improving the health of the organism globally, and preventing overload and damage to health.

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