Sympathetic and parasympathetic nervous system

When stressed, excessive activity occurs in the sympathetic nervous system. This means that the body is kept in a constant state of alert and there is no opportunity for recovery. Such a situation can arise due to excessive physical exertion. Since mental effort is just as physical as exercise, mental stress can also cause serious stress complaints. The balance between the sympathetic and parasympathetic nervous systems is then lost. In other words, the balance between accelerating and braking is lost. At rest, the parasympathetic nervous system predominates. The body, including that part we call the mind, needs this to recover. Training is only effective if there is sufficient time for recovery in between. Then supercompensation also occurs. The phenomenon that the body recovers after rest to above the previous level. Although never proven, this could also be the case with mental training or learning. Exercise has a beneficial effect on the balance between the sympathetic nervous system and the parasympathetic nervous system. Exercising three times a week is an ideal frequency to ensure an optimal balance between physical training and sufficient recovery. A condition is that the training is not too intensive. because then more rest is needed to recover. The consequence for secondary education could be to include an hour and a half of physical education on the schedule at least twice, but preferably three times a week. Of course, many students exercise at least once a week at their own sports club, but this exercise is crucial for the increasing number of students who do not do so. In addition to increasing learning ability, overall health also increases because it helps to prevent obesity.

Untrained people mainly use glycogen as fuel, while trained people get much more energy from fat reserves. Moreover, in someone who is untrained, the increased heart rate and blood pressure also causes extra glycogen burning and the released stress hormones in turn also break down glycogen. It is very important for learning that a shortage of glycogen hinders the functioning of the brain. Neurons are completely dependent on glycogen for their energy supply. Fat is unsuitable as an energy source for the brain. The brain is by far the largest energy consumer of all organs. So for untrained adolescents who live under long-term stress, there is insufficient glycogen available for the brain to function properly. This causes concentration problems and memory problems. Not only when retrieving information from long-term memory, but also when processing information in working memory.


There are several important systems involved in the interaction between the sympathetic and parasympathetic nervous systems. Exercise strain and mental strain constantly lead to shifts between the two systems and that can have major consequences. Stress stimuli in childhood play a crucial role later in life. A major problem is that if the body is unable to return to the recovery state of the parasympathetic nervous system, it becomes less and less able to maintain blood pressure.

The heart rate variability

An important indicator to determine the extent to which this disturbance occurs is heart rate variability. Heart rate variability is the variation in time between two heartbeats. It is the measure of the parasympathetic control of the heart. The variation may not be zero, so for example exactly one second between each heartbeat, but it must also not show large irregular outliers downwards or upwards. The time between two heartbeats differs due to natural acceleration and deceleration. When you inhale, the heart rate increases and when you exhale it decreases. So it depends on breathing and breathing is the only function of the autonomic nervous system that we can consciously do something about. By consciously controlling breathing, you can influence heart rate variability and thus the degree of stress. In addition to breathing, exercise also affects heart rate variability. When exercising, the muscles need more energy. To ensure this, the heart must pump more blood. This causes an increased heart rate and blood pressure. Regular, not too intensive exercise influences heart rate variability in two ways. Training lowers the heart rate at rest, increases heart rate variability and slows down the sympathetic nervous system more. Exercise also affects energy consumption. This is an important point for secondary education. It ensures that obesity decreases and learning capacity increases. The body can supply energy in two ways. On the one hand, by using glucose (sugar), which is stored in the muscles as glycogen, and on the other hand, by using fat that is stored around the abdomen, buttocks and breasts. The difference between the two energy stores is that the amount of glycogen is used up much faster. is. Just think of the infamous hunger pangs. When a person has a lack of glycogen, he becomes disoriented. He can no longer concentrate and staggers on his legs.