14 DAY TRIAL // It would appear that human physical performance is directly influenced by the individuals' state of mind, and, most importantly, by mental fatigue, the conclusion of a new scientific study reveals. The research left investigators puzzled, because they learned that no matter what a person's limits were tested to be, he or she always underperformed after a series of mentally-challenging tasks. The results will be detailed in the March issue of the Journal of Applied Physiology.
Researchers Samuele M. Marcora, Walter Staiano and Victoria Manning, from the Bangor University in the United Kingdom, say that the peak of activity is reached much faster in the case of people who are mentally fatigued than in that of their peers who have performed no soliciting task. They share that these differences can be explained by the concept of “perceived effort,” which shows how people come to realize that they are exhausted following intense effort.
If an individual's state of mind is positive, then he or she will be able to perform physical exercises to the limits of their strengths, without feeling any kind of supplementary strain on themselves. But if a person has just finished performing a complicated mental task, and is asked to go through a lot of physical effort, his or her mind will perceive the additional undertaking as overwhelming and will trigger the feeling of exhaustion sooner than normal.
According to Dr. Marcora, there are two distinct possibilities as to why this is happening. The first hypothesis would be that mental fatigue lowers the brain's inhibition against quitting, which in turn makes people give up more easily. The second theory is that this state affects the expression of dopamine, a brain chemical tied to motivation and effort, which has the same effects.
The discovery has potential applications in the army, where soldiers are made to stand as sentinels, which is a very mentally-challenging task that requires attention. Then, they are put through demanding physical exercises, which can cause them to become exhausted sooner than normal. The Army could use these data to compile a physical exercise program that would maximize the energy output of those serving in the army.