A new study has shown that excessive exercise not only causes muscle fatigue but can also affect the brain. The authors of the study conclude that exercising too much can limit our ability to make well thought out decisions.
A recent study has shown that intensive training can affect cognitive abilities. Researchers at the Hôpital de la Pitié-Salpêtrière in Paris, France, have discovered that over-training syndrome can affect the brain and the rest of the body.
Overtraining syndrome is a form of exhaustion in endurance athletes. It occurs as a result of heavy strain on physical training.
The authors are of the opinion that this form of fatigue can affect some of the same nerve pathways as fatigue as a result of intense mental work. Scientists have already discovered that fatigue as a result of excessive mental effort can influence cognitive control.
Cognitive control, also called Executive Control, refers to a person’s ability to change behavior and thoughts in order to achieve goals and accomplish tasks.
Abusing exercise overloads the body
Overworked physical training leads to a significant drop in performance because athletes feel overburdened by fatigue. The researchers wanted to investigate whether the overtraining syndrome was partly due to nervous fatigue in the brain and also to muscle fatigue.
They were also interested in the question of whether overtraining affects the same part of the brain as excessive intellectual work. The group recruited 37 professional athletes with an average age of 35 years. The participants continued their regular exercises or increased their training by 40% per session for 3 weeks.
Athletes participated in cycling exercises on rest days so that researchers could track their physical performance. They also completed questionnaires asking what they thought of their subjective experience of fatigue. Finally, the researchers used behavioral tests and MRIs to assess the cognitive abilities of the participants.
The study showed that over a period of 3 weeks overload of physical training has led to fatigue and has caused the athletes to behave differently.
In economic decision evaluation tests, tired athletes were more impulsive. The MRI showed that the physical overload of the athletes caused a dysfunction in the lateral activation of the prefrontal cortex. This part of the brain is responsible for general cognitive control, including decision making, planning, behavioral inhibition, and motivation.
Of particular importance are the motivational operations that determine how the brain processes information. The results of this study show that athletes who have experienced physical overload are generally more impulsive. In particular, they opted for immediate rewards rather than larger rewards that would take longer to obtain.
The authors explain that endurance training is generally good for your health, but in some cases, it can have an unexpected effect on your brain.
This study was the first to show that physical training can also cause cognitive fatigue.