Too much exercise tires the brain and reduces the ability to make decisions

Is sport bad for our brain?

Exercise and physical activity not only tire the body, but also the brain, which can affect decision-making and rational thinking.

The latest study by the French Institute of Sport, Expertise and Performance (INSEP) has now found that physical activity has a tiring effect on the brain. The results of the study were published in the English-language journal "Current Biology".

Less activity was found in part of the prefrontal cortex

As a result of an intensified training routine, the triathletes examined were not only physically exhausted, their mental abilities were also limited, the researchers report. The ability to make decisions was worse because people were less able to think rationally and resist temptation. Brain scans also showed that participants had less activity in a part of the prefrontal cortex that is involved in control after exercise. This seems to be essentially due to the fact that the brain is exhausted by the mental efforts that are required to achieve the athletic training goals. The lateral prefrontal region affected by sports training overload was exactly the same region that previous studies classified as prone to excessive cognitive work.

Does exercise affect the brain like intellectual work?

The team attempted to assess whether over-training affects the brain in the same way that over-intellectual work does. For this purpose, 37 male endurance athletes with an average age of 35 years were examined. The participants were instructed to either continue their normal training or to increase it by 40 percent over a period of three weeks. All individuals were medically monitored to ensure that they were not exercising to a harmful degree. The fatigue experienced by the participants was measured every two days using questionnaires. On the rest days of their training program, the participants were additionally guided through a series of cognitive tests between the sporting exercises. At the same time, the researchers performed MRI scans to determine what was going on in the brain.

Effects of too much exercise

The study showed that overtrained athletes acted more impulsively and preferred immediate rewards to larger rewards that would take longer to achieve, the team reports. Brain scans also showed that participants had reduced lateral prefrontal cortex activity when making these decisions. The lateral prefrontal cortex is a region of the brain that plays a critical role in deciding and processing rewards. The results indicate a connection between mental and physical exertion, both of which require cognitive control. The researchers report that cognitive control is always required when familiar processes have to be monitored, interrupted and modified in order to better align behavior with long-term goals. Maintaining physical exertion during fitness should therefore require cognitive control. Endurance sports (such as running or cycling) are generally good for your health, but excessive exercise can have a negative impact on the brain. The results draw attention to the fact that neuronal states are important: the researchers do not make the same decisions when the brain is tired. (as)

Author and source information

This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.

Swell:

• Bastien Blain, Cyril Schmit, Anaël Aubry, Christophe Hausswirth, Yann Le Meur, Mathias Pessiglione: Neuro-computational Impact of Physical Training Overload on Economic Decision-Making, in Current Biology (query: 27.09.2019), Current Biology

Video: Coronavirus Impact: Talking to Kids About Schedules, Change, and Disruption (July 2022).