Overdoing exercise can overwork your brain to the point that your decision-making is compromised, a new study says.
The findings suggest that even with the benefits of endurance sports, excessive training load can have negative effects on your brain.
“Our findings draw attention to the fact that neural states matter: You don’t make the same decisions when your brain is in a fatigued state,” said study author Mathias Pessiglione of Hopital de la Pitie-Salpitriere in Paris.
In the study, researchers had 37 male endurance athletes either continue normal training, or increase their training by 40% a session over three weeks. MRIs showed the overloaded athletes had a slower response in the lateral prefrontal cortex.
Further, athletes who went overboard to the point of exhaustion displayed limited activity in the area of the brain responsible for making decisions. They seemed more impulsive in their choices; in financial decision-making, they seemed to go for immediate rewards, rather than larger ones that take more time to attain, for example.
“The lateral prefrontal region that was affected by sport-training overload was exactly the same that had been shown vulnerable to excessive cognitive work in our previous studies,” Pessiglione said in a journal news release.
This area of the brain was a weak spot when it came to cognitive control — the ability to process information and control behavior, he said. The study also hypothesizes that both mental and physical efforts are important for cognitive control. They even go so far as to say it may be a good idea to monitor fatigue levels outside of athletics, ensuring decisions in areas like politics, law, and finance, aren’t influenced by exercises’ effects on the brain.
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