Institut du Cerveau – ICM team leader (INSERM researcher) who publish his work on excessive training load effect on brain in current Biology.
Neuro-computational impact of physical training overload on economic decision-making
What are your main important findings?
We identified a specific signature of fatigue as described by triathletes after an excessive training load, which combine a reduced activity in the lateral prefrontal cortex and a preference shift toward immediate rewards when tested for decision-making.
What is the original hypothesis leading to this project?
This study had been conducted in collaboration with INSEP, a national sport institute In France and funded by the French anti-doping agency. The fact that some athletes were victims of the so-called “overtraining syndrome” leading to performances plummet and an intense sensation of fatigue that they could not prevent, explain and cure, except trying to recover with doping practice motivate the INSEP, a national sport institute In France and the French anti-doping agency to solicit our team for his neuroscience expertise.
Our contribution was to suggest that overtraining could arise from a specific form of neural fatigue in the brain, which could also be induced by excessive intellectual work.
Did anything you found surprise you?
Our results suggests a bridge between mental and physical effort: both require cognitive control, which is regulated by the lateral prefrontal region shown by the team to be vulnerable to excessive cognitive work.
To maintain physical effort, to finish a race for example, you need to control the automatic process that makes you stop when muscles or articulations hurt.
What would you like for a general audience to take away from your work?
Overtraining load could affect your brain by inhibiting the activation of your prefrontal cortex leading to impulsive decisions more present-oriented.
What are implications of your findings?
You don’t make the same decision when your brain is in a fatigue state. This may be important to monitor fatigue level in order to prevent unsuitable decisions in economic, political and judicial domains. Those results may be useful for sport training but also for work management in general.
What’s next for you and this line of research?
We are currently testing the hypothesis that a regulation loop in the brain inactivate the cognitive control when it has already burned too many metabolic resources or accumulated too many metabolic wastes.
We plan to use MR spectroscopy in order to quantify brain metabolites during cognitive tasks. We also tend to identify appropriate treatments to prevent fatigue in the cognitive control system developing breaks appropriate sequences during work or medications such as dopamine, noradrenaline or serotonin known as neuromodulators.