Defecation after magnesium supplementation enhances cognitive performance in triathletes

Area of Science:

• Neuroscience
• Gastroenterology
• Sports Science

Background:

• Constipation is linked to reduced cognitive function, suggesting a gut-brain axis connection.
• Elite athletes may experience cognitive challenges during intense competition, potentially exacerbated by gastrointestinal issues.

Purpose of the Study:

• To investigate the causal link between rectal state and cognitive function in elite athletes.
• To assess the impact of defecation, with and without magnesium oxide, on cognitive performance and brain activity.

Main Methods:

• A counter-balanced crossover trial involving 13 elite triathletes performing the Stroop test.
• Cognitive function was assessed with and without magnesium oxide intake, separated by a 1-week washout period.
• Near-Infrared Spectroscopy (NIRS) measured prefrontal and sub-navel region oxygenation and blood flow during cognitive tasks.

Main Results:

• Defecation significantly reduced Stroop test completion time compared to the non-defecated state (p < 0.05).
• Magnesium-induced defecation improved Stroop test performance in 100% of participants; non-magnesium defecation improved it in 69%.
• Decreased oxygenation was observed in the sub-navel region post-defecation, indicating increased oxygen consumption.

Conclusions:

• Rectal emptying state has a direct impact on cognitive performance.
• Magnesium supplementation, by improving rectal emptying, offers a potential strategy to optimize cognitive function in athletes.
• The sub-navel region's oxygen consumption changes suggest a physiological link between gut function and brain activity.