Mouth rinsing with a carbohydrate solution attenuates exercise-induced decline in executive function

Area of Science:

• Sports Science
• Exercise Physiology
• Cognitive Neuroscience

Background:

• Declines in executive function can impair performance in dynamic activities like sports.
• Carbohydrate mouth rinsing may be a strategy to maintain executive function during exercise.

Purpose of the Study:

• To investigate the impact of carbohydrate mouth rinsing on executive function following sustained, moderately high-intensity exercise.

Main Methods:

• Eight healthy participants ran for 65 minutes at 75% V̇O₂max.
• Participants underwent two conditions: mouth rinsing with carbohydrate solution (CHO) or water (CON).
• Executive function was assessed using the Stroop Color and Word Test; blood glucose and stress hormones (ACTH, epinephrine, norepinephrine) were measured.

Main Results:

• Executive function, measured by reaction time in the Stroop test's incongruent condition, declined after exercise in the CON group but not the CHO group.
• A significant interaction effect (condition × time) was observed for reaction time, indicating CHO attenuated the decline.
• Plasma epinephrine and norepinephrine levels showed a trend towards attenuation with CHO, potentially linking to preserved executive function.

Conclusions:

• Mouth rinsing with a carbohydrate solution effectively attenuated exercise-induced declines in executive function.
• This effect appears to be mediated by the inhibition of stress hormone release rather than direct carbohydrate metabolism.