Summary: Many esports athletes rely on sugary energy drinks or caffeine to endure long tournaments, but a healthier, simple option may already be in the fridge. Researchers at the University of Tsukuba report that unsweetened, highly carbonated (sparkling) water helps players sustain mental focus, lowers signs of cognitive fatigue, and increases enjoyment during prolonged three-hour gaming sessions, compared with plain water.
The team proposes that the tactile sensation of carbonation in the throat stimulates brainstem pathways that help keep prefrontal brain regions—those responsible for decision-making and attention—more active during extended mental effort.
Key Facts
- Cognitive maintenance: Players who drank sparkling water performed significantly better on executive-function tests (flanker tasks) than those who drank plain water.
- The “throat hit” connection: Carbonation’s physical sensation appears to activate sensory pathways from the mouth and throat into brainstem-to-prefrontal circuits linked to attention and inhibitory control.
- Fatigue reduction: Sparkling water reduced subjective exhaustion and prevented pupil constriction, a physiological marker associated with cognitive fatigue.
- Fair play boost: Participants consuming carbonated water committed fewer fouls in virtual soccer matches, indicating improved inhibitory control; offensive and defensive performance otherwise remained similar.
- Healthier substitute: Benefits were achieved without added sugar or caffeine, avoiding the long-term health risks tied to frequent energy drink consumption.
Source: University of Tsukuba
Overview of the study
Published in Computers in Human Behavior Reports, this randomized crossover trial tested whether unsweetened, highly carbonated water can mitigate cognitive fatigue during extended esports play. The study recruited young adult participants who completed two separate three-hour sessions of a virtual soccer game while consuming either sparkling water or plain water.
Throughout each session, researchers continuously monitored pupil diameter and heart rate, and collected periodic measures of interstitial glucose and salivary cortisol. Participants reported subjective fatigue and game enjoyment each hour and completed an executive-function assessment using the flanker task, which evaluates selective attention and response inhibition.
Compared with plain water, sparkling water consistently attenuated increases in subjective fatigue, preserved flanker-task performance, and reduced the degree of pupil constriction that typically accompanies prolonged cognitive effort. Heart rate, interstitial glucose, and cortisol levels did not differ meaningfully between conditions. Notably, players drinking carbonated water committed fewer in-game fouls, suggesting improved inhibitory control without changes in primary offensive or defensive performance metrics.
Why carbonation may help
The authors suggest that sensory signals from the oral and pharyngeal mucosa—triggered by intense carbonation—activate transient receptor potential (TRP) channels and other mechanosensory pathways. These inputs travel through the brainstem and connect to prefrontal areas that support executive function and sustained attention. In effect, the constant mild stimulation provided by highly carbonated water may act as a non-pharmacological cue that helps the brain maintain control during extended mental work.
Key Questions Answered
A: If your priority is sustained focus and endurance without the crash from caffeine or sugar, the study suggests yes. Sparkling water did not produce a stimulant buzz but helped participants stay precise and commit fewer errors over long sessions.
A: Sensory inputs from the mouth and throat are relayed through the brainstem, which has direct connections to the prefrontal cortex—the brain’s hub for decision-making and attention. The fizz provides a continuous mild sensory signal that may help sustain these circuits during fatigue.
A: The study used unsweetened, highly carbonated water. According to the researchers, the intensity of carbonation—the pronounced “fizz”—appears to be the critical factor.
Editorial notes
- This article was edited by a Neuroscience News editor.
- The journal article was reviewed in full by editorial staff.
- Additional explanatory context was provided to clarify methods and results.
About this research
Author: Press Office, University of Tsukuba
Source: University of Tsukuba
Contact: Press Office – University of Tsukuba
Image credit: Neuroscience News
Original research: Sparkling water consumption mitigates cognitive fatigue during prolonged esports play — Shion Takahashi, Wataru Kosugi, Seiichi Mizuno, and Takashi Matsui. Computers in Human Behavior Reports. DOI: 10.1016/j.chbr.2026.100943 (open access).
Conclusions
This study provides evidence that unsweetened, highly carbonated water can be a practical, non-pharmacological strategy to lessen both subjective and objective markers of cognitive fatigue during extended esports play. By stimulating sensory pathways without added sugar or caffeine, sparkling water may help players maintain executive control, reduce errors and fouls, and enjoy longer sessions more comfortably. While further studies with larger and more diverse samples are warranted, these findings point to a simple, low-risk option for sustaining mental focus during prolonged gaming or other demanding cognitive tasks.