New experiments studying the role of mental fatigue in Esports athletes have revealed that sparkling carbonated beverages can combat cognitive decline without caffeine or sugar in coffee and energy drinks, which can be detrimental to long-term health.
The University of Tsukuba team behind the findings suggests that understanding the role of carbonated beverages on game-related mental fatigue could mitigate the potential costs of cognitive decline in the workplace. The study also highlights a potential alternative to sugary, caffeinated energy drinks for improving concentration and focus.
Esports Athletes Turn to Sugary Energy Drinks to Combat Mental Fatigue
Although people with physically demanding jobs can experience physical fatigue, working for long periods in a highly focused way can result in a similar, purely mental exhaustion. Described by researchers as ‘cognitive fatigue,’ this state can include reductions in cognitive reasoning, focus, and concentration, and even affect one’s sense of fair play.
According to the University of Tsukuba team, people who play competitive esports may not rely on the same physical skills as athletes who play the same sports in real life. However, they note, because playing esports relies on digital interaction and advanced cognitive skills, including spatial reasoning, sustained attention, information processing, and task switching, gaming participants may experience cognitive fatigue “characterized by diminished executive function with pupil constriction.”
To combat the deleterious symptoms of cognitive fatigue, gamers often rely on caffeinated or sugary beverages. However, the researchers note, regular use of sugary and caffeinated energy drinks “poses health risks.”
“Excessive or long-term intake of caffeine and sugar is associated with adverse health effects, including abnormal heart rate, sleep disturbances, impaired glucose tolerance, and increased depressive symptoms,” they explained, adding that research into the effects of cognitive fatigue on competitive esports players remains scarce.
“There is still a lack of empirical evidence on practical, scalable countermeasures for esports players to overcome or manage such fatigue,” they explain.
Although gamers are known to drink energy drinks, the researchers said there was some anecdotal evidence that carbonated ‘sparkling’ beverages may have a similar effect in mitigating cognitive fatigue, especially during “prolonged” esports sessions.
Volunteers Undergo Tests and Drink Water During Three-Hour Esports Session
To study the possibility, the research team enlisted young adult volunteers with an average age of 22.9 years. To ensure more widely applicable results, the volunteers needed to meet certain criteria to be defined as casual players.
After selecting 15 qualified casual esports players, the team conducted a random crossover trial in which each player completed two three-hour gaming sessions of virtual football (soccer). During each session, the study volunteers consumed either plain water or sparkling carbonated water.
While the volunteers played, the study authors administered hourly tests to measure subjective ‘feelings’ of fatigue, the subjects’ overall enjoyment, and their executive function. According to the authors, the latter was measured using a ‘flanker’ task, “in which participants must decide if stimuli flanking a central stimulus are congruent or incongruent–such as arrows pointing in the same or opposite direction.”
To monitor physiological responses, the researchers also monitored the study subjects’ pupil diameter and heart rate, as well as blood glucose and salivary cortisol levels. Pupil diameter is a neuronal biomarker of prefrontal activity. According to the study authors, greater pupil constriction is also associated with slower flanker-task responses, “supporting pupil diameter as an easily measurable sign of cognitive fatigue.”
Results Show Sparkling Water Enhances Enjoyment and Offers Benefits Against Fatigue
When the researchers compared the various tests, the results were significant. For example, when compared to plain water, the researchers found that sparkling water “significantly attenuated increases in subjective fatigue (and) enhanced enjoyment. The study authors also note that gamers who drank sparkling water “preserved executive function, along with preventing pupil constriction.”
When the researchers compared the other tests, they found that, on average, the gamers’ heart rates, intestinal glucose levels, and salivary cortisol “did not differ between conditions.”
An examination of each volunteer’s gameplay also revealed that esports competitors who drank sparkling water committed fewer ‘in-game’ fouls compared to regular water drinkers. However, when the researcher examined their offensive and defensive game performance, they found “no significant changes’ between water types.
“Our findings demonstrate that drinking sparkling water could suppress both subjective and cognitive fatigue during prolonged esports play,” they write, adding that the fatigue-reducing effects of sparkling water “appears to support fair play behavior while maintaining in-game performance,” they write.
Carbonation Stimulates the Brain via Receptors in the Throat
Although more study is required to pinpoint the mechanism behind sparkling water’s protective effect against cognitive fatigue, the University of Tsukuba research team said they are likely mediated by the carbon dioxide that gives the water its fizz to transient receptor potential (TRP) channels in the throat that sense temperature and touch.
“Sparkling water, a sugar- and caffeine-free beverage, stimulates brainstem and prefrontal activity via sensory pathways potentially mediated by transient receptor potential (TRP) channels in the throat,” they explain.
For example, the CO2 dissolved in sparkling water can activate TRP ankyrin 1 (TRPA1) channels in the throat. These sensory channels contribute to the beverage’s ‘cooling sensation’ by inducing intracellular acidification. These types of sparkling drinks also produce tingling sensations in the throat.
The research teams said the bubble-induced sensations activate TRP vanilloid 1 (TRPV1) channels in the pharynx. TRPV1 channels typically mediate the sensation of burning and pain.
“Activation of oral and pharyngeal TRP channels enhances afferent input to the trigeminal nuclei that project to the locus coeruleus, which are key components of the ascending reticular arousal system that influence vigilance and executive control,” they write.
Finally, the study results suggested that sparkling water activated regions of the brain’s prefrontal cortex that are involved in executive functions. This includes brain regions that can be affected by cognitive fatigue, such as the orbitofrontal cortex (OFC).
Therefore, ter searchers write, “sparkling water may also influence cognitive function directly.”
Preventing Problems Associated with Unnoticed Cognitive Fatigue
When discussing the study’s findings, the researchers said they suggest that sparkling water consumption may be an “effective way to maintain mental focus during prolonged esports play” without the potentially deleterious effects of sugar or caffeine intake.
“These findings demonstrate that sparkling water contribute to alleviate both subjective and objective signs of cognitive fatigue during prolonged esports play, consistent with our hypothesis,” they write.
The researchers also highlighted the apparent effects of sparkling water consumption on fair play, noting that non-caffeine interventions for people who experience cognitive fatigue “may help sustain inhibitory control and promote fair behavior.”
Lastly, the team highlighted that modern humans lead lifestyles that “increasingly separate physical from mental activity,” leading to a growing need to address signs of cognitive fatigue when physical fatigue may not be immediately present. Such interventions, they note, could reduce potential long-term health problems “associated with unnoticed cognitive decline.”
“Ultimately, sparkling water could offer a low-risk, sustainable alternative to caffeine- or sugar-based interventions for mitigating cognitive fatigue in modern digital life.”
The study “Sparkling water consumption mitigates cognitive fatigue during prolonged esports play” was published in Computers in Human Behavior Reports.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.