Sparkling Water Beats Coffee for Fighting Fatigue, Study Finds

Drinking sparkling water instead of coffee or energy drinks when feeling fatigued at work can help maintain focus without harming your health, according to new research.

Researchers at Japan's University of Tsukuba conducted an experiment to examine how carbonated water affects cognitive fatigue, the UK's Daily Mail recently reported.

The research team had 14 young casual gamers play a virtual soccer game for three hours while drinking either regular water or unsweetened sparkling water. Participants consumed approximately 500ml of beverages during each session and repeated the same experiment days later with the drinks switched.

The results showed participants who drank sparkling water experienced significantly less increase in subjective fatigue compared to those who drank regular water and maintained better concentration. Participants also reported enjoying the game more when drinking sparkling water.

Researchers measured pupil diameter and heart rate during the experiment to analyze fatigue and alertness levels. The sparkling water group showed less pupil constriction, a phenomenon associated with increased cognitive fatigue. This group also committed fewer fouls during gameplay.

"Participants committed fewer fouls during matches when drinking sparkling water, while offensive and defensive performance remained unchanged," the researchers said.

This suggests benefits beyond simple concentration improvement, indicating that judgment and impulse control abilities—executive functions prone to decline with fatigue—were also maintained.

Researchers explained that carbon dioxide in sparkling water may stimulate sensory receptors in the mouth, potentially increasing brain alertness. However, they noted this study compared sparkling water with regular water, not directly with coffee or energy drinks.

While caffeine and sugar are frequently used to alleviate cognitive fatigue, excessive consumption can negatively impact health. In contrast, no health risks have been reported associated with regular sparkling water consumption, according to the researchers.

The study was published in the international journal Computers in Human Behavior.

Can Sparkling Water Replace Regular Water?

Sparkling water is considered one of the healthiest beverage alternatives. It provides satisfaction similar to sodas like cola and cider while containing no sugar or caffeine. Drinking sparkling water daily can help increase fluid intake even for those who don't drink enough plain water.

However, patients with irritable bowel syndrome or gastroesophageal reflux disease should exercise caution, as carbonation can increase gas in the stomach and intestines, worsening bloating or reflux symptoms. Additionally, prolonged exposure to sparkling water's mild acidity may erode tooth enamel, so using a straw or rinsing with water after consumption is recommended.