Water helps us remain hydrated throughout the day, but it can also help us to react and respond faster, a new study shows. When we feel thirsty, we become distracted from what we are doing. This study shows that by drinking more water, we retrieve the ability to concentrate on a given task – important for deadlines and projects that require a high level of mental capability.

The study, led by Caroline Edmonds of the University of East London and researchers at the University of Westminster, tested the cognitive abilities of 34 adult subjects, some who did not have water before the test, some who did. Overall, participants who consumed 3 cups of water before taking the CANTAB cognitive tests reacted faster than those who did not drink water right before the test. Naturally less thirsty individuals were not affected by their water consumption, but those who have a higher thirst were. These results suggest two things: that a person’s natural thirst influences the effect drinking water has on their reaction speed; and the feeling of not having enough water negatively affects our reaction speed, allowing water to have a positive effect and curbing this physiological sensation.

The study called for 34 adults to remain from food and drink after 9 PM the night before the tests. The study lasted two days, and in the mornings some adult participants were allowed a cereal bar with water, and others were given a cereal bar without water. Adults with a naturally high thirst level and who did not drink at night or the morning of the test were slower to respond to the cognitive tests, while those who also had a high natural thirst but consumed water performed better. Participants with a lower natural thirst were unaffected; their reaction speed was the same as those who were very thirsty but who had consumed water before the test.

Edmonds thinks the feeling of not drinking or drinking could have a physiological effect on the brain due to the hormone that activates the “thirst response” – vasopressin, she tells LiveScience. Vasopressin is associated with cortical arousal, which is key in the level of the human attention span and consciousness. People usually turn to caffeinated beverages to increase their attention spans; this study shows that water can help in their search to perform better and faster. A simple and easily accessible element for many of us, a few glasses of water in the morning can increase our speed for the daily tasks ahead.