Water Intervention Improves Performance

Posted by:

Water Intervention Improves Performance

Preceding blog posts have covered a vast number of studies that examined the effects of different hydration levels on performance – from the importance of encouraging proper hydration at work to maximise productivity, to the detrimental effects of dehydration on driver performance. But in a part of their paper, Effects of hydration status on cognitive performance and mood, researchers, Masento and van Reekum, approached hydration matters from a different perspective; they listed studies across a variety of different subject groups that examined the benefits brought about by a water intervention – giving water as opposed to withholding it.

Taken directly from the Masento et al research paper, herewith an excerpt from each intervention to illustrate that water intake leads to improved performance:

Drinking water improves visual sustained attention

Methodology: Young adults assigned to a no-water, 120ml or 330 ml water condition; asked to perform a rapid visual information-processing task.


The researchers found a dose related improvement in performance, with those in the 330 ml water condition performing the best of the three groups and the no-water group performing the worst.


Despite a variety of studies which changed experimental design and varied the amounts of water given; consistently the result has been that water consumption improves the cognitive function of visual sustained attention.

Drinking water improves short-term memory 

Methodology: School children aged between 7-9 years given up to 250 ml of water to drink; asked to perform a ‘spot the difference’ task.


The visual memory of the children who drank more water was significantly improved in comparison to those children who had drunk less.


Three independent studies investigating water intervention in school children showed that short-term memory is improved after water consumption.

Drinking water improves simple reaction time

Methodology: Adults asked to rate their thirst levels prior to the experiment; assigned to a no-water or water supplementation condition; asked to perform a simple reaction time task.


Thirsty individuals performed significantly worse in the no-water condition; with non-thirsty individuals exhibiting a relatively similar performance independent of water intake.


This study shows the importance of baseline hydration levels – those subjects who were thirsty at the start of the experiment and were not given water during the trial were potentially mildly hydrated which in turn slowed their reaction times. 

Drinking water improves mood 

Methodology: Young adults assigned to no-water or water supplementation conditions; asked to perform a range of cognitive tasks and mood ratings.


Mood ratings were shown to significantly change when individuals were given water. Individuals reported feeling more ‘calm’ and ‘alert’ immediately after water consumption.


In those studies where mood measures have been included, water consumption has been shown to improve alertness and other arousal states, but more research needs to be done to examine the extent to which these moods are affected.

The researchers conclude their paper by commenting that:

Accumulating evidence supports the notion that hydration state affects cognitive ability and mood. Severe dehydration has been shown to cause cognitive deficits such as short-term memory and visual perceptual abilities as well as mood disturbance, whereas water consumption can improve cognitive performance, particularly visual attention and mood.

In short, it is proof yet again that remaining properly hydrated is essential to improved function and performance.

Add a Comment