Education resources › Blog › 4 reasons why you should drink water in an exam

4 reasons why you should drink water in an exam

3 min read
  • Study skills & exam prep

With the weather finally getting warmer staying hydrated is sound advice, but does drinking water in an exam improve student grades? Should you tell your students to drink water before an exam and even take a bottle of water in the test with them? Essentially, what are the psychological benefits of staying hydrated?

Research suggests that those who drink water in an exam receive an average boost of 5%, with some getting a 10% increase compared to their peers of similar ability who did not. One of the researchers encourages teachers to tell their students to take water into an exam as it is “a really cheap way students and educators can help get better results”. So why would drinking water in an exam help?

Why you should drink water in an exam

Drinking water improves memory and attention

A recent experiment tested the impact that drinking water has on the attention and memory of children. The researchers found that having additional drinks of water significantly improved the children’s ability to focus, as well as being able to retain and recall more information. What is interesting to note is that this effect in children “are the group that has produced the only consistent findings in this area”.

Drinking water improves decision making

What impact does heat exposure and dehydration have on cognitive performance, particularly decision making?  This study found that participants performed significantly worse on psychological tests after a period of heat and exercise (which induced dehydration). They found that performance decreased both half an hour and two hours later. This difference only subsisted after 3.5 hours (though the participants did report still feeling quite tired).

These findings suggests that students who are dehydrated at lunch-time may not only suffer in their first lesson or exam back after lunch, but potentially until the end of the school day.

Boost your students’ study skills and give them the best chance at academic success, with an evidence-informed workshop.

Drinking water improves mood

The previous studies cited suggest that drinking water and staying hydrated improves our ability to execute a task, by improving both memory, attention and decision making. But does it also improve our mood? Research suggests it does. In a study on college sports team, found that athletes who were thirsty were far more likely to report being in a negative mood. For tips and suggestions on how to help manage negative moods, check out our blogs on ‘Challenging Unhelpful Beliefs’, ‘Managing Nerves’ and ‘How to Handle Revision Stress’.

Drinking water improves how alert you feel

A rather curious study once investigated the impact that dehydration has on alertness. They found that although participants didn’t perform any worse on a range of psychological tests, the participants were much more likely to rate their performances as worse if they felt dehydrated. This included them being more likely to report feeling sluggish and less alert. They also said the task took more concentration and effort if they were dehydrated, with results seemingly larger for females than males (although the researchers didn’t indicate why this may be the case).

If students feel that they did worse in their exam then they actually did, this may lead to them feeling frustrated about their performance when going in to the next one. This could trigger a potential decrease in subsequent exam performances. 

Final thoughts

Staying hydrated and drinking water regularly in the heat allows students to deliver their best when it matters the most. It allows them to demonstrate their knowledge, as staying hydrated is associated with an increased ability to recall information, to stay focused on the task at hand, to feel alert and to help boost mood. All these are key skills needed to perform well under exam pressure.

About the editor

Bradley Busch

Bradley Busch

Bradley Busch is a Chartered Psychologist and a leading expert on illuminating Cognitive Science research in education. As Director at InnerDrive, his work focuses on translating complex psychological research in a way that is accessible and helpful. He has delivered thousands of workshops for educators and students, helping improve how they think, learn and perform. Bradley is also a prolific writer: he co-authored four books including Teaching & Learning Illuminated and The Science of Learning, as well as regularly featuring in publications such as The Guardian and The Telegraph.

Follow on XConnect on LinkedIn