Hydration as Brain Food

 09 Nov 2015

Being healthy doesn’t just mean eating your five pieces of veggies, two serves of fruit and a bunch of meat. As it happens, what you drink is just as – if not more – important, and nothing is as successful in clearing up that brain fog quite as much as a big swig of that sweet H2O.

We all know that water is essential to life. As babies, we are 75 per cent water: as adults, about 60 per cent. It’s the lubricant that keeps our joints in good working order, our brains ticking like clockwork and our bodies well-oiled for exercise.

So it probably comes as little surprise that water is very important when it comes to performance, both mental and physical. The benefits of being well-hydrated are long-ranging, and can help you get the best results out of your work, study and physical well-being.


When it comes to exercise, nothing is more important than water. Exercise performance suffers when a person is dehydrated by as little at 2 per cent of their body weight. And just a 5 per cent loss of water in body weight can affect work and performance by as much as 30 per cent. [1]

The ability to tolerate heat also goes down as water intake declines, an important point to keep in mind, especially coming up to summer.

So whether it’s at the gym or outdoors, drinking regularly and making sure to stay hydrated will not only prolong the amount of time you spend exercising effectively, but also boost your performance to get the most out of it. 


Not getting enough water can seriously impact the way you think and perform during the day. Depriving your mind of proper hydration can not only affect concentration but impair visual perception, reaction times and the ability to carry out simple tasks well.

But, as it turns out, it’s not just the physical lack of water that hinders good brain function: the mere sensation of thirst can be so distracting that it affects us in ways that makes getting through the day that bit harder.

According to a study conducted by Caroline J Edmonds from the University of East London School of Psychology, adults and children who are not properly hydrated tend to suffer a decline in mental performance in many different ways, and to various degrees.  

In this particular study, 34 adults – 25 of them women - were asked to refrain from eating or drinking from 9pm the two evenings before their tests. On one day, the subjects were given a fruit bar and water to drink before completing a series of tests, which included pressing a button as soon as they saw an object on a computer screen, while on the other, they were only given the fruit bar, and no water.

What Dr Edmonds found was pretty interesting. It turns out that reaction time was especially affected, with the participants who had drunk water before completing the tests being 14 per cent faster than those who didn’t.

So how to best keep your brain well-oiled? Wake up, drink a big, tall glass of water, and .. And while advice about the exact amount of water to drink tends to vary, the Dietitians Association of Australia has a good water guide to follow: 

1,500 – 2,000mL/day (or 35-45mL/kg/day) for adults, and
1,000 – 1,500mL/day for children

And, to make drinking water more fun, squeeze some lemon juice, pop ice cubes made from fruit into your glass of water, and remember to carry a bottle in your bag to sip on during the day. 

Experience the Zip Effect. It’s easy to drink more and improve your home or workplace productivity with fresh, filtered water on tap.


[1] According to Dr Asker Jeukendrup and Dr Michael Gleeson, http://www.humankinetics.com/excerpts/excerpts/dehydration-and-its-effects-on-performance