According to nutritionist Dr Joanna McMillan, even mild dehydration can have a negative effect on athletic performance and brain function.
"Eventually you will reach a level of dehydration where you start to have fuzzy thinking or a headache, and it affects the functioning of your gut, you might find you're more prone to constipation or a sluggish gut,” she told smh.com.au.
Most people believe that they should be drinking two litres of water each day, but the amount required is actually dependent on the individual.
"The amount needed varies, depending on individual factors including age, diet, climate and levels of physical activity. For men aged 19-70 it's actually considerably higher, at around 2.6 litres," neuroscientist Dr Sarah McKay said.
A simple skin test will reveal if you are drinking enough water.
Use two fingers to pinch skin for two seconds on the lower arm or abdomen. The skin should tent up, and when it’s released, it should snap back into place immediately.
If you are dehydrated, your skin will take longer to return to its position.
Tips for staying hydrated include eating plenty of fresh fruits and vegetables, drinking plenty of water, choosing vegetable-based juices over fruit based, and drinking water while you’re consuming alcohol. If you’re working in the sun, electrolyte drinks will help keep you hydrated.