By the time you feel thirsty, you are already dehydrated – and this can affect your concentration.
Your brain is 80% water, and relies on being well hydrated for its connectivity – it works best when well lubricated! – and dehydration can reduce both concentration and mental performance.
Kids are particularly affected by this. A study carried out by paediatrician Dr Terry Brocklebank at Leeds University in the UK, in 2002, showed that children’s ability to do arithmetic was impaired even if they were only 1-2% dehydrated – which is not even enough to register a feeling of thirst.
Symptoms of poor hydration can include tiredness, headaches, reduced alertness and less ability to concentrate. Mental performance, including memory, attention and concentration, deteriorates progressively as the degree of dehydration increases.
So much so that, in 2008, the UK’s Expert Group on Hydration published their recommendations in a report, Drinking in Schools.
Recommended fluid intake is 1.5 to 2 litres a day. This doesn’t have to be just water, but bear in mind that some caffeinated fluids – coffee and colas – can have a diuretic effect, actually increasing your output.
So hit that tap, and drink a glass of water.