- We need constant hydration to replace body fluids lost through sweating, breathing and other bodily functions
- Around 45-60 per cent of an adult’s body is made up of water
- The longer our body is deprived of fluid the less efficient it becomes
- Our ability to feel thirst diminishes as we age
Drinking water, quite simply, keeps you alive (1). Two thirds of the adult body is made up of water and it performs vital roles in the body including ferrying essential nutrients to cells, removing waste products from the body and regulating body temperature (2).
As the body is constantly losing water through sweat, urine and breath it needs replacing daily. Even mild dehydration (which may not even register as you feeling thirsty) can impair short term memory and concentration making you feel confused, tired, demotivated and possibly irritable and angry (3).
How much water do you actually need?
This will depend on your size, how much physical activity you do, how hot the weather is etc. The European Food Safety Authority recommends as a guide 2.5 litres [2,500mls] a day for men and two litres [2,000mls] for women daily.
It suggests 70-80 per cent of this should come from drinks and 20-30 per cent from food, (choose foods with a high-water content like juicy fruit and vegetables including watermelon, celery, cucumber, radishes and apples).
As an indicator of whether or not you are sufficiently hydrated look at the colour of your urine. If it is clear or very pale you are fine. If it looks amber or yellowy you should probably be downing more water.
Water can give you more energy
Doctors are increasingly finding patients who complain of feeling tired all the time are in fact dehydrated (4). Your body needs regular water to keep your energy levels topped up so if you are regularly feeling worn out start monitoring how much you are drinking and see if increasing levels energises you.
Water means a sharper brain
There is a range of evidence to show how dehydration can impact on cognitive ability including concentration, focus and reaction time. A 2017 study found drinking just 300ml of water (roughly just over half of a small standard bottle) can boost attention span by nearly a quarter (5).
Water can support better joint health
Your joints are surrounded by cartilage (made up of around 80 per cent water) which helps create the sponginess needed to cushion them and stop them grating and rubbing. If your joints are feeling stiff and achy this could potentially be a sign you are not drinking enough water (6).
Water can enhance exercise performance
Without sufficient water your muscles can’t contract effectively, they become more prone to cramping and might struggle to repair themselves when you have finished exercising.
If you haven’t exercised for a while or are doing it in hot weather you might also be more at risk of dehydration as your body is not acclimatised to the heat or the increased activity (7).
Keep a measured sports bottle handy to measure and monitor your fluid levels.
Water may help weight loss
One study (in dieting overweight women) found that drinking water was shown to significantly help with losing body fat and weight over time (8).
Water could improved gut health
One of the side effects of dehydration is constipation. Drink more water to encourage the transit of waste through your digestive system and help soften stools. It should also make you feel less bloated (9).
Water may give you healthier skin
If skin cells are starved of water they start to whither and shrink. Drinking more water will make the skin look clearer and plumped up and also reduce under eye puffiness. If you suffer with very dry skin or dry skin conditions like eczema, drinking more water can go some way to help alleviate symptoms.
Water may save you money
Buy a safe reusable water bottle and keep refilling it and you’re likely to save on buying soft drinks and bottled water whilst out or at home. Using a measured water bottle will also help you monitor how much of your recommended daily amount you are getting (10).
Fight off colds and flu with water
Medical experts recommend you get more fluids if you’re coming down with an infection like a cold or flu. Your body has to protect itself against the invading germs and your cells need more fluids to fight off the infection. All water will help but studies show hot water (with vitamin-C rich fresh lemon juice) appears to be more effective than cold if you already have symptoms of an upper respiratory infection like a cold or flu (11).
Drinking more water could result in fewer headaches
A headache can be the body’s warning signal that you are dehydrated. Dehydration also appears to be a trigger for migraines and tension type headaches (12) (13). If you are prone to headaches try upping your water intake to see if your headaches become less intense and less frequent.