Dr Emma Derbyshire, advisor to the Natural Hydration Council, gives her tips for keeping hydrated this summer…
Water is essential for health and wellbeing, forming about 60 per cent of our body weight. Women retain slightly less water due to higher levels of body fat, which stores less water. Some of the key roles of water include helping to transport nutrients around the body, removing waste products, regulating body temperature and acting as a shock absorber, especially during exercise.

There is often confusion about how much we should drink. European guidelines advise that adult females should aim to have two litres of fluids daily and adult males two-and-a-half litres. These differences are mainly due to men having a larger body mass, less body fat and higher sweat rates than women.

The guidelines about how much to consume don’t just refer to ‘drinking’. The fluid we consume should come from both food (about 20 to 30 per cent) and drinks (around 70 to 80 per cent). Despite most people knowing they should keep hydrated, evidence from a UK Fluid Intake Survey, made up of 1,456 adults and children, found that 30 per cent of adults and more than 50 per cent of children did not meet the European adequate intake for total water/fluids. This is a concern, given that studies have shown that dehydration can be linked to reduced cognition (mental wellbeing) and also affect mood, especially among those with poor fluid regulation, such as children and the elderly.


For those who are active, it is important to drink enough fluids before, during and after exercise. For most people water is all that is needed to hydrate when exercising. Sports drinks tend to be misused, particularly among young people. According to research by the American College of Sports Medicine, sports drinks are only really needed for high-intensity exercise lasting for more than 60 minutes. Sports drinks can provide extra energy, enhancing performance under the right conditions, but for most of us this is not needed, as generally, we exercise to lose weight.

Finally, whether you are out and about pursuing normal daily activities in warmer weather, or exercising, some telltale signs of mild to moderate dehydration (a one to two per cent reduction in body weight) include muscle tiredness, headache, reduced urine output and dark yellow or brown urine. So stay aware and keep topped up.

Dr Emma Derbyshire is senior lecturer in nutritional physiology at Manchester Metropolitan University.

Essential tips

  • Drink water at regular intervals throughout the day.
  • Bottled water is handy when you are on the move, or exercising.
  • Quench your thirst with water before drinking other beverages such as tea, coffee, squash and fruit juices.
  • Remember that foods containing water can contribute to your daily fluid intake, for example soups, stews, fruit and vegetables.
  • Drink more when you exercise or spend time in hot environments, eg, warm offices or travelling.
  • Sip water in small amounts before, during and after exercise.
  • For most light exercise, including swimming, golf and walking, water will rehydrate you adequately.
  • Sports drinks may only benefit those undertaking high-intensity training lasting for more than one hour.
  • Replenish fluids regularly, especially when sweat rates are high.