The standard recommendation of water intake for children is at least 6-8 glasses (1.5 - 2 liters) a day, drunk regularly throughout the day (at least 3-4 glasses while at school) ensuring that plenty of additional fluid is drunk during warm weather and/or when exercising. "When exercising" means before, during and after exercise and is not restricted to formal PE and games lessons, but is also applicable to active play (e.g. football in the playground or periods of running around).
The Institute of Medicine of the National Academies, Washington DC (2004), includes a separate category for teenage boys aged 14 over who require a higher average fluid intake of 2.6 liters (about 11 large glasses).
Pupils spend at least half their waking hours in school. During this time, they should be drinking at least half their daily requirement, spread regularly throughout the day. Readily available Water Coolers strategically placed around school premises can help to achieve these aims.
What is dehydration?
Dehydration is simply not having enough water in your body. It may result from inadequate water intake and/or from losing body water and can develop rapidly or slowly.
How can you tell if children are dehydrated?
A lot of people don't even realize they are dehydrated because they have become so used to feeling below their best.
Symptoms of mild dehydration can be difficult for teachers to spot. In class some children may become irritable, tired and less able to concentrate. By the time they get home many children are complaining of tiredness or headaches and some may be too lethargic to do anything but slump in front of the television. Although we may think of this behaviour as normal, it is now known that it may, at least in part, be due to the effects of dehydration.
Children can be taught to recognize when their fluid intake is too low as the urine becomes concentrated (small amounts of deep yellow, cloudy, smelly urine). If their urine's no darker than the color of pale straw, odorless and copious they're doing OK.
What effect does dehydration have on the brain?
Water makes up about 80% of the brain and is an essential element in neurological transmissions. Poor hydration adversely affects a child's mental performance and learning ability. Symptoms of mild dehydration may include tiredness, headaches and a feeling not unlike jet lag, as well as reduced alertness and ability to concentrate. Mental performance including memory, attention and concentration can decrease by about 10 per cent, once thirst is felt. Mental performance deteriorates progressively as the degree of dehydration increases.
Thirst is usually felt when dehydration results in 0.8 - 2 per cent loss of body weight lost due to water loss. For a 10-year-old child weighing 30kg this is equivalent to one or two very large glasses of water (300ml each), which is the amount a child could lose during a PE lesson or running around in the playground. Water consumption also has an immediate alerting and revitalizing effect. In schools taking part in the Food in Schools water provision pilot project, the consensus from teachers was that "enhanced provision contributed to a more settled and productive learning environment, as well as helping to instil good habits". The key to boosting the capacity to learn is to keep well hydrated throughout each day (ideally from a personal water bottle within arm's reach).
What are the effects of dehydration on children?
The early effects of even mild dehydration are significant for health, well being, performance and learning - and in the long term carry a higher risk of a number of health problems and disease states. These include constipation, continence problems, kidney and urinary tract infections, kidney stones, and some cancers. In some scientific studies, a decrease in cancer risk was specifically associated with water, as opposed to any other fluids.
Encouraging pupils to drink water during exams, but not during normal lessons the rest of the year?
We have heard many reports of this happening in schools. While we normally welcome initiatives to promote drinking water during the school day, doing so for just one or two weeks seems to imply that the school doesn't have concerns for the health and well being of the pupils in their care during the rest of the long school year, which, we hope, would not be the case in any school. Drinking water regularly throughout the school day makes healthier pupils who in turn make better learners. Exam results are not determined by performance on the day alone.
Children need to be adequately hydrated during all school lessons in order to maximise their learning potential. By the time a child feels thirsty, their mental performance may have deteriorated by 10% - attention, concentration and memory are all adversely affected. Furthermore, it normally takes a few weeks for bladders to adjust to an increased water intake so introducing increased water consumption at the start of exams is not very helpful! There are definite benefits to encouraging pupils to drink water during exams, not only improving performance but also helping to cool them down and reduce stress levels, but pupils should be drinking water regularly during the school day throughout the rest of the year too.
