Where the purity of water supplies is unreliable, distilled, bottled, or de-ionised water should be used, rather than that from the tap. At times of vigorous physical activity, or increased emotional stress, more water is needed to overcome the dehydrating effects of the activity or stress. Everyone interested in improving their brain function as well as their general health should consider getting the majority of their liquid intake in the form of water. Energy comes from food, but the ability to make good use of this energy comes from keeping the body well hydrated. Efficient mental and physical function relies on water being available to all body and brain cells.
Students do better in tests and examinations when they drink water through study sessions.
A glass every hour and a half is good. Frequent sipping from a drink bottle with a sipper is a method some people are finding useful. People perform better in examination rooms when they have had a glass of water beforehand. It should be noted that pure water does not increase urine production nearly as much as coffee, tea, or alcohol. Schools and universities are starting to allow examinees to take a water bottle into examination rooms for the same reason that long distance runners and cyclists are encouraged to take water during racing.