Water

5.2.4 Water

Water is essential for life. It is an inorganic compound made up of hydrogen and oxygen, and it is a major component of the body, making up as much as 60% of an individual's total weight. Water is the medium of all body fluids, including blood, saliva, digestive juices, urine, faeces, sweat and perspiration.

Water performs several vital roles:

• It plays an important part in the regulation of body temperature.
• It is a universal solvent.
• It bathes the body cells and keeps them moist, acting as a lubricant — including an important lubricant for the joints.

The body obtains water mainly by ingestion — water taken as such or as beverages like tea, coffee, fruit juices and aerated drinks. Other foods such as vegetables, fruits, milk, cereals and pulses contain water in an invisible form. It is important that clean, safe and wholesome water is consumed, in order to avoid water-borne diseases such as diarrhoea, dysentery and cholera.

Why water matters even more for a sportsperson. During exercise, water is lost rapidly through sweat as the body tries to cool itself, and electrolytes such as sodium, potassium and chloride are lost along with it. Even a small fluid deficit — as little as 2% of body weight — measurably reduces endurance, strength and concentration, and brings on early fatigue, cramping and a raised heart rate. Because thirst lags behind the body's actual fluid deficit, an athlete who drinks only when thirsty is usually already somewhat dehydrated.

Recognising dehydration early is a practical skill: dark-coloured, strong-smelling urine, reduced urine output, headache, dizziness, irritability and an unusually fast pulse are the common warning signs. The simplest everyday check is urine colour — pale, straw-coloured urine generally indicates adequate hydration, while dark urine signals a need to drink more. …