“The Physiological Importance of H2O”
It is important to drink water. Water can act as a lubricant in the muscles to ensure frictionless movement. A person can go for days without food but three days without water is enough to kill. Dehydration can damage the immune system, causing a person to become sick. Dehydrated people can become clumsy, sluggish, and they can faint. Some common signs of dehydration are:
· Thirst. It is important to drink water before becoming thirsty, because if a person is thirsty, they are in the first stages of dehydration.
· Dizziness. Exercising for a long time without water can result in dizziness. It is important not to push yourself too hard.
· Confusion and/or fainting. These are the first signs of heat stroke. Heat stroke is cause by a high elevation of body temperature. This is why it is important to keep hydrated. Drinking water can keep the body at a normal temperature.
The human body is over 60% water. That’s over 2/3. But the water in our bodies is not just water. It contains electrolytes, which are salts, particularly ions. There are several different electrolytes in the body:
· sodium (Na+)
· potassium (K+)
· chloride (Cl-)
· calcium (Ca2+)
· magnesium (Mg2+)
· bicarbonate (HCO3-)
· phosphate (PO42-)
· sulfate (SO42-)
While exercising, the body loses water and electrolytes through sweat. It is important to replenish not just the water, but also the electrolytes. This is why athletes drink a lot of sports drinks. Sports drinks contain electrolytes. Drinking just pure water may not be enough. Electrolytes are important because they are what cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells. The kidneys work to keep the electrolyte concentrations in the blood constant despite changes in the body. For example, when a person exercises heavily, they lose electrolytes through sweating, particularly sodium and potassium. These electrolytes must be replaced to keep the electrolyte concentrations of the body fluids constant. So, many sports drinks have sodium chloride or potassium chloride added to them. They also have sugar and flavorings to provide the body with extra energy and to make the drink taste better.