Water – Why It’s Good To Drink 8 Glasses A Day
Around about 2.5 litres of water is required on a daily basis for an adult to replace fluid losses that occur through the feces, urine, skin and lungs.
To replace the water loss about 1 to 1.2 litres needs to be in drinks, (mainly water or cold herbal teas), 0.9 ml is taken though food and 0.3ml will be made by the body (oxidative metabolism).
If you don’t drink enough water, this is what happens.
The pulse rate goes up and there is an increase in the rectal temperature
Increase in respiration
Tingling and numbness of fingers and feet
Increase in blood concentration
Lessening of the blood volume and more difficult blood circulation
Problems and inadequacies of the circulatory system under conditions of inadequate fluid intake leads to:
breathing difficulties
gastro-intestinal upsets
feelings of sickness and not wanting to eat
if it carries on for an extended period it will cause problems with muscle movement and unstable emotions
In an animal study, where water was restricted the animals were highly irritable and in some cases bad tempered.
Thirst
Under a great deal of physical activity it has been demonstrated that a man will only choose to drink half of the water intake needed to replace losses from sweat and urine. It takes a period of rest and a meal for the cravings for water to return to replace losses.
Hot Drinks
After drinking hot liquids, the internal temperature of the body rises, resulting in sweating. This cools the body down. This is sometimes used in the practice of medicine when an increase in body temperature is required for a short time, or whether sweating is required. So it is preferable to choose cool or cold drinks rather than hot ones to replace fluid losses, particularly if hot drinks are the only types of drinks that are normally chosen.
Sugar drinks
Water is the preferred choice of liquid for physical activities that last less than 90 minutes. For activities that would create fatigue after an hour or so, drinks that contain some carbohydrate are better for sustaining power output than water alone.