Why We Should Drink Eight Glasses Of Water Each Day
Normally, approximately 2.5 litres of water is required daily for a fairly sedentary adult in a normal environment to replace the total loss of water that occurs though urine, faeces, skin and lungs.
This water loss needs to be replaced. One litre or so needs to be as water or other non dehydrating fluids such as cold herbal teas. A little under a litre will come from food intake. The body also makes about 300ml through its own oxidative metabolic processes.
If you don’t drink enough water, this is what happens.
1. Pulse rate and rectal temperature increases
2. Increase in respiration
3. Tingling and numbness of fingers and feet
4. Increase in concentration of the blood
5. Reduced blood volume and more difficult circulation of the blood
The difficulty and problems of the blood circulation under such conditions leads to:
1. breathing difficulties
2. gastric upsets
3. feelings of sickness and not wanting to eat
4. if it continues, muscular and emotional problems
In a scientific study involving animals, the restriction of water gave rise to irritabliity and for some, bad temper.
Thirst
It has been demonstrated that under intense physical activity a male will only drink voluntarily around 50% as much water as what is required to replace losses from urine and sweat. Only after rest and food do the cravings for the required amount of water return to replace the fluid deficit.
Hot Drinks
Ingestion of hot drinks may cause internal body temperature to rise, which will result in sweating in order to cool the body down. Hot drinks are sometimes used in medical practice when it is desired either to temporarily increase body temperature of induce sweating. Therefore cold or cool drinks are preferred to hot drinks to replace fluid during the day, especially if the hot drinks are the only fluid daily intake.
Drinks containing sugar
During periods of physical activity that last under an hour and a half, water is the preferred choice. However drinks that contain a small amount of carbohydrate can sustain power better than water alone during activities that would create fatigue in an hour or longer.