Drinking eight glasses of water a day is probably a mantra that has been drilled into you from a young age.
More often than not, the number eight is really just a rule of thumb, a figure that is easy to remember. The question of how much water you should be consuming in a day has no straightforward answer, since there isn’t an exact formula to determine how much you body needs to stay hydrated. Instead, there are several other factors in play, like your general health, how active you are, the climate, and what you eat.
Drinking sufficient water helps prevent constipation, leaves your skin feeling supple and is essential for the regulation of vital systems in your body, for example, blood circulation, metabolism, regulation of body temperature and so on.
Listen to your body
The human body is actually finely tuned and will signal you to drink when you need it – so listen!
Once your body has lost about one to two percent of its total water content, it will signal to you to drink. However, by the time your thirst mechanism kicks in, you're already in the early stages of dehydration, so you should not ignore the initial sensations of thirst.
The elderly and children are more vulnerable to dehydration as their thirst mechanisms are less sensitive, so parents should pay special attention to the water intake of their kids.
Not all your fluid intake comes from water
Not all of your fluids are derived from drinking water. Some of that 'eight glasses' is also consumed through food, like fruits and vegetables, soup or porridge, and other beverages such as milk.
Check your urine
Concentrated, dark-coloured urine is a strong indication that you need more water. It means that your kidneys are retaining fluids to maintain your body functions.
To monitor hydration, look before you flush. Your urine should be a light-coloured yellow, like lemonade. If it’s darker, you should make an effort to drink more water.
Frequency of urination is another indicator. Healthy individuals should be able to pee at least four times a day.
When you drink too little…
Research from Loughborough University indicates that being behind the wheel while you are dehydrated is just as hazardous as being under the influence of alcohol, as those who drive dehydrated apparently make twice the number of mistakes than those who drink enough water.
Being dehydrated can cause fatigue, dizziness, mood swings, headache, foggy thinking and poor concentration. Even mild dehydration can drain your energy and leave you feeling tired.
When you drink too much…
While you want to stay hydrated, you do not want to be overhydrated either.
If we drink more water than your kidneys can process, it dilutes your sodium levels. This causes hyponatremia or water toxicity.
Some symptoms of hyponatremia include feeling hot and having a headache. When untreated, it can lead to more severe symptoms such as muscle weakness, nausea, vomiting, and in some serious cases, even a coma.
The British Journal of Sports Medicine found that many athletes are actually at risk of exercise-associated hyponatremia due to their decision to drink too much.