Staying hydrated: How much water should I drink a day?
Believe it or not, it’s one of the questions I’m asked most often and the truth is, there is no set answer – but one thing is for certain: staying hydrated is essential for the body’s homeostasis (the body’s need for stability).
Usual health advice claims that eight glasses a day should be the norm – but that’s hard to back up, not least because who knows how big a glass they mean? Eight pint glasses would obviously be twice as much water as eight half-pints!
Then you have to take into account things like body weight, whether male or female and how much you exercise.
The best calculation I have come across is 0.03 litres for every kilogram of weight. So if you weigh 60kg, the amount you should drink would be: 60×0.03 = 1.8 litres
That’s actually about eight half-pint glasses, so the old adage has some truth in it – as long as you weigh 60kg.
If you want an old money calculation, it is 0.5 fluid ounces per pound – and there are 20 fluid ounces in a pint.
And if you exercise, you probably want to take on another half litre per half hour of exercise – although this should preferably be in the form of a sports drink.
That’s a lot. How do I, er, stop peeing?
Well that’s a good question – but going to the loo is one clear sign that you are drinking enough water. Your wee should be the colour of light straw to ensure it is flushing out the toxins it should be, darker and you need more water, lighter and you need a bit less.
The best way to avoid constantly going to the loo though is to just pop a dash of sea salt into one of the glasses – and make sure you drink the lion’s share of your water (around 60-70 per cent) before noon.
Does it HAVE to be water?
The good news is to stay hydrated, it doesn’t have to be all water – other fluids: tea, coffee, milk and soft drinks do count. But do not use these as a total replacement for water… There is an excellent list of the pros and cons of all drinks on this NHS web page.