According to common wisdom – and lots of A-list celebrities – the answer is “a whole lot”. Water regimens (eight glasses a day, or six, or three before lunch and five before bed, etc) have been credited for everything from weight loss to perfect skin.
Fortunately for those of us losing sleep over our hydration, modern water lore is based mostly on hearsay and pseudo-science. So what are the facts on H2O? And how much do you really need?
Disclaimer: Hydration is extremely important
Okay, so this post may explain why we don’t really need to binge on gallons of water. On the other hand, dehydration is really bad. Around 60 per cent of the human body is made up of water, and not getting enough can cause fatigue, headaches, dizziness and confusion in the short term. Unless you rehydrate, you’re facing a grim scenario of delirium and death.
It is especially important to go out of your way to hydrate in the following circumstances:
- Hot weather
- Periods of physical labour or exercise
- Pregnancy or nursing
- If your urine is a deep yellow colour
That being said, the rest of this post will address an ordinary day when you aren’t spending lots of time outdoors in the heat or training for a marathon.
Excess water doesn’t really do anything special
The old “eight glasses a day” adage, as well as most “doctor recommended” regimens that require seemingly constant water consumption, are usually myths that give the appearance of some scientific basis (of the same ilk as “we only use ten per cent of our brains”). They’ll promise everything from detoxing to weight loss to cancer prevention, and are especially attractive because they don’t require exercise, dieting or any effort beyond perhaps carrying a water bottle around the office.
So what do the real scientists say? Apparently, the best strategy is to simply to drink when you feel thirsty.
Yes, each person typically requires a certain amount of water per day (about 3.7 litres for men and 2.7 for women), but the adult body is good at regulating its own hydration, and yours will likely let you know if it’s time to tip back a tall glass of H2O.
That said, while over-drinking is technically a thing – there have been incidents of people going to the hospital or even dying from extreme binge drinking – following the eight glasses a day program or another water regime is unlikely to do any harm.
What if you don’t feel thirsty, but also don’t drink much water?
Water is found in all sorts of places. Indeed, many of the foods you already eat contain lots of water (most of us get 20 per cent of our fluid intake from food, according to the Mayo Clinic). Additionally, most drinks, including milk, tea, coffee and soda, are made up mostly of water.
Contrary to popular wisdom, caffeinated drinks can still hydrate you. Although caffeine can cause some diuresis (increased need to urinate), it is not usually severe enough to cause a net water loss. Alcohol, on the other hand, has a much more severe diuretic effect, and drinking too much can cause dehydration.
Are sports drinks healthier than water?
Sports drinks like Pocari Sweat and Gatorade are mostly water, but they bring one key component to the table: electrolytes like potassium, sodium and magnesium that dissolve into the water in our bodies and help facilitate electrical impulses, especially within the brain.
The body loses a lot of electrolytes when it sweats, so it is important to replenish these when outside in the heat or during exercise.
That being said, most sports drinks are also loaded with sugar, which is not healthy. Better choices include coconut water, special kids’ electrolyte formulas at pharmacies or a DIY electrolyte drink.