How do you know how much water to drink?
Yesterday was a scorchingly hot day in Normandy - about 31 degrees in the shade, which made it the hottest May day since 1953, according to Meteo France.
A good day, then, to decide to do a 7km hike? Well, maybe not. I'd planned a riverside walk, through woods, in the shade, but a field of cows and my dog wasn't good combination, which meant a detour down some very hot, dusty, unshaded roads in full and blinding sunlight in order to get back to the river.
Nevertheless, we ended the day feeling fine and the reason was that we had enough water. A litre (with a little salt) on each of us, and another two in the car.
How much water do you need?
The worse advice I was ever given, about 15 years ago, was to only drink when I was thirsty. I've got used to simply ignoring thirst - I simply don't recognise it when it occurs. If I only drank when I was thirsty, I'd never drink at all.
And telling someone 'eight glasses a day' isn't much help either. Assuming that's an 8oz glass, that's 64oz of water a day. But not all people, whatever their weight or lifestyle or location, need this exact same amount of water.
Better methods are to drink until your urine runs clear, or to calculate your needs by body weight then amend for lifestyle and diet. If you're not active, you need half an ounce per pound of body weight, and if you're active you need more, which means that at my current weight, 133 pounds, and only moderately active, I would need 8.3 glasses of water per day. That equals 1.8 litres.
Unfortunately, I know from bitter experience that if I drank this little water, I could kiss goodbye to a bowel movement for EVER. The causes are that I like a glass of wine with meals, I have coffee for breakfast, I walk a brisk 3 miles every morning and I follow a high-fibre diet. All of these things mean I need more water.
You too may need more water if you do ANY of the following:
* Live in a hot climate.
* Eat high-fibre foods such as wholewheat.
* Eat dried foods such as dates and raisins.
* Eat a lot of cheese.
* Eat a lot of starchy foods such as root vegetables.
* Take daily exercise that makes you sweat.
* Drink alcohol or caffeine.
* Take saunas or steam baths (this one is never listed, but they make you sweat - you need to replace this lost water).
As you can see, the average Western lifestyle might lead to you needing more water than you might realise.
Signs you may be dehydrated are:
* Headache. At the first sign of a headache, try a good glass of water rather than a painkiller.
* Unspecfic pain such as low back pain.
If you have any of these symptoms, start first by modestly increasing your water intake by half a litre a day. Don't overdo it, as your kidneys need time to adjust to the extra work they'll have to do. The main reason people have become ill from too much water is drinking too much at one go.
What if you hate drinking water?
On the bright side, 'water' can be found in forms other than 'water' as such. Fresh fruits and vegetables are generally pretty high in water, especially above-ground veg such as salads, broccoli, cauliflower, peppers, courgettes and aubergines. Herbal teas can count towards your water intake because they don't contain caffeine, and so can modest amounts of fruit juice (that word was 'modest'). But don't count drinks with caffeine, or fizzy drinks (sodas). In fact, if you can, cut sodas out of your life - your body will thank you for it.
Obviously, 'wet' meals such as soups and stews have a lot of water in too. But if you follow a diet of white-bread cheese sarnies and chips with a beer, watch out...
How to work it out
It took me some time to work out a method of water consumption that worked for me, but here it is.
* I calculated my needs by body weight = 1.8 litres.
* I added up the things in my lifestyle that can cause dehydration and there were three major ones: exercise; high-fibre diet; alcohol/caffeine intake.
* For each factor, I added back in half a litre of water.
Total = 3.3 litres of water. This is about what I drink a day 'as water', and it seems to work for me. Others may find they need more or less. But yesterday I drank over 6 litres because of the heat and I needed every bit of it.
How to get it down
Personally, I find plain water quite difficult to drink, and having sips during the day, as you're recommended to do, just doesn't work for me. I suffer from reflux, following a car crash, and if I sip all day, it gets much worse. Instead, I drink my water at set intervals throughout the day. I also drink it warm, which makes it easier to get down, and with a little cider vinegar added for both flavour and for health reasons (it's anti-inflammatory). It goes like this:
* On rising, two 400ml glasses.
* An hour later, following exercise, two 400ml glasses.
* Before lunch (about 12.30), two 400ml glasses.
* Before dinner (about 7.00pm), two 400ml glasses.
Total = 3.2 litres.
Plus, I drink:
* Water during
the day if I feel thirsty.
* After dinner, a pot of herbal tea.
* Nothing after 9pm at the latest (to prevent reflux).
This is the method that works for me, but I can't stress enough that people must listen to their individual body's needs. I drink a LOT of water for my body weight, and others may not need to. But if you suffer from constipation, or headaches, or back pain, do think first and foremost of drinking a little bit more.