Hydration

Our body is up to two thirds water – that's 42 litres of water in a 70kg person! So it's little wonder that water is crucial to the function and metabolism of our body. We can't survive more than afew days without it, yet we can last for several weeks without food. Despite the importance of water, many of us don't drink enough to maintain an adequate level of hydration. Part of the reason isthat our thirst mechanisms don't tell us we're thirsty until we're already quite dehydrated. It's easy to spot some of the symptoms of dehydration, things like headaches, a dry mouth, bad breath, lowenergy levels. It doesn't take much, even a degree of dehydration as low as one or two per cent can affect your ability to exercise. So if you're feeling that you can't push through your evening workoutwith the normal intensity, have think about how much you've had to drink. It could be as simple as being dehydrated.

Fluid Balance
The fluid balance in our bodies is pretty easy to determine.There's water intake, from drinks and food, and water loss from going to the toilet, sweating, breathing, and evaporation from the skin and lungs. The general recommendation for fluid intake is eightglasses of water a day. But how much we need to drink differs from person to person, depending on how much fluid we're losing. Any situation that increases water loss from our bodies increases our needto drink. So if we're sweating from exercise or hot weather, if we're in a sauna or hot tub, or if we're sick with a fever, vomiting or diarrhoea, we need to up our intake. There's a simple way tocheck if we're getting enough fluid: have a look at the colour and frequency of your urine. It should be very pale, almost straw-coloured, and we should urinate frequently throughout the day. Dark urineand long periods without going to the loo are sure signs of inadequate hydration.

Water
Without doubt, good old H2O is the best drink choice. Water contains zero kilojoules and unless you're...