What happens if you go without calcium for a week? You may get white bits on your fingers nails...
What happens if you go without water for a week? You drop dead. That's right, dead; As a block of wood.
The most important nutrient known is undoubtedly water. Well, not the most important maybe, because most nutrients are essential, but you can go a long time without most nutrients. A week is your absolute limit without water. Any longer than that and it's game over for you. I don't mean to scare you, but I'm just putting the importance of water in perspective for bodybuilders and everyone!
So why is water so important?
For a few reasons really. The human body typically consists of between 60% and 75% water. In the body, water's responsibilities include removing waste material from the body and moving other nutrients around the body. It also keeps your body temperature correct, for example the loss of water from the body (sweating) is the bodies way of keeping you cool.
How much water do I need?
The average human adult needs AT LEAST 8 glasses of water per day, but a lot more water is recommended. There is no stereotype person. Some people will need less than 8 glasses, some will need more, but on average, you probably need more. If you were to join the army, you would learn that you can tell if you're drinking enough water by the color of your urine. If it's dark, then you need to increase your water consumption. If it's clear, then you're drinking plenty. Sorry for that, but it's pretty important. Especially to athletes and bodybuilders.
When should I drink?
All the time! Thirst is your bodies way of telling you that it needs rehydrating, but you should really not get to the stage when you are thirsty. Drink as often as you can. Also, if you do feel thirsty, drink lots - not just enough to wet the inside of your mouth. You should also drink water before, during and after exercise. You should start drinking more water about 2 hours before you exercise (bearing in mind that your body can only absorb 1 glass of water every 20 minutes) and keep drinking right up until you exercise. Whilst exercising, sip water every few minutes. I drink water between every set. DO NOT wait until the end of your exercise period and then gulp down lots of water as this is not good for you.
Do I HAVE to drink water?
I always do, and I recommend bodybuilders do because there is no extra nutritional content (like there is with carbonated beverages, cordial mix drinks and all other unnatural liquids). But the answer, actually, is no. You can drink those things if you want. Coffee is a good pre-workout drink, as is Lucozade (It's a UK Gatorade thing I think). I realise that some areas (like where I live) the tap water is pretty horrible. It tastes of chlorine because that's what they disinfect it with. I like to drink bottled water, but some people have water filters to filter out the horrible taste, and I think they work pretty well (e-mail me if you know please!)
Anyway. the bottom line is this: Drink plenty of water and you'll be fine.
Oh, and on a side note, the first woman to ever complete training for the Royal Marines Commando all arms course (an 8 week course, not the full 30 week one) has failed the final tests.