Water

Secondly only to oxygen, water is the most necessary compound for life. We can go weeks without food but only days without water. Consider the following: blood is 83% water, kidneys 82%, muscles 75%, brain 74% and bones 22% water. It is much easier to become dehydrated than you think. The average person will lose about 1 litre of water per hour of exercise. When you exhale you lose water. When you blink, a watery solution is passed to the upper eyelid to lubricate the eyes and is then passed down to the nose where it will evaporate. Not to mention the more than 2 million sweat glands you have that excrete perspiration, which is 99% water.

Dehydration will also result in thicker blood, making the heart work harder and delivering less blood and oxygen to the brain. Kidney dehydration forces the liver to remove toxins, making the liver less effective in the metabolism of food. Water is also stored alongside your glycogen stores. When your water levels are low, the glycogen will remain in the blood until it reaches the liver and is then stored as fat. Dehydration will make you fat. Dehydration will cause your body to retain water, causing you to feel bloated and giving you a "soft" or "puffy" look.

A 2% loss of body water will result in a 30% reduction in performance. An 8% loss of body water will result in a 30% reduction in performance along with nausea, diarrhoea, weakness and confusion. Generally, you should be drinking between 1.5-2 litres a day. Buy your water in 2 litre bottles and drink from that. Trying to count small bottles of water or glasses of water throughout the day just doesn't work. Don't be alarmed if you find yourself going to the bathroom a lot or if you have discoloured urine, this will all subside in good time. It's more a reflection of just how dehydrated you are.