|THE MAGIC OF WATER||REEC HOME||Year 2-6 HOME||WATER CONTENTS|
29. What happens if I don't drink enough water?
Water is important because the body uses it for chemical reactions, nutrient delivery, waste disposal and temperature regulation.
For a person not doing much exercise an expected water loss would be approximately 2500 ml per day and would comprise:
Exercise greatly increases fluid loss which can reach levels of up to 4 liters per hour during heavy work-outs.
Blood plasma is 90% water so dehydration reduces the volume of blood in the body which makes the heart system work harder to pump the blood around the body and deliver sufficient oxygen to the working muscles. Exercise feels much harder as your body's systems aren't working as efficiently as they do with good hydration and performance is impaired.
Dehydration is defined as a 1% or greater loss of body weight as a result of fluid loss.
Early signs that you are mildly dehydrated may include light-headiness, dizziness, irritability and headaches.
As you get more dehydrated the symptoms get more severe and can lead to clumsiness, dim vision and exhaustion. When dehydrated your attention and concentration can decrease by 13% and short term memory by 7%.
As dehydration progresses, nausea and vomiting may be experienced and by 5% reduction in total body weight, performance has dropped by 30%. Fluid losses greater than this lead to coma and death.
Don't rely on thirst as an indicator of dehydration. By the time you feel thirsty your body has lost between 2 and 5 cups of water! Drink water when you get up in the morning, at breakfast, play lunch, lunch and tea. Drink before, during and after any physical activity.
Based on an article for Yarra Valley Water by Karen Hambly www.yvw.com.au/yvw/Home/TAPHealth/DehydrationandYou/
How does the colour of your urine change after a lot of exercise or on a hot day? Explain this.
Riverina Environmental Education Centre