Just Add Water

Bland, boring old water. Taste like nothing, doesn’t look anything special, and doesn’t really do anything sitting in your cup. Once it’s in your body, however, there is nothing boring about it! The body is made up of about 55% water by weight and you better make sure you get enough of it. Here’s why…

What does water do?

Water has a myriad of functions in the body, one of the most important ones, is in the blood. A large fraction of blood is made up of water and without it, blood wouldn’t be able to do all the important things you want it to do. Such as, transport oxygen and nutrients around your body, so that you can run, jump, play, and breathe!

Water is also heavily involved in the body’s thermoregulatory system. Sweat is lost from your body as water from within the blood. This water travels from your blood vessels to your skin, for cooling. Without this mechanism, sizzling summer days would feel a whole lot hotter.

Water is a precursor to plenty of other important bodily fluids, such as saliva, tears and urine. In fact, the involvement of water in urine and faeces, is important to the body’s ability to remove waste products. Without this water-dependant waste removal system, toxic compounds would accumulate and wreak havoc on the body.

Finally, water is required for almost all metabolic processes. This means that without water, our body would quite literally, just stop functioning.

How much do I need?

The current recommendation states that women should consume 11 cups of water a day, and that males should aim for 15. However, this is a very general recommendation and individuals water requirements can vary markedly on the account of many factors. Such as, climate, body size, physical activity, environmental conditions (for example air conditioning is dehydrating) and dietary intake.

These recommendations are built on the assumption that 80% of water is coming from fluid and 20% from food. Some foods with a high-water content include fruits such as watermelon and orange.

What happens if I don’t get enough?

It’s obvious that the consequence of lack of water is dehydration. When you don’t consume enough water, there are systems in place that help maintain a healthy balance in the body. Dehydration is detected by the body as low blood pressure. This is because dehydration causes low levels of water in the blood, reducing its volume, and therefore, its’ pressure. Detection of low blood pressure stimulates the release of a plethora of hormones that work to correct water balance and bring that blood pressure back up. This includes reducing urine volume and increasing thirst. In most cases, you’ll drink some water and water balance will be restored. In more extreme conditions (for example sporting in hot climates), a negative water balance will set in, as the hormone system is incapable rectifying the situation. At this point, the individual will experience fatigue, dry mouth, dizziness and head ache. In the most extreme cases, dehydration can result in a rapid and feeble heart rate, delirium and collapse.

What happens if I have too much?

While far less common than dehydration, water toxicity shouldn’t be forgotten. Drinking too much water dilutes the body’s electrolyte concentration. Hyponatremia (low sodium), is the most notable result. This is experienced as headaches, blurred vison and muscle cramps.

Water balance through the life span?

If you’re an adult/teen, congratulations! Your water balance mechanisms are in perfect order. You are least likely to experience water imbalance, provided you drink to thirst. Children and elderly, however, aren’t so lucky.

Children are most susceptible to dehydration for a couple of reasons; underdeveloped sweating mechanism, less able to dissipate heat and inefficient movement. For this reason, it is important to ensure clean, cool fluids are conveniently available to children, particularly when participating in sport. Interestingly, despite biology working against them, children have fewer heat illness incidents than their adult and elderly counterparts. This is likely due to their un-inhibited thirst. Adults who feel dehydrated might put off having a drink to finish their work etc. Children, however, when they feel thirsty, just drink. Perhaps adults could learn a thing or two from children about listening to and meeting their body’s demands!

Elderly individuals have decreased thirst sensation and generally poorer thermoregulatory functions. Therefore, the incidence of heat related illness in this population is high. Elderly, their care-takers, friends and family, should prioritise the consumption of plenty of fluids. One trick that might help in getting your gran to drink her 11 cups a day, is to flavour water with something they enjoy. For example, cordial, lemon and mint.

Water, is life. And this is no exaggeration. Aim to meet your water requirements every day, and keep a keen eye on your hydration status.


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