WATER: Are you getting enough & how much is enough?
Health & Fitness By KEMI ILORI
Tuesday, October 2, 2007

Last week, I took time to explain what energy and sport drinks are, their content, etc. The bottomline where fluids are concerned is that we should get enough water for proper hydration. Some drinks, like energy drinks are highly concentrated and can be dehydrating. Today, we will look at how much is enough. In normal temperatures, the average sedentary person should drink at least eight glasses of water a day. Warm weather and exercise place even higher demands on the body for fluid.

How do you know when you need to drink water? During the course of everyday, we loose fluids through the skin as sweat, through the lungs during breathing, and in the urine. During physical activity, we loose fluids more rapidly than when we are inactive. Replacing those fluids is important when engaging in any type of physical activity, whether it is scrubbing down a house, mowing the lawn/ cutting grass, playing a game of soccer, cooking or participating in more irregular activities like the MTN maraton.

Experts agree that consuming adequate fluids before beginning a physical activity is a must. In addition, consuming fluids throughout physical activity is very important. These way, we reduce the risk or dehydration by rehydrating continually. Thirst and urine can be indicators of when we need to replenish body fluid:

Thirst: The average person uses thirst as his means of identifying that he needs to drink water or rehydrate. Do not rely on thirst as an indicator of your body’s need for fluids. By the time you’re thirsty, you’re already dehydrated! In fact, as we age, thirst becomes an even poorer indicator of the body’s fluid needs; so adequate fluid replacement is especially important as we get older.
Urine: The most reliable indicator of hydration status is your urine. If your urine is dark and there is not much of it, you’re dehydrated and should increase your fluid intake. Drink fluids until your urine is pale yellow/clear and plentiful.

In general, drink small but regular amounts both before, during, and after exercise. Frequently drinking small amounts usually works better than drinking a large amount once or twice. Make sure that you drink enough of water.

Dehyration: Weight loss in a good indicator of how much fluid has been lost by an individual. In marches, marathons and long treks, participants should be weighed before and after the event. These days, a lot of celebrity walks are pronounced for various things, e.g. World AIDS Day, Workers Day, etc. A simple activity like weighing participants can help to get them properly rehydrated during and after the event. Dehydration of eight percent is equivalent to a loss of four kilogrammes through sweat for a 50kg runner, or 5.6kg for a 70kg runner.

What are the fluid choices for rehydration? Water is the base in which the contents of most drinks are dissolved. As a result, when we drink beverages/ drinks, we are also taking in water. Unfortunately some of these drinks increase our body demand for water because they contain a high concentration of substances that may be injurious to our body e.g.kidneys, heart, etc. For example, abuse of sports drinks may result in adverse effects.

One case of potassium-induced ventricular arrhythmia has been reported in a football player who consumed about five grammes of potassium per day of a hydrosaline drink! He was lucky this happened in the Western world where the cause of his problem was quickly traced. Water is the best fluid of choice, but fruit juices (especially natural ones), smoothies, seltzer waters, lemonade, soft drinks, milk, and herbal teas are also good; especially if they are dilute. Try to avoid oversweetened, carbonated and caffienated drinks.

Water: Can you overdose? Nature is about balance. Excess of anything is dangerous; even water. Like most things done to an extreme, you will want to avoid over-consumption of water, also referred to as "water intoxication". Overuse of water can result in hyponatremia, a condition where too much water actually dilutes the body’s sodium levels. This condition used to be considered as rare. But in more recent history, it has been observed that some athletes may overhydrate. This is due to the erroneous impression that water is safe and that they need to drink plenty of water. A reasonable approach for these athletes is to drink no more than required, rather than as much as possible. A tragic event in 2002 shows that you can overdose on water! This was the death of a female runner during the 2002 Boston marathon.

The athlete, who died of hyponatraemic encephalopathy (swelling of the brain caused by severely reduced blood sodium), had reportedly ingested excessive amounts of fluids before and during the race. Meanwhile, recent reports in the medical literature seem to confirm a trend that marathon medical experts have observed: hyponatraemia has become increasingly common with the increasing participation of recreational athletes in endurance events.

The possibility of such occurences are at our doorstep. People need to know what limits are necessary for safety and good health in everyday life and recreational sport events, like marathons e.g. the MTN marathon. Do not just jump up and take part in these events without knowing what your state of health is and how to conduct yourself during the exercise. That is what articles like these are about. Imagine a situation where a participant/athlete collapses in a marathon. How do you know if it is from heat or over-hydration? A specialist, Professeur Tim Noakes, points out that confusion between hyponatraemia and heat illness can be very dangerous at the site of collapse, since the latter condition tends to be treated by administration of intravenous (IV) fluids, which are bound to exacerbate an already life-threatening situation, i.e. forcing more fluid into the system of someone who is already overdosed!!

In such an emergency, a quick measurement of rectal temperature (this can be done by inserting a thermometer into the anus of the victim), can help to differentiate between the two possibilities. Measurement of rectal temperature and plasma sodium concentration should allow for accurate diagnosis. And Noakes argues that if rectal temperature does not exceed 40oC at the time of collapse, heat illness is not to blame and IV treatment should not be offered. In a place like Nigeria, the rectal temperature will be a quick way of preventing the administration of IV fluids, whilst the patient is evacuated to a more appropriate loation like a clinic or hospital.

For normal everyday life, in a tropical climate like ours, 1.5 to 2 litres of water a day should be a minimum individual water intake for an adult.