Hydrate or Die

by Margot Hurrell

We all know that water is important.

Hydration (drinking adequate fluid) is a critical part of outdoor exercise and experience, whether you are bushwalking, climbing, skiing, mountaineering or paddling. Whenever you are exercising you can lose a substantial amount of fluid. Dehydration contributes to fatigue and may make you more susceptible to shock, cramps, heat exhaustion and heat stroke. I have perused the literature and collated what seems to be the current theory on hydration and whether to use electrolytes or not and what about those sports drinks? Remember, no matter what fluids you are taking, do NOT ever share your drinking bottle with others.

If you are thirsty, you are already dehydrated. It (thirst) is a poor indicator as it is a late signal of severe fluid loss. Other earlier signs and symptoms include: feeling dizzy, headachy and a little sick in your stomach. You can also tell if you are getting dehydrated by looking at the colour of your urine. If it is not "gin clear", then it's likely that you have fallen behind in on your fluid needs.

Dehydration has a significantly detrimental effect, causing:

- decreased concentration levels, leading to increased clumsiness
- decreased performance levels through increased fatigue and headaches

Plain water is appropriate for gentle to moderate exercise when suitable nutrition (with carbohydrates and electrolytes) is provided. Drinks containing 4-8% carbohydrate and 0.5-0.7g/litre sodium are recommended for intense exercise lasting longer than one hour ¾ particularly for continued sweat losses, vomiting and diarrhoea. Salt tablets are not necessary and can make the dehydration worse.

Hydration formula:
Drink 500mls (2-3 glasses) half an hour to one hour before exercise.

Drink 200mls (1-2 glasses) every 20 minutes during exercise (max 600 mls/hour).

Drink 500mls after exercise.

Drink cool water ¾ it is absorbed more rapidly than warm water. Good-tasting cool fluids are your best choices. You need to move the fluids from your stomach into the small intestines, from which they are absorbed into the blood stream ¾ cool (but not cold) water containing glucose or sugar accomplishes this process more quickly. If exercise is going to continue for greater than one hour consider sports drinks (a carbonated drink of 4-8 per cent concentration with the addition of a small amount of sodium).

Have you ever finished that long, strenuous bushwalk in hot, humid conditions and what you crave is fish and chips? This is your body's way of saying you are low on electrolytes. Electrolytes such as sodium and potassium are ions (electrically charged molecules) that are present in all body fluids. They maintain the body’s chemistry and allow the body to perform all its essential to life functions. As the body cools itself via sweat evaporation process, it secretes primarily water and electrolytes. As minor electrolyte imbalance occurs, there are symptoms of fatigue, exhaustion and mild mental confusion. Electrolyte imbalance can also cause muscle cramps or more severe situations such as hyponatraemia, a potentially life-threatening condition.

All sports drinks are not created equal. They vary greatly in the concentration of carbohydrates. A general rule is the more concentrated the drink, the more slowly it is absorbed.

When engaged in exercise people should avoid:

- caffeine, energy drinks (e.g. Red Bull, V), smart drinks and alcohol as these increase fluid losses
- shared drink bottles so that flu, hepatitis, meningococcal meningitis and other infections do not spread.

As children are less effective at sweating and produce more heat during exercise than adults, hydration and fluid intake are particularly important when exercising in hot/humid climates. Children may need to be encouraged to drink more fluids. (Flavoured and cool beverages are preferred).

Gastrolyte is the preferred electrolytre replacement fluid. Active ingredients include sodium chloride 0.47g, potassium chloride 0.3g, sodium acid citrate 0.53g, glucose 3.56g. Oral correction of fluid and electrolyte loss in infants, children and adults.

What about Coke as a hydrator?

Almost 90% of cola is carbonated water. Adding carbon dioxide to water produces carbonic acid which, although weak, can erode teeth. The active ingredient in Coke is phosphoric acid. Its pH is 2.8. It will dissolve a nail in about 4 days or a human tooth in 48 hours. To clean a toilet: pour a can of Coca-Cola into the toilet bowl and let it sit for one hour, then flush clean. You will be pleasantly surprised at the results. It's your choice!

Why not share those water bottles?

A spate of deaths from meningococcal meningitis has shone the spotlight on one of the last deadly infectious diseases to affect young people left in the developed world. Doctors say it is immensely difficult to diagnose and will infect several hundred people in Australia each year, probably killing about 10% of those who contract it. Thirteen people have died in New South Wales alone this year from meningococcal meningitis, more than last year. But, according to NSW Health Department's communicable disease director, Dr. Jeremy McAnulty, this is an average result for the last decade.

What is meningitis?

Meningitis, is an infection of the layers of tissue which cover the brain and spinal cord. It may be caused by many different germs. It is generally a very serious illness which can result in blindness, deafness, amputations, permanent brain damage, or even death. However, with proper treatment, many people recover fully.

What is meningococcal meningitis?

Meningococcal meningitis is a particularly severe form of meningitis caused by the bacteria Neisseria meningitidis. Even when treated with the right antibiotics, about 10-20% of people with this illness die, often within hours of the onset of the first signs. It is particularly dangerous for babies, children and young adults. It is contagious, but not as contagious as the common cold or flu. It is spread by direct contact, as in coughing, sneezing, kissing and immediate sharing of unwashed eating/ drinking utensils (e.g. water bottles).

What are the symptoms?

Symptoms of meningitis in adults may include:

- fever
- vomiting
- intense headaches
- stiffness of the neck
- a skin rash that looks like small, purplish, red spots
- experiencing discomfort looking at bright lights (photophobia)
- joint pain.

Any infant with a fever of 38°C or greater and who is not easily wakened should be seen by a doctor. People with meningitis may also be confused or very drowsy; sometimes they may even go into a coma from which they cannot be awakened. Unfortunately, the early symptoms are often indistinguishable from the common cold or influenza, and by the time the rash appears, which is characteristic of this particular disease, then it is often, if not usually, too late.

Incubation period

The period from contact with the bacteria to development of symptoms is usually two to four days, but may be as long as ten days. People of any age can carry the bacteria for days, weeks or months without becoming ill. People remain infectious as long as the bacteria is present in the upper respiratory tract (back of the throat and nose).

Adult management

Do not wait. This is an urgent evacuation and a medical emergency. The casualty must be hospitalised, almost always in intensive care. They are treated with intravenous antibiotics and other medications and monitored closely.

Is there a meningococcal vaccine?

The meningococcal vaccine is only effective against a few of the thirteen strains of the bacterium.

Short References

1. Drink Up: Smart Play, Sports Medicine Australia
2. Heat Related Illness by Eric A. Weiss, MD
3. New Zealand ACC Sports Smart: Hydration & Nutrition (pamphlet)
4. Meningococcal Disease Fact Sheet, Mid North Coast Area Health Service
5. Facts about Meningococcal Meningitis
6. http://www.tdh.state.tx.us/ideas/factsht/meningitis.htm
7. Meningococcal meningitis difficulties, ABC online, PM (25/7/2002)

Margot Hurrell is the managing director of The Safety Network. The Safety Network conducts remote area and wilderness first aid and safety courses throughout Australia and SE Asia.

Diseases transmissible through sharing drink bottles/tea towels

Pathogens Diseases

- Adenovirus Conjunctivitis (red-eye)
- Chlamydia trachomatis Trachoma
- Epstein Barr virus Glandular Fever
- Hepatitis A virus Acute hepatitis A (mainly through lack of personal hygiene)
- Hepatitis B virus Hepatitis B (low risk of transmission via such routes)
- Herpes Simplex type I virus Cold sores
- Norwalk-like viruses Diarrhoeal illnesses
- Rotavirus Diarrhoeal illnesses (mainly in young children)
- Neisseria meningitidis Meningococcal diseases

In general, a lot of diseases are transmissible through close personal contact, e.g. viruses like measles, mumps, rubella, chickenpox, influenza (flu), common cold, Parvo B19 (slapped cheek syndrome).

Source: Dr. Sonny Lau, medical director, The Travel Doctor - TMVC Melbourne (www.traveldoctor.com.au)

This article is was first published in the February 2003 edition of Journeys

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