Our Mission: "To assist our clients in developing the best possible Safety System to meet their needs".

Dehydration - A Hidden Source of Fatigue


Written by Gordon Dupont

July 2000 - This article appears in the summer issue of "GroundEffects"

A couple of issues ago we talked about fatigue and how it was a problem that the industry vastly underestimated and that we vastly overestimated our ability to cope with.  Well now it appears that we have a further problem that both the industry and we are basically totally ignorant of.  Dehydration has the ability to induce fatigue and the resulting reduction in judgment – all without us even being aware of it.

 Lets Start With a Few Interesting Facts.

1.      Without water we can live about 3 days.

2.      Our body is made us of about 60% water (women a little less than men for some reason). 

3.      Our brain is made up of 85% water and requires a very narrow range of water content to remain at its peak.  

4.      We lose about 8 to 10 cups, or just over 2 liters of water per normal day through breathing, urine, perspiration and bowel movements.

5.      If working outside on a hot day we can lose about two pounds or one liter of water per hour.

 Some Lesser Known Facts

1.      Doctors now say that a whopping 75% of people don’t have enough water. I.e. they’re dehydrated.

2.      As little as 2% loss in water content begins to cause the brain to lose alertness and the body to feel fatigued.

3.      Two to five percent dehydration is considered mild but sufficient to influence how the body will react.

4.      Six to ten percent is considered moderate dehydration and is cause for immediate concern.

5.      Eleven to fifteen percent is severe.  Hospitalization and intravenous will likely be required.

6.      Beyond fifteen percent can end in death.

 What are the Symptoms?

Surprisingly, thirst is not at the top of the list of symptoms.  We depend on feeling thirsty to keep us from becoming dehydrated and it has been shown to be a poor indicator. 

Dr. Batmanghelidj, in his book “Your Bodies Many Cries for Water”, states that in over one-third of us,(37%) the thirst mechanism is so weak that it’s often mistaken for hunger.  It is often only when we are moderately dehydrated, (6 to 10%) that we begin to pay attention to our thirst.  By that time our mental alertness has dropped dramatically and we are not even aware of it.

Here are some of the most common symptoms or indicators of dehydration.

1.  Lips and later mouth feel dry

2.  Heart rate and breathing increases

3.  Blood pressure begins to drop

4.  Begin to feel fatigued

5.  A nagging headache may develop and become progressively worse

6.  Decreased urine output

7.  Begin to feel thirsty

8.  Begin to become mentally irritated and depressed

9.  Eyes begin to become sunken

10. Skin begins to become wrinkled

11. May develop a stomach ache

12. May begin to experience lower back pain

13. Become dizzy,

14. Become mentally confused

15. As dehydration becomes severe the person slips into a coma and if the cardiovascular system collapses, the person dies.

These symptoms do not necessarily progress in that exact order and may vary between persons.

As little as 2% drop in body water can begin to affect your mental alertness as the brain begins to react to the fluid loss.  Dr. Kleiner, author of “Power Eating” states this 2% triggers fuzzy short-term memory, particularly trouble with basic math and focusing on the problems on the printed page or computer screen.  The problem is we are becoming dehydrated and we may not even feel thirsty yet.  We will begin to feel fatigued as our metabolism begins to slow down. 

Putting 2% into perspective:  A 150 lb. person would need to lose only 1.8lbs of water to be 2% dehydrated.  On a hot day you can lose that in less than an hour.

If, as they say, 75% of us are chronically dehydrated than we may be looking at a major contributing factor to maintenance error. And we don’t even know it.

Dr. R. Eichner of the University of Oklahoma states that: “The number one trigger of day time fatigue and poor performance is not lack of sleep or stress but dehydration.

In the Arctic, or any cold climate, dehydration is a seldom thought of as a problem.  Because it is cold we often don’t even think of drinking but in the cold the humidity is very low and we still lose water through breathing and other body functions.  The unknown dehydration leads to a feeling of fatigue and decreased mental alertness with never a though that a simple glass of water could make the person feel better. 

 What do we do?

Unlike fatigue, the solution is simple, very simple, drink lots of water.  The old eight, eight oz. glasses of water per day isn’t very accurate.  It doesn’t take into account, body weight, climate or activity.

 The Formula

 A more accurate figure calls for taking your body weight in pounds and dividing it in half.  That number is the oz. of water that you require daily.  To that, add 12 to 16 oz. for hot dry weather and a further 12 to 16 oz. if you are doing strenuous physical work. 

That is considered a minimum to be sure that you are not dehydrated.  Drinking more than that will do no harm as the kidneys maintain the correct water content and will simply “expel” the excess.  This excess is thought to reduce the chances of colon cancer by 45% and bladder cancer by 50%.  It is thought to help flush out the toxins or at least dilute them. Thus we would be wise to always drink more than the minimum.

If you are perspiring heavily, than you will want to also replenish some essential body salts that are being lost.  These are sodium, potassium, calcium bicarbonate and phosphate.  Salt tablets will help as will some vitamin tablets. 

“Gatorade” has made a fortune as a means of replenishing these salts. I understand that you can now buy “Gatorade” in crystal form very reasonably and it tastes like Coolaide. If you want to make your own “Gatorade” here is a recipe that will work and be a lot cheaper.

Start with:

1 liter (or quart) of water.

½ ml. (1/8 tsp) of salt.      

75 ml. (1/3cup) of sugar

100 ml. (1/2 cup) of orange juice

Add an optional crystal packet of any flavor you want.  If it has sugar already added to it, than skip adding sugar.

If you have a blender, you can even blend in a banana to help balance the potassium. 

Another optional addition is 100ml. of cranberry juice.  The acidic in cranberry juice is said to help the kidneys function better.

Now if it’s hot and you’re working out in the heat than you will need to drink about one of those per hour just to keep balanced.

You should also be drinking fluid about every 20 minutes in the above conditions in order to keep the fluid level balanced..

Another often forgotten source of fluid as well as some those missing salts are fresh fruits and vegetables.  They are made up of up to 90% water and are, as we know, good for you.

By fluid we mean, your “Gatorade” mixture above or plain ole water, milk, juice, mineral water and flavored seltzers but NOT tea, coffee, or alcohol.

Diuretics do not help Dehydration

When you are trying to replenish your body fluid level, tea, coffee and alcoholic drinks are not the answer.  In fact they make the situation worse because tea, coffee and alcohol are what are called “diuretics” and cause the kidneys to release more water, resulting in greater dehydration.  If you are going to drink coffee, tea or alcohol than you better add a water chaser to them just to counteract their diuretic effect.

One of the reasons a person can become “hungover” after drinking alcohol is because their bodies are dehydrated.  While it certainly isn’t the only reason, it at least is one that can be combated by drinking plenty of water with the alcohol.

One of the most common times for dehydration is in the morning.  We have expelled fluids from our body through the night and than we start the day with a diuretic called coffee. This results in a further loss of fluids shortly after.  We than begin to feel fatigued due to dehydration, so we go and have another cup of “pick me up” diuretic (coffee).  It is now easy to see how we can end up in the moderate dehydration range and not realize what the problem is.

Nonscientific Dehydration tests

Here are a couple of non-scientific tests that may assist you in figuring out if you are dehydrated. 

1.      Lick your lips and if they are dry and taste salty, there is a good chance you are dehydrated.

2.      Look at the color of your urine.  The darker it is from normal very pale yellow the more likelihood you are dehydrated.

3.      Pinch the skin on your arm.  If it does not go right back into shape than you may be dehydrated.  This seems to work best with older people and is an unscientific nurse trick.

      Thinking that you have somehow trained yourself to go without water is like training yourself to ignore a high water temperature indication in your car. The problem is there - you are just ignoring it.

The Journal of Sports Science reported that persons were able to work out 33% longer if they drank water while working out.

Please give this article some serious thought and remember; if we are to reduce maintenance error we have to use all means possible.  Here is an easy one to fix – if we just make the effort to do it.  Lets at least eliminate this potential source of error.  While the industry may not, at least your body will thank you for it.

Source: Gordon Dupont - System Safety Services