The facts you need to save your life

Rule #1 - you can’t drink too much water.
Rule #2 - too much salt will kill you eventually.

If you live by those 2 rules - and you exercise / work regularly in hot weather, read on, it just might save your health.

The truth is, too much water and not enough salt can kill you. Most people know that dehydration can cause serious health consequences. What most don’t realize is that too much of a good thing — WATER — can also be dangerous, even deadly.

They call it WATER INTOXICATION or more technically HYPONATREMIA. It happens when the body’s balance of salt and water become quickly diluted. It affects the production of nerve impulses, and impairs mental processes. Cells take on extra water and expand. As they swell, they put stress on the body’s organs, particularly the brain, which has little room to expand within the skull. Sometimes Hyponatremia is caused by an underlying medical condition.

Hyponatremia isn’t unique to the military. Indeed, marathon runners, tri-athletes, even high-desert hikers all can succumb. “Most people aren’t aware of the risk of drinking too much water,” said Bob Murray, director of Gatorade Sports Science Institute. Sport drinks are engineered to replace both salt and fluids depleted during exercise. Drinking sports drinks can help; but it alone can’t maintain adequate sodium levels for people engaging in rigorous, endurance–level activity.

The point is you need to replenish not only the fluids you lose when you sweat, but the salt as well. Nothing that comes out of your body is pure water. So you’ve got to replace it with both the salt and water, Not Just Water.

Water Intoxication typically occurs over 4 to 6 hours or more. It attacks participants in High–Endurance events, such as marathons, long road marches and triathlons in which participants swim, bicycle and run long distances in non–stop succession.


Sodium helps maintain the body’s electrical processes essential to transmitting nerve impulses and contracting muscles. When the body’s sodium content is depleted at the same time water level is increased, cells absorb more water and swell. Excessive water in the brain cells can cause seizures and in rare cases death.


(1) If you are drinking and drinking and still feel horrible you need to let someone know.

(2) Besides setting drinking limits, you can maintain proper sodium level by eating chow hall food or MRE’s.

(3) Follow Hydration Instructions based on Activity Levels as well as Temperature Levels.

The Problems with Hyponatremia is that conditions may be accelerated by some existing physical condition such as;

(1) Cystic fibrosis – a condition that causes a person to lose large amount of sodium through sweating.

(2) Another problem is that initial symptoms of Hyponatremia – dizziness & headaches are the same for Dehydration and Heat Exhaustion. But the repeated vomiting common with Hyponatremia usually doesn’t occur with dehydration or heat exhaustion. So if they are not making a rapid recovery and vomiting. It’s recommending that they should be evacuated because they might have Hyponatremia.

Although civilian fatalities are rare, most race directors have seen cases that presented with seizures or comas and had to be hospitalized and some times put on the ventilator. While Hyponatremia is preventable, it also is highly treatable. Depending on the severity; the condition can be corrected by eating salted food or in more serious cases; by administering Saline Solution directly into the blood stream with IV. But only a small percentage require hospitalization.

Note: IV should only be administered by qualified medical personnel.

To Much of a Good thing

People have assumed that it’s difficult or impossible to get too much of a good thing and that if you drink too much your kidneys will get rid of the excess water. That’s not necessarily true. On average, during rest the body can rid itself of 1 to 1 ½ quarts of water in an hour through urination. If you drink more than that per hour, in excess of what you need, the body will retain water and dilute body fluids.

3 key factors

Physical conditioning, genetics, acclimatization to heat determines how much sodium you lose through sweat. The better your physical conditioning and the better your heat acclimation the more sodium you will retain.

How much salt you need to consume depends largely on how active you are. Athletes and Soldiers who carry a full pack 10 miles a day needs more than those whose primary job keeps them behind a desk.

The American Heart Association recommends daily intakes of no more than 2,400mg. of sodium per day, about 1 ¼ teaspoon. But Murray said; "people who are active for more than a few hour can sweat out many times that amount".

While rate vary; Murray said that for an hour’s workout at the gym most people can sweat ¾ of a quart to 1 ½ quart an hour and sometimes twice that rate. The average person will sweat about 1 gram of sodium for every quart of sweat. So those amounts should be replenished through food and sport drinks.

But Don’t Stop drinking water, you just need balance.

To help maintain the proper fluid and salt level; its advised that you weigh yourself before and after heavy physical exercises. For each pound lost, drink 1 pint of fluid. But if you weigh more you’ve drank too much. Says Armstrong former president of American College of Sports Medicine.

Telling the Difference

Although the symptoms are similar in both dehydration and Hyponatremia, there are some differences. With hyponatremia the person is more likely to vomit repeatedly than someone suffering from dehydration is. Seizures are more likely also.

New Medical Evacuation Guidelines

If the person vomits at least twice, and hasn’t shown marked recovery after 1 hour of re-hydration and continues to generally deteriorate they need medical help.

Equal Opportunity Health Risk

In the general population hyponatremia seem to occur more often in women, but it also occurs in men. People who tend to become hyponatremic are vigilant water drinkers who maintain low– salt diets. As a rule of thumb people who drink more than 3 quarts of fluids a day need to be certain to get enough salt. The dietary guidelines that recommend watching salt consumption are great for couch potatoes. But when people are physically active the rules change. And don’t think you can maintain a low– salt diet and make–up for it with sport drinks. Sport drinks aren’t salty enough.

Tips to Prevent Hyponatremia

(1) Switch to a saltier diet in anticipation of High Endurance activity, whether it’s running a marathon or a long road march.

(2) Eat pretzels over the last half of a long race or march.

(3) Favor sport drinks over water and drink 5 to 8 ounces every 15 to 20 minutes.

(4) Young, healthy and very physically active people need salt. THE EXCEPTIONS: those with high blood pressures or kidney disease.

(5) Replace the fluid you’re losing while you exercise. The best thing to drink if you want to work hard and recover quickly isn’t water. It’s a sport drink that can replenish Electrolytes and Nutrients lost through sweat.

Hyponatremia symptoms

(1) Nausea and vomiting

(2) Disorientation

(3) Lack of coordination

(4) Headaches

(5) Dizziness

(6) Looks an awful lot like those of Dehydration

How too much water makes you sick

(1) Exposure to heat and exercise: The body cools itself by sweating, carrying sodium and water out through the skin.

(2) Drinking water only: Replenishing fluids by drinking only water dilutes the sodium level in the fluid surrounding the body’s cells.

(3) Cell reaction: The relative imbalance of sodium outside the cells causes them to absorb excess water, swelling their size. If this happens to rapidly, it can inflame the lungs, swell the brain and possibly cause death.


When temperatures climb, people need more rest and water to keep working. The work – rest cycles and amounts of water that the Army says are needed to sustain performance and hydration for at least 4 hours of work:

Source: u.s. army research institute of environmental medicine

Average service member wearing hot weather BDU’s

    Work/Rest Cycle (Minutes) Water Intake (Qts) Work/Rest Cycle (Minutes) Water Intake (Qts) Work/Rest Cycle (Minutes) Water Intake (Qts)
1 78-81.9 No Limit 0.5 No Limit 0.75 40/20 0.75
2 82-84.9 No Limit 0.5 50/10 0.75 40/20 0.75
3 85-87.9 No Limit 0.75 40/20 0.75 30/30 1
4 88-89.9 No Limit 0.75 30/30 0.75 20/40 1
5 >90 50/10 1 20/40 1 10/50 1

Examples of work intensities are shown below
weapon maintenance walking on loose sand2.5 mph, no load  walking on hard surfaces at 3.5 mph with more than a 40# load
walking on hard surfaces at 2.5 mph with less than a 30# load walking on hard surfaces at 3.5 mph with less than a 40# load walking on loose sand at 2.5 with load
rifle drills with load calisthenics
marksmanship training patrolling
individual movement techniques (low crawl)
digging foxhole

NOTE: you shouldn’t drink more than 1 ½ qts of water an hr. or more than 12 qts a day.

Return to The Alpha Group Web Page

Send Warlord E-mail.

All materials at this site not otherwise credited are Copyright © 1996, 1997, 1998, 1999, 2000 Trip Williams. All rights reserved. May be reproduced for personal use only. Use of any material contained herein is subject to stated terms or written permission.