Warm weather is here.  If you work or train outdoors you can be exposed to high levels of heat, making proper hydration critical to performance and health.   Heat injuries can kill you.  The good news:  it is pretty easy to stay safe and healthy with a little fore thought.  Dehydration causes stupidity and injury, have a plan to avoid it.

Water accounts for about 60% of a man’s body weight, and 50% of a women’s body weight.  It makes up about 85 percent of the brain,  80 percent of blood, and roughly 70 percent of lean muscle.  The human body has been described as a bag of salt water.

A loss of 4% of your body’s water can cause athletic performance to drop by as much as 30%.  A loss of 9-12% of the bodiy’s water can be fatal.  Dehydration affects the body at the cellular level can cause headaches and joint pain.

If you over exert yourself in the heat without replacing fluids, you can die in a few hours.  We constantly lose water through sweat, urine, feces and even breathing. This water needs to be replaced in order for our organs to continue to work properly.   During exercise, or in a hot environment the body can lose about two liters of water per hour.

Water regulates your body temperature, dissolves vitamins, minerals and other nutrients so your body can use them. Water also enables waste removal which reduces stress on the kidneys and liver.

The Army makes soldiers carry Heat Injury cards like this:


 Mild Dehydration Symptoms

  • Daytime fatigue
  • Midnight hunger
  • Drop in athletic performance
  • Short-term memory loss
  • Trouble with basic math
  • Dry, sticky mouth
  • Decreased urine output
  • Headache
  • Constipation
  • Dizziness or light-headedness

Severe dehydration, a medical emergency, can cause:

  • Extreme thirst
  • Lack of sweating
  • Little or no urination — any urine that      is produced will be dark yellow or amber
  • Sunken eyes
  • Shriveled and dry skin that lacks      elasticity and doesn’t “bounce back” when pinched into a fold
  • Low blood pressure, Rapid heartbeat, Rapid breathing
  • In the most serious cases, delirium or unconsciousness
  • Lethargy and irritability
  • Vomiting and diarrhea

The final stage of dehydration is shock. This is characterized by blue-gray skin that’s cold to the touch. A severe drop in blood pressure produces this coolness.

Your thirst can be impeded by exercise and overridden by the mind, so thirst may not be the best indicator of your body’s need for water.  There is some debate about how much you need to drink.

The color of your urine is a much more reliable indicator of dehydration: Straw colored urine means you’re well hydrated, whereas a dark yellow or amber color usually signals dehydration. Vitamins, beets, and certain other foods and supplements can affect the color and odor of your urine

Shooting Outside?  Hydrate for Performance
Color chart from the Boy Scouts

Don’t start a workout or a mission dehydrated.  There are many things which can dehydrate you.  Avoid diuretics like caffeine and alcohol.  They provide fluid but cause an increase in urinary out put which dehydrates. We all wake up dehydrated because we haven’t had water in 8 hours or so.

We are striving for a state of euhydration (adequate hydration to meet your physiological needs).  This means that the fluid in your body will maintain appropriate body temperature, deliver nutrients, and maintain electrolyte balance. For every liter of fluid deficit, a heart rate can increase eight beats per minute, rectal temperature can increase by 0.3°C per minute, and cardiac output can decrease .

Hydrate during work, but realize you may not be able to keep up.  Factor this unavoidable dehydration in when planning your next work session.  Rehydration is best completed over twelve to twenty-four  hours.  Research has shown that consuming water with carbohydrates and/or sodium  can accelerate the absorption of fluids.

There is a great deal of controversy over sports drinks.  They have salt and sugar but in quantities much larger than you require.  Drink water for maximum hydration.  Sports drinks don’t hydrate better than water, but you are more likely to drink larger volumes, the quantity of liquid is the biggest factor for getting and staying hydrated.  Some experts recommend alternating water and sports drinks or diluting sports drinks by more than half.

The European Food Safety Authority recently upheld the claims that sports drinks hydrate better than water and help maintain performance during endurance exercise.  The bad news?   These effects only observed in extreme endurance sports.  The drinks don’t affect the typical person differently than water.

The British Medical Journal just published several articles on the subject:


To ensure adequate rehydration, consider monitoring body weight before and after exercise. For every pound of body weight lost, half a liter of fluid is recommended.  Make sure you are replacing electrolytes.  Your body craves them.

Brawndo: The Thirst Mutilator

There is a new kind of drink designed to support recovery.  Kill Cliff Energy & Recovery Drink was created based on the theory that an integral part of enhancing sports performance is reducing inflammation. By fighting inflammation, it readies you for the next work out.

Hyponatremia or “water intoxication” can be caused by overconsumption of hypotonic fluids, excessive loss of sodium through sweat, and extensive sweating while ingesting low-sodium fluids. To minimize the chances of hyponatremia, drinking something containing salt is recommended if you are working more than one hour .

How to maintain peak performance:

1.Hydrate before, during, and after your work out, while monitoring your hydration status through urine color. Under normal conditions, an average person needs 4 – 6 liters of water per day to stay hydrated.

2.During sustained efforts, consume a combination of sports drinks and water to provide adequate fluids and maintain blood sugar for sustained energy. Consuming cool, flavored beverages has been shown to increase fluid intake as compared to plain water consumption .

3.Monitor your urinary output and urine color.

If you’re in good shape and under ideal conditions, you can live for 3 to 5 days without any water at all.   Survival doesn’t mean you are healthy or performing mentally and physically.  Plan for hydration and win.

Photo by Destinee