Intense work or exercise in the heat and serious illness can quickly lead to dehydration. Drinking lots of fluid with electrolytes can prevent it. 

The brain is 85% water, and an adult loses 10 cups of fluid each day, even without exercising. In order to keep the brain working at its optimal function, adequate water is needed.

It is well accepted that when working or exercising outdoors in hot temperatures or experiencing illness (such as vomiting and/or diarrhea), it is essential to stay hydrated and that the simplest solution is to drink plenty of water or an electrolyte-fortified beverage. Despite all of the attention focused on the dangers of dehydration, many people are unaware of this all-too-common condition, which can be fatal if one doesn’t recognize the signs.

This article explains:

  • Why water is so important
  • What dehydration is
  • Who is at risk
  • The three stages of dehydration
  • What electrolytes are
  • How electrolytes, when coupled with fluid replacement, can prevent and treat dehydration.

Water: The Most Important Nutrient

Water is the most important nutrient for your body. On average, the human body is 60 percent water by weight, depending on certain factors such as age, gender, and body weight. The average 70 kilogram (kg) man is made up of 42l of water while the average 55kg adult female is made up of 27.5l of water.

Within the body, water is divided between two major fluid compartments: 40 – 50% of total body water is contained within the cells, called intracellular fluid; 50 – 60% is outside the cells (extracellular fluid).

So, why is water so important?
It performs numerous important biological functions in the body:

  • At cellular level, water provides structural firmness.
  • Water makes up blood, lymph, gastric secretions, and urine.
  • It helps lubricate our joints (synovial fluid), which allows bones to move freely against each other.
  • It also forms blood plasma, which transports oxygen, glucose, and amino acids to active muscle and tissue while carrying away carbon dioxide and lactic acid.
  • During exercise, muscles produce lactic acid (plus other acids), and too much lactic acid can impair muscle contractility and performance.
  • Water helps maintain core body temperature (thermoregulation). The body uses water as a cooling mechanism (through sweating) to adequately control its temperature. Even in moderately warm weather, significant amounts of water are lost through sweat. Under more arduous training OR working conditions, it’s estimated that sweat losses in endurance athletes, and in miners working in pits or smelters, exercising or performing active work tasks in heat and humidity can be as much as 3l per hour.


Dehydration Defined

Even a mild deficit of water can have a substantial impact on well-being, exercise performance, work performance and attentiveness.

Definition of dehydration: This is the loss of body water and important ions (blood salts like potassium and magnesium). It simply means that the body doesn’t have as much water and electrolytes as it should have, which interferes with normal body processes.

It’s easy to become dehydrated, and one doesn’t have to run a marathon to become dehydrated. Each day the human body loses approximately 2 – 2 ½ cups (450 – 600 ml) of water just carrying out usual activities. It is therefore important to replace fluid losses throughout the day. Coffee, tea, and sodas are not an ideal choice. These beverages have a diuretic effect (i.e., trigger water loss) and actually increase the daily fluid requirement.

The current RDA for water for adults at rest under average conditions of environmental exposure is 1 ml/kcal of energy expenditure. For women, this equals 2.2 l/day; and for men, 2.9 l/day.

Who’s At Risk?

Any individual can become dehydrated from the following conditions:

  • Excessive sweating (e.g., endurance exercise, working outdoors, working in hot furnaces / smelters etc.)
  • Vomiting and/or diarrhoea
  • Fever
  • Excessive urine output (e.g., uncontrolled diabetes, diuretic medications).

If an adult is showing signs of dehydration (see below), one should seek medical attention immediately.

There are three classifications of dehydration: mild, moderate, and severe with each classification based on the amount of fluid lost from the body and not replaced.

Mild Dehydration

  • Dry lips and mouth
  • Thirst
  • Inside of mouth slightly dry
  • Low urine output; concentrated urine appears dark yellow
  • Moderate Dehydration

Moderate Dehydration

  • Thirst
  • Very dry mouth
  • Sunken eyes
  • Tenting (pinch and lift skin lightly—if it doesn’t bounce back readily)
  • Low or no urine output
  • Not producing tears
  • Severe Dehydration

Severe Dehydration

  • Rapid and weak pulse
  • Cold hands and feet
  • Rapid breathing
  • Blue lips
  • Lethargic, comatose, seizures
    Severe dehydration requires immediate hospitalization.

How to Monitor Hydration Status

Thirst is a signal that your body needs fluid; however, it’s a poor indicator of your body’s fluid needs because one can lose two percent of one’s body weight before one feels thirsty.

A better way to gauge hydration status is to monitor the output and color of the urine. A well-hydrated individual should void 1,000 to 1,500 ml/day, and urine color should be no darker than a pale yellow color. If the urine is darker, it is a sign that one is dehydrated, and fluid intake needs to be increased.

Dehydration’s Effect on Exercise Performance and Work Performance

Those who work and exercise in intense temperatures need to stay hydrated. Shift workers and endurance athletes should rely on urine output and color or checking their body weight both before and after each shift / exercise session / event to gauge water losses. Ideally, workers and athletes should replace approximately 1 litre of water per kg of weight lost.

Even mild water losses can significantly impede performance. For every one percent of body weight lost, blood volume decreases by 2.5 percent, muscle water decreases by one percent, and the body’s core temperature can increase 0.4 to 0.5° C. Changes in blood volume during prolonged physical labour / exercise impair the body’s ability to deliver oxygen and key nutrients to active muscles, organs, and glands and negatively affect thermoregulation (the body’s ability to regulate core body temperature) by diminishing the body’s ability to expel heat. Losses of three percent are associated with physiological changes, such as decreased blood volume, decreased urine output, diminished performance, and decreased endurance, while losses of nine to twelve percent are fatal.

What Are Electrolytes?

No discussion of dehydration would be complete without an explanation of electrolytes and their respective functions. Most people, when asked, aren’t sure what electrolytes are or why they’re so important in preventing dehydration.

Electrolytes are certain minerals (i.e., calcium, chloride, magnesium, potassium, sodium ions) essential to human health. As an essential mineral, an electrolyte cannot be substituted by any other nutrient in the diet.
This means that our bodies will only accept that particular mineral or electrolyte.

Without electrolytes, one cannot move, think, or live.

Within the body, electrolytes are dissolved in body fluids. In terms of hydration, electrolytes are responsible for directing water (and nutrients) to the areas of the body where it is needed most; and maintaining optimal fluid balance inside the cells. Besides maintaining fluid; and also electrolytes help our muscles to contract and relax and assist in the transmission of nerve impulses from the nervous system to different body parts.

The table below explains the important functions electrolytes perform in your body:

Table 1. How Electrolytes Help Prevent/Treat Dehydration 



Maintains water balance;

Activates thirst response;

Prevents water intoxication & hyponatremia



Enables normal muscle contraction



Influences performance of other minerals;

Enables nerve impulse transmission

Maintains normal blood pressure



Maintains water balance



Stimulates metabolism of proteins &


Helps muscles use glycogen, their main source of




Prevents muscle fatigue;

Enables normal muscle contraction;



Influences performance of other minerals;

Enables nerve impulse transmission;

Maintains normal blood pressure


Maintains water balance;

Prevents dehydration



Helps the body break down protein, absorb

minerals & vitamin B12



Enables normal muscle contraction & relaxation



Enables nerve impulse transmission



Enables nerve impulse transmission

In a supplementary drink consumed: it is essential that a balance of ALL electrolytes is necessary to maintain optimal hydration and endurance. Not only does one lose sodium in sweat, but one also loses other critical electrolytes like magnesium, and since most people don’t get enough magnesium, serious deficits can be occurring.

Shift workers exposed to long hours of intense heat and physical labour cannot rely on plain water and commercially-available high-sugar sports drinks to meet the body’s hydration and electrolyte needs.

Plain water doesn’t contain a substantial quantity or balance of the essential electrolytes required to stay adequately hydrated, replace electrolytes lost in sweat, and maintain optimum performance. As for sports drinks, the high-sugar content of most of these beverages often causes bloating, stomach cramps, and can impair performance at the moment when it may matter the most.

BACK TO BASICS-NUTRITION Lifestyle Nutrition Supplements include a carefully formulated electrolyte solution, which, when provided in the drink format (i.e. is mixed with clean water), powers rapid hydration and quickly replaces ALL lost electrolytes—not just sodium. It supports performance, stamina, and recovery, and delivers electrolytes evenly to ensure optimal hydration.

Lifestyle Energy Drink: 46g serving Lifestyle Low GI Milkshake: 100g serving
60mg Sodium 460mg Sodium
62mg Potassium 133mg Potassium
54mg Chloride 118mg Chloride