The Importance of Hydration

Between 50-75% of the human body is water, which means that there can be drastic consequences if a player loses water.

Dehydration occurs when the body loses fluid, which during exercise is mainly caused by sweating. The extent of fluid loss can be easily measured by weighing athletes before they start training then once they have finished. Each kilogram of weight loss indicates a loss of 1 litre of fluid. Athletes should be weighed in their underwear, as singlets and shorts will retain sweat.

In order to minimize dehydration, athletes need to drink enough during exercise to match the loss of sweat. Any amount of dehydration will impair the performance of the athlete, with some estimates suggesting that 2% dehydration can lead to a 10% decrease in performance.

Another test for hydration is the colour of an athlete’s urine – athletes should aim for it to be consistently colourless or light yellow. Dark yellow or amber coloured urine are signs of dehydration.

The level of dehydration can range from mild to severe, as can the symptoms that an athlete may experience, which include:

  • Dizziness or light-headedness;
  • Nausea or vomiting;
  • Muscle cramps;
  • Increased heart rate;
  • Increased rate of fatigue;
  • Reduced skill level.

Scheduling regular drink breaks during practice and ensuring that athletes have been informed of the importance of hydration are important steps for a coach to take. The coach should not simply call “drinks break”, but should ensure that every athlete does take a drink. Having a team rule that every player must have their own drink bottle at every training can help reinforce the importance of drinking.

Fluids that should be avoided are:

  • Carbonated drinks;
  • Drinks containing caffeine or other diuretic substances (which cause fluid loss).

Where exercise is of high intensity or lasts for an hour or more, the fluids consumed should ideally meet the following criteria:

  • Have a flavour palatable to the athlete (as this will encourage greater fluid intake);
  • Contain 6-8% carbohydrate;
  • Contain electrolytes such as sodium and potassium.