WATER IS VITAL !

The human body contains about 70% water. A reduction in body water will cause a reduced efficiency in cellular function. Soccer players have been shown to lose 1-5% of body weight through sweating (up to 4.5 kg in hot humid conditions) which results in impaired performance. Controlled studies show that a reduction of one percent in body weight can result in a ten percent reduction in work capacity (although individuals do show differences in body mass loss as some may have a better thermoregulatory capacity).

Furthermore, evidence shows that body mass loss will also cause mental functions to deteriorate perhaps resulting in players making mistakes. It is therefore important that any sweat loss is adequately and promptly replaced through fluid intake, whether this is through water or sports drinks. Figure 1 gives a general idea of how increased body water loss reduces performance capacity.

Dehydration will have a more immediate effect when playing or training in hot humid environments. Fluid replacement is extremely important to ensure players do not become dehydrated and to prevent any risk of heat injury. Weighing players before and after performance may be useful to evaluate weight loss. Thirst is never an adequate indicator of the physiological state of dehydration. Players should always be encouraged to drink more than their thirst indicates. Thus, correct fluid intake practice is extremely important.

Water has been shown not only to be useful in preventing dehydration. A scientific study demonstrated that it could actually help improve sprinting capacity in the second half of matches when compared to players who did not drink any water. Water is extremely useful in preventing dehydration, especially in hot conditions and is an excellent replacement fluid (In hot conditions, it is more important to rehydrate the player than to provide additional energy). For every 1 kg decrease in body weight - replace with 1 litre of fluid. A player's urine should be a diluted, pale colour. If it looks deep yellow, he should drink more. However, the consensus view is that a sports drink, which contains an energy source in the form of carbohydrates along with electrolytes, is more effective in maintaining performance.

Drinking carbohydrate solutions and commercial sports drinks have been shown to aid rehydration and improve playing performance. Carbohydrate (CHO) ingestion may improve performance by slowing the onset of fatigue through the sparing of muscle glycogen utilisation by increasing blood glucose levels (the primary aim), promoting muscle glycogen resynthesis and increasing post-match recovery.

This is especially useful if extra-time occurs and when regular matches limit the time available for fully restoring glycogen stores (can be up to 20 hours). For example, players who consumed CHO solution before a match and at half-time covered greater distances in the second half than those who did not.

The ideal sports drink should have 5 major qualities:

1. Tastes good

2. Rapidly absorbed

3. Causes no stomach discomfort

4. Helps maintain body fluid volume (prevents or reduces dehydration)

5. Has the potential to enhance exercise performance (delays fatigue).

 Conclusion

1. Drink plenty or increased amounts of fluid the day before and on match day.

2. Do not consume a CHO drink 1 hour before the game. Prefer 2 hours before as well as immediately before kick-off. Consume small quantities of fluid at regular intervals during the match. Solutions of 3 - 10 % CHO are generally advised.

3. Drink a lot straight after the game and even for a few hours afterwards. Avoid alcohol and caffeine intake (the same goes for before the match).

4. Both water and CHO sports drinks are useful in preventing rehydration and the latter will also help in preventing the onset of fatigue.

5. Always experiment with drinking habits in training, never on match day.

6. Always drink more than thirst indicates and pay particular attention to fluid replacement in hot humid conditions.