badminton klub BIT

The body can o­nly partially regulate water balance through the sensation of thirst as thirst is quenched before a sufficient amount of fluid has been drunk. In o­ne study where subjects exercised in hot surroundings and were allowed to drink as much as they wanted, it was found that o­nly 70% of the fluid needed to restore the loss was consumed. In another study, the fluid intake of three groups of soldiers marching in a temperature of 25°C was monitored.

The first group was not allowed to drink at all, the second group was allowed to drink as much as they wanted, and the third group was instructed to drink at regular intervals. When the performance of these groups was evaluated, it was found that the first group performed the worst; the third group, who also drank the most, performed better than the other two groups. These studies show that in order to maintain fluid balance, more fluid has to be drunk than just satisfies the sensation of thirst.

The colour of urine is a good indicator of the fluid balance and the need for water. If the body is dehydrated, the amount of water in the urine is reduced and the colour becomes a stronger yellow.

When to drink

Before a match

It is important that the players are not dehydrated before a match. The players should begin the process of topping-up with fluid already the day before a match. For example, an additional litre of juice can be drunk o­n the evening before a match, which will also provide an extra supply of sugar.

If more glycogen is stored in the muscles before a match than normally, the amount of water in the body is elevated, as glycogen binds water. An extra 200 grams of muscle glycogen, as a result of a high-carbohydrate diet, will increase body fluids by more than half a litre. This will help to reduce the net loss of water during a match, so also in this aspect a high carbohydrate intake the days before a match is advantageous.
The intake of coffee should be limited as coffee contains caffeine, which has a diuretic effect and causes the body to lose a larger amount of water than is absorbed from the coffee.

On the day of the match, the players should have plenty to drink and be encouraged to drink even when they are not feeling thirsty. However, during the last hour before the match the players should not have more than 300 ml (a large cup) to drink every 15 minutes.

During a match

During a match small amounts of fluid should be drunk frequently. It is optimal to drink between 100 and 300ml with a 2-3% sugar concentration every 15 minutes. This will give a total fluid intake of between o­ne and two litres, plus 30 to 50 grammes of sugar during the match. This is sufficient to replace a significant amount of the water lost through sweat, and to satisfy some of the demand for sugar. Although fluid intake during a match is important, it should not interfere with the game. Ingesting fluid at a critical time during a match may disturb the playing rhythm, so players should o­nly drink when there is a natural pause in the game.

After a match

In a study the water balance of some players was measured after a match. Determinations of body weight before and after the match showed that the players had a fluid loss of 1.5-3.0 litres corresponding to 2-4% of body weight during the match. Although the players were advised to drink plenty of fluid after the match, o­nly half the lost water was replaced during the first four hours, and it took almost ten hours before the fluid balance was fully restored. Other studies have similarly demonstrated that restoration of fluid balance is a slow process. These observations show that it is not sufficient merely to increase fluid intake immediately after a match. It is not unusual that players are partially dehydrated o­n the day after a match.

Summary

The following recommendations regarding fluid intake may be helpful for a badminton player:

1. Drink plenty of fluid the day before a match and o­n the day of the match - more then just to quench thirst

2. Drink frequently just before and during a match, but o­nly small amounts at a time - not more than 300ml of fluid every 15 minutes.

3. Drinks consumed just before and during a match should have a sugar concentration lower than 3% and a temperature between 5 and 10°C. The addition of salt or other substances is not necessary.

4. Drink a lot after a match even several hours afterwards. [I don't think they mean in the bar though!!]

5. Use the colour of the urine as an indication of the need for fluid the more yellow the urine, the greater the need for fluid intake.

6. Experiment with drinking habits during training so that any difficulties in absorbing fluid during exercise can be overcome.

Taken from badders.com