NUTRITION INFORMATION - FLUID FACTS

Why is fluid intake so important for runners?

Fluid is a vital part of any athletes diet for three main reasons: it helps us to get rid of heat through the skin by sweating; it helps the body to get rid of waste products and toxins in urine and also helps to transport glucose in the blood to our muscles so that we can exercise. Without it the body can not perform at its best and a dehydrated runner will end up going nowhere fast.

Which fluid should I choose?

• Water is the most important fluid for anyone - runners included. It is easy to digest, quickly absorbed and, combined with a healthy sports diet, is the perfect fluid for anyone running for less than 90 minutes.

• Watery foods are another good choice for boosting your fluid intake. Eat plenty of fresh fruit, tomatoes, soups, cucumber and other snacks with a high water content.

• Sports drinks usually have some added extras in the form of either carbohydrate or electrolytes, the body salts lost through sweat. Studies have shown that carbohydrate drinks are most effective in intensive exercise which lasts for 90 minutes or longer, such as a marathon. But if you find a sports drink that suits you, there is no reason why you shouldn’t drink it on a more regular basis. Look for drinks which contain long chain polysaccharides - easily digestible carbohydrate - which is quickly absorbed. Added electrolytes are unnecessary in a sports drink since water and a good post race diet will replace them just as well.
  
  What is the difference between an isotonic sports drink and a hypotonic drink?
  
• Isotonic drinks contain particles of carbohydrate and/or electrolytes at the same concentration as the body’s own fluids which means they are absorbed into the blood stream at around the same rate as water.

• Hypotonic drinks contain particles that are less concentrated than body fluid which means they are more quickly absorbed by the body. It is thought that they increase the rate at which water is absorbed by the body and speed up the rehydration process.

• Hypertonic drinks are the third category of sports drink. They contain particles which are more concentrated than the body’s fluids and are absorbed more slowly. They are best used as a recovery drink or whenever you need extra energy during the day.
  
  How do I know if I taken in enough fluids?
  
  
• A simple way to test if you are drinking enough is to check the color of your urine. If it is bright yellow it is probably a sign that you aren’t drinking enough and your urine has become concentrated with metabolic wastes.

• Look out for warning signs that you may be dehydrated: feeling tired all the time, having headaches and general weakness could all be indications that you aren’t taking in as much fluid as your body needs.
  

  When should I drink in a race?

  Rule number one is to drink before you feel thirsty. The sensation of thirst is your body’s way of telling you that it is already becoming dehydrated - the last thing you need during a race - and you could have lost about one per cent of your body weight by then. Start drinking fluids as early as you can and then take a few sips every 15-20 minutes throughout the race - remember that in very hot or humid weather you might need to drink more.

What should I do if I become dehydrated in a race?

Unfortunately there is only one thing you can do and that is to stop running. If you don’t stop, your body will eventually make its own decision to call it a day. The only way around it is to make sure you are well-hydrated before you start and to keep topping up your fluid stores as you run.

Are there any fluids that I shouldn’t drink?

You should avoid alcohol and caffeine based drinks such as tea, coffee and cola which all promote dehydration. Fizzy drinks can cause bloating and some of the popular soft drinks, such as cola, are laden with sugar but contain very little else.