Hydration: Why is it so important?


Hydration: Why is it so important?

Whether you are exercising or not, your body needs fluid to function. I have composed an article from information I gathered that will help you understand when, what and how much you should drink to stay hydrated. I will also briefly describe the advantages of some types of sport drinks, when is best to use them and include some recipes for making your own!

Why Stay Hydrated?

Dehydration occurs when your body loses a large amount of the fluid that it requires to function and regulate your body temperature. The current belief (though not an entirely shared one) is that just a 2% drop in weight will affect performance. Symptoms of severe dehydration include fatigue, headaches and loss of appetite, feeling excessively hot, light headedness, nausea and just being sluggish. It is important to note that just being slightly dehydrated is not believed to harm health or exercise performance. The best way to recognise your level of hydration is, delightfully, by assessing the colour of your urine. If you produce dilute, pale/yellow coloured urine consider yourself hydrated! However if you produce a sample that is of little volume, concentrated and dark-coloured you are dehydrated. Don’t worry just pour yourself a glass of water and sip it slowly.

Can I be Over Hydrated?

Yes! This is called Hyponatremia or water intoxication and can sometimes occur with long distance runners. If you drink too much water during long bouts of exercise the water content of the blood increases and the sodium levels become diluted. This combined with the salt lost through sweat can have dire consequences. The best advice to avoid this is simply to listen to your body and drink according to your thirst. Also the using of the correct type of sports drinks to replenish sodium levels can aid you here.

I am not exercising today how much should I drink?

There is no doubt that maintaining your fluid levels is important. However the common belief that 8 glasses of water a day to stay healthy is a myth and there is no clear evidence to support this. How much water you need depends on many things, such as how active you are, your body type and the climate you live in. On a normal non-exercising day 1.5 to 2 litres of water should keep you hydrated.

Choose Still or Carbonated Drinks?

It has been found that both types will hydrate you to a similar level. However carbonated drinks tend to produce a possibility of mild heartburn and many athletes found that they made them feel full and ‘gassy’. This could limit how much they drink during exercise.

Sports Drinks vs Water

When fluid losses are relatively small, such as during low/moderate-intensity exercises such as easy pace swimming and cycling carried out for under an hour, water is sufficient to replace and rehydrate the body during exercise and there is little benefit to consuming a sport drink.

Sport drinks come in handy during high intensity exercise lasting less than or more than an hour and endurance based exercise lasting over an hour. There are 3 types of sport drinks:

Hypotonic – Often marketed as ‘lite’ drinks are quickly absorbed containing less minerals and carbohydrates than human body fluids. This makes them good for quick hydration but not ideal for prolonged exercise use.

Isotonic – This is your typical sports drink containing carbs and minerals similar to human body fluids. It absorbs similar to water and will contain 4-8g carbohydrate/100ml. A good compromise between hydration and refuelling!

Hypertonic – These are your soft drinks such as Lucozade energy and have higher minerals and carbs than human body fluids so they are absorbed more slowly. Not ideal during exercise but good for replenishing glycogen stores afterwards. It is worth noting that a lot of these drinks are also very bad for your teeth!

Can I make my own Sports Drink?

Definitely! Branded sports drinks are extremely expensive for what they are. Find some recipes for making your own 1L sports drink below. If you don’t think you can drink a litre you probably don’t need a sports drink.


Isotonic homemade Sports Drink

  • 40 – 80g Sucrose
  • 1 L – Warm Water
  • 1-1.5g (1/4 tsp) Salt
  • Sugar free/low calorie squash for flavouring if you like


  • 200ml fruit squash (eg. Robinsons)
  • 800ml water
  • 1-1.5g (1/4 tsp) Salt

Reference: The Complete Guide to Sports Nutrition 7th edition