Hydration and the active child: making sure your child has enough water

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

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Dehydration is when someone loses more fluids than they take in. When someone becomes dehydrated, it means the amount of water in their body has dropped below the level needed for normal body function. In hot weather it can be very easy for active children to become dehydrated. Some may even suffer heat exhaustion or even heat stroke.  A child is more likely to be affected if they are involved in at least an hour of high intensity physical activity on a hot day. Some examples of high intensity activity include team sports (for example soccer, football or netball), running or tennis.

Most children do not stop to drink as much as adults do.   They may only stop to drink when they are very thirsty. By this time, children can already be mildly dehydrated.

What is the best drink to have?

  • Water should always be the first choice. Children should be encouraged to keep a water bottle with them at all times and to stop and drink during activity.
  • Drinks that contain some carbohydrate (sugar) and extra salts (such as sports drinks) can be useful, but are not always needed.
  • Children who are involved in high intensity activity for over an hour, 2-3 times a week may benefit from using sports drinks.
  • Have chilled water and sports drink with you on a hot day when children are involved in high intensity exercise. This will help to keep them hydrated and happy
  • Sports drinks may be useful during exercise but are not a good choice for general drinking. They are high in sugar and can promote excess energy intake. Water is the best choice!
  • Be careful when choosing sports drinks. Some “energy” type drinks may contain other additives such as caffeine. These are not suitable for children.

How much to drink?

  • It is hard to work out how much fluid an active child needs on any one day. This is because different amounts of fluid are needed based on the weather and the intensity of the exercise. As a guide:
  • A younger child (under 10 years) will need about 200mls of fluid at the start of exercise and at least 100mls for every 20 minutes they are involved in physical activity. This is equal to about a 300ml bottle of water or sports drink every hour.
  • Older children (10 years and above) will need double this amount. They will need about 400mls of fluid at the start of exercise and at least 200mls for every 20 minutes they are involved in physical activity. This is equal to about a 600ml bottle of water or sports drink every hour.



  • Active children should be encouraged to drink regularly to make sure they do not feel thirsty.
  • Regular drink breaks during exercise are very important.
  • Water should be the main drink for your child.
The Children's Hospital at Westmead
Sydney Children's Hospital, Randwick
Hunter New England Kids Health

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