The recommended level of fluid intake for an adult will vary depending on a number of factors including, body type, weather conditions and level of activity. The Department of Health recommends that 1.2 litres (8 x150ml glasses) of fluid should be consumed daily to maintain health. The body actually requires 2.5 litres daily but the shortfall can be obtained from food. These levels should be increased if a person is taking part in exercise.

Drinking before, during and after exercise is essential to keep the body functioning. Drinking fluid during and after exercise prevents significant dehydration and large changes in electrolyte balance. How much fluid will depend on how much someone sweats; this can be affected by the environmental conditions, the intensity type and length of the exercise session. The recommended level of fluid is 150ml every 15-20 minutes which is in addition to the recommended levels to maintain health.

For those people taking part in endurance activities it is suggested that they consume sports drinks which also replace salts and minerals that are lost through sweating. Water alone is not ideal for rapid and complete rehydration because whilst it replaces fluids it does not replace any minerals or electrolytes lost during exercise.