Hydration during exercise is important, but how much should we drink?
There is alot of mis-information around hydration during exercise. One of our Sport & Exercise Medicine Physicians, Dr James Lawrence, has recently published an article in Medicine Today on this topic.
In summary, if exercising for less than an hour, then drinking during activity is usually not required at all, and water afterwards to rehydrate is adequate. For longer duration exercise, particularly over 2 hours, some form of hydration, as well as some carbohydrate intake, can maintain performance. A sports drink can provide both of these, however they do not provide any particular benefit over water and a snack. In warmer weather more fluid may be required.
It is important to understand that too much fluid during endurance exercise can also lead to overhydration and dangerously low sodium levels (exercise associated hyponatraemia – EAH). EAH is associated with fatigue, confusion, loss of consciousness and even seizures.
The best way to guide fluid intake is based on thirst. Thirst is the bodies mechanism to maintain optimum fluid balance. Another option is to weigh yourself before and after exercise (with bare, dry skin) and start to learn how much fluid you lose in sweat whilst exercising in different weather conditions. This takes practice.