Adequate hydration is not only important for sports performance, it can also affect performance and attention span at work. Researchers are now on course to develop a hydration index to identify which drinks provide the most hydration.
Not all drinks are equally hydrating, and their individual composition plays a large role in influencing the rates they are absorbed by, and excreted from, the body.
The index could be the hydration equivalent of the Glycaemic Index (GI) which defines blood glucose response to the ingestion of food.
For the research, scientists at Loughborough University in Britain will test drinks including water, milk, orange juice, tea, coffee, regular and diet fizzy drinks and sports drinks.
"We want to quantify the differences between as many drinks as possible to be able to provide guidance on which provide the best levels of hydration," said Phil Cordery from Loughborough University.