Keep those Fluids RollingRehydration requires not only the replacement of fluids, but also the electrolytes lost in sweat (especially sodium). Generally our diet contains far more sodium than we need, so over time sodium losses will be met.
Rapid rehydration of large sweat losses is assisted by drinking a salt-containing drink (eg sports drink or a commercial rehydration solution) or by including a salt rich food in recovery snacks or meals. This might include bread, breakfast cereals or pretzels or salt added in cooking.
Generally you will need to consume a volume that is 1.5 times your fluid deficit to completely restore fluid balance- for example, an athlete who is 2 kg lighter at the end of a work-out will need to drink 3 litres of fluid over the next hours to ensure full rehydration.