Instead of just drinking water, use a high sodium chloride drink - Glucolyte (1 sachet in 600mL water) - try homemade sports drink 1/4 to 1/2 teaspoon salt in 1L cordial - add 1/4 teaspoon salt to commercial sports drinks e.g. Gatorade, Powerade. Use salt tablets and take with a glass of water or cordial.