The fastest method for rehydrating patients is the medical technique of intravenous (IV) fluid replacement. This sends electrolyte-balanced fluids directly into the blood stream so it gets distributed by your blood cells throughout the body almost immediately.
The fastest way to hydrate is with an oral rehydration solution. These products are packed with electrolytes which are minerals found in your body that balance fluid levels and maintain optimal hydration. While you can hydrate fast with regular water, focus on electrolytes.
Foods that hydrate you
Foods that typically provide the highest water content are raw fruits and vegetables. Eating a diet heavy in produce is a good way to give the body vitamins, minerals and fiber while increasing your daily water intake.
When you drink a glass of water, it takes approximately 15 minutes for your body to absorb the fluid. However, when you're dehydrated, it can take about three times as long (45 minutes) for fluids to make their way from the stomach into the bloodstream and to the rest of the body.
Drinking beverages that contain electrolytes can both rehydrate you quicker than plain water and it can keep you feeling hydrated longer than plain water.
Gatorade, because of its electrolyte content, helps to restore the lost electrolytes and keep a person hydrated, during intense activity. It can also replace electrolytes, during times of illness, such as stomach viruses.
Chugging as much water as you can all day is likely not the best or most efficient way to stay hydrated, and it's technically possible to overdo it. There is such a thing as overhydration that causes some unwanted and potentially dangerous side effects.
Milk is more hydrating than water
For example, milk was found to be even more hydrating than plain water because it contains the sugar lactose, some protein and some fat, all of which help to slow the emptying of fluid from the stomach and keep hydration happening over a longer period.
Best Overall: Gatorade
The levels of electrolytes (sodium and potassium) are moderate and sensible with 160 mg of sodium and 45mg of potassium per 12 fluid ounce serving. You can also find Gatorade varieties with higher sodium, zero sugar or no calories depending on your needs.
It hydrates you
This myth comes from a study funded by Gatorade that found people who drank their product were better hydrated than if they drank water—but only because they drank more fluids. If you drank the same volume of water versus Gatorade, you'd be equally hydrated.
Staying hydrated is so important on a daily basis, but even more so when it's hot and kids are so active! I've written a post about hydration here before because it's just so important. Anyway, moving on, Hydralyte have released a whole bunch of Electrolyte products for rehydration that you can use everyday.
Signs of dehydration include: Headache, delirium, confusion. Tiredness (fatigue). Dizziness, weakness, light-headedness.
In addition, Coke offers little in the way of electrolytes, and its carbonation is thought to increase the risk of gastric upsets during exercise. Finally, Coke's acidic content and artificial colours make the beverage in the red-and-white can an improbable choice for serious athletes.