To avoid becoming dehydrated, it's best to drink plenty of fluids — as much as 2-3 cups per hour — unless you are exercising or outside in the heat, then you'll need to consume more.
Normal kidneys can release up to a quart of fluid every hour. Drinking more than that can be hazardous to your health.
The average adult needs between 3-4 litres of water each day but drinking more than 800ml within an hour could be putting your kidneys in danger.
You've probably heard the advice to drink eight glasses of water a day. That's easy to remember, and it's a reasonable goal. Most healthy people can stay hydrated by drinking water and other fluids whenever they feel thirsty. For some people, fewer than eight glasses a day might be enough.
The American College of Sports Medicine recommends drinking a total of 2 litres of water in 500ml amounts, every 20 to 30 minutes, instead.
taking all your water at once. It's important to make sure you replace more water than you lose during the day to maintain optimum hydration status. The best way to achieve this is by drinking water regularly throughout the day rather than consuming all your water requirements at a particular time during the day.
Bottom line: The kidneys can remove 20–28 liters of water per day, but they cannot excrete more than 0.8 to 1.0 liters per hour. Drinking more than this can be harmful.
"The kidneys have limitations of how much water they can excrete at a time, which is a maximum of 800 to 1,000 milliliters per hour," says Koskinen. "Anything that exceeds that amount essentially waterlogs the body."
When you're overhydrated, you will notice some swelling or discoloration of your feet, hands, and lips. When the cells swell, the skin will also swell. Weak muscles that cramp easily. When the electrolyte levels drop because of drinking too much water, your body balance goes down.
You need lots of water to replace what you sweat out. How much? Before you work out or spend time outside, fill up your bottle with 16 to 20 ounces of H2O. Drink 6 to 12 ounces about every 10-15 minutes while you're active.
Here is one more reason to enjoy that morning cup of joe: “Coffee counts toward your daily water intake,” says Lauren DeWolf, MS, RD, a registered dietitian with Sharp Rees-Stealy Medical Centers. The water in coffee, tea and other caffeinated beverages helps us meet our daily fluid needs.
At the most, you can absorb about one liter (approx 34 fluid ounces) of water per hour, but only in the most extreme heat and humidity. Most of the time you can only absorb about half or not too much over half that amount, even though it won't fully replace your losses.
Quickly gulping down water doesn't solve the purpose of having it. When you have it fast, the impurities that are supposed to go out get deposited in the kidneys and the bladder. Having water slowly and taking small sips can help in strengthening your digestive system and improve your metabolism.
You'll feel less hungry and may even lose weight. You'll probably experience more comfortable digestion (less heartburn). Bowel movements might be easier and more regular. Your teeth and gums will be healthier and more resilient.
Water helps the kidneys remove wastes from your blood in the form of urine. Water also helps keep your blood vessels open so that blood can travel freely to your kidneys, and deliver essential nutrients to them. But if you become dehydrated, then it is more difficult for this delivery system to work.
This is known as hyponatremia and it's caused by low sodium (salt) levels in the blood. It can occur if too much water is drunk over a short period of time. Hyponatremia sometimes affects athletes whose blood sodium level is reduced through sweat and then diluted by drinking large amounts of water.
Drinking little and often is the best way to stay hydrated. In the UK, the Eatwell Guide suggests you should aim for 6-8 glasses of water and other liquids each day to replace normal water loss – around 1.2 to 1.5 litres. Water, lower fat milk and sugar-free drinks, including tea and coffee, all count.
Daily fluid intake
The Eatwell Guide recommends that people should aim to drink 6 to 8 cups or glasses of fluid a day. Water, lower-fat milk and sugar-free drinks, including tea and coffee, all count.
Water is the ideal hydration choice because it moves quickly though your digestive system and into your tissues. Stay hydrated by sipping small amounts of water throughout the day; avoid chugging down fluids right before exercising to avoid stomach discomfort and bloating.
Chugging large quantities of water isn't hydrating you any more than if you sip it slowly. It can seem like you're being proactive by gulping down a large amount of water before beginning some extraneous exercise.
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.