3 questions about drinking lots of water

Who hasn't been drowned by the saying to drink 8 to 10 glasses of water a day? Turns out, that advice doesn't hold true, but that hardly makes water worthless. Here are some facts about water:

Yes. Studies show that drinking water, either with a meal or incorporated into the food (think soup), helps dieters feel full.

• After all, our bodies consist mostly of water, which makes up as much as 70 percent of our body weight.
• Water makes up 80 percent of our muscles and 75 percent of our brains. We need it to lubricate our joints and organs, regulate body temperature and transport nutrients.
• Some people swear by drinking lots of cold water because they say the body burns calories trying to warm the water.
• Studies have confirmed that drinking cold water does temporarily increase the body's calorie burn, but not by enough to make any difference. The real reason water may facilitate weight loss is that it helps people feel full, although no one knows how long the effects last or how much water is needed to keep you away from the fridge.
• A very small study conducted at the University of Kuopio in Finland found that when eight healthy women drank two glasses of water while they were eating breakfast, they felt less hungry than when they dined without water.
• A larger study conducted by PhD and author of Volumetrics, Barbara Rolls, and her colleagues found that consuming water as part of a food, as in chicken soup, appears to be more effective for curtailing appetite for the next meal than drinking water with the food.

Most people will replace the water they lose during a workout over the following 24 hours.

• If you're intent on making sure the amounts match up, weigh yourself before and after you exercise.
• For each kilogram (two pounds) you've lost, drink 500 millilitres (16 ounces/two cups) of fluid.
• Unless you've worked out for more than an hour in hot weather, skip the sports drinks.
• Heat and exhaustion are the two factors that make you lose large amounts of electrolytes through sweat. If you haven't experienced those two things, the food you eat afterward will restore any lost electrolytes.

The average person's kidneys can rid the body of nearly one litre (one quart/four cups) of water per hour.

• If you consume extremely large quantities of fluids, exceeding the kidneys' ability to excrete them, you can drink to excess.
• Water overload, or hyponatremia, is a rare condition seen almost exclusively in marathon runners and ultra-endurance athletes when they drink too much fluid and lose excessive sodium through sweat.
• This combination dilutes the sodium concentration in the blood, causing a potentially lethal condition that starts with symptoms like headache, confusion, vomiting and fatigue.
• If severe enough, hyponatremia can lead to seizures, coma and even death, but it usually requires three to four hours of fairly continuous exercise and continuous consumption of fluids.

In short, you probably won't consume too much water unless you're an athlete performing vigorous training. Besides that, a consistent amount of water is enough to quench your thirst and ensure your muscles are operating properly.