Aside from aiding in digestion and absorption of food, water regulates body temperature and blood circulation, carries nutrients and oxygen to cells, and removes toxins and other wastes. This "body water" also cushions joints and protects tissues and organs, including the spinal cord, from shock and damage. Conversely, lack of water (dehydration) can be the cause of many ailments.
Among its other benefits, water plays a major part in weight loss. Since water contains no calories, it can serve as an appetite suppressant and help the body metabolize stored fat. It may possibly be one of the most significant factors in losing weight. Water is the single most important nutrient you take every day. It's fat-free, cholesterol-free, low in sodium, and completely without calories. Also, drinking more water helps to reduce water retention by stimulating your kidneys. Studies have recommended that if you are overweight according to average height and weight comparison charts, you should add one glass of water to your daily requirement (of ten glasses) for every 35 pounds over your recommended weight.
Dehydration leads to excess body fat, poor muscle tone & size, decreased digestive efficiency and organ function, increased toxicity, joint and muscle soreness, and water retention. Increasing your physical activity increases your body's demand for proper hydration. While sports drinks claim to offer plenty of nutrients, they also have a lot of sugar, which can actually dehydrate your body even faster. Be sure to talk to your doctor or personal trainer to make sure you're getting enough water, and learn how much water you should be drinking once you begin a training or work-out regimen.