The Claim: Chugging water during a workout is less hydrating than sipping normally. The Truth: “There is no scientific evidence indicating that "chugging" water is less hydrating than sipping it. If water is consumed it will help hydrate the body. However, the body's ability to retain fluid consumed depends on several factors including sodium intake. The most important point to remember isn't how you consume fluids but instead consuming enough total fluid and electrolytes to maintain proper hydration."
The Claim: Cold water speeds metabolism. The Truth: "There's little research on this topic, but according to one study, drinking cold water may have a very small effect on energy expenditure (calories expended). But drinking cold water versus room temperature water will likely have no effect on weight loss."
The Claim: Caffeinated drinks actually dehydrate you. The Truth: "This myth has been perpetuated for years, despite the fact that it was disproven more than a decade ago in a study published in the Journal of the American College of Nutrition. I'm not suggesting that someone should drink only energy drinks or coffee for hydration, because there's an upper limit of caffeine that will cause the shakes, jitters, etc. But caffeinated beverages do not contribute to dehydration."
The Claim: Drinking a glass of water in the morning before breakfast "cleanses" the system. The Truth: "The body's organs are what 'cleanse' the body and get rid of waste and toxins. However, water is essential for every cell, tissue, and organ in the body and, therefore, water does play a role in helping rid the body of waste through urine, bowel movements, and sweat."
The Claim: Room-temperate water is best for your body. The Truth: "The best temperature is that which will encourage a person to hydrate. There is no optimum temperature."