Myth 1: You should drink 8 glasses of water per day.
In fact, the Institute of Medicine recommends approximately 125 ounces (15 cups equivalent) for men and 91 ounces (about 11.4 cups) for women. However this can include water from foods and beverages. The average person gets enough hydration unless there is heat stress or long periods of activity to upset the daily balance.
Myth 2: There's not much water in food.
In fact, the average person gets 20% of their daily water allowance from food. Considering an apple is 84% water, bananas are 74% water, broccoli is 91% water, a plain bagel is 33% water, ground beef is 56% water and American cheese is 39% water, staying hydrated should be a breeze.
Myth 3: You can exercise for hours before dehydrating in hot, humid conditions.
In fact, the average person gets dehydrated in 30 minutes when exercising outdoors in hot, humid weather. If you have to do it, take longer breaks, shorten the workout or intensity level and dress accordingly (i.e. light colored cotton).
Myth 4: Don't drink water until after the workout.
Not true. Not only should you drink about 16 ounces (2 cups of fluids) about 2 hours before working out, but you should also rehydrate about every 20 minutes. This can mean drinking 5-10 ounces of fluid every 20 minutes. Your exact need will depend on your age, gender and weight along with how hard you're working and whether you're indoors or outdoors.
Myth 5: You have to exercise to lose water.
In fact, you lose about 10 or more cups of water every day just living, breathing, sweating, urinating, etc. Eating and drinking is what makes up for this.
Myth 6: You should avoid drinks and snacks with sodium when trying to rehydrate.
Sodium is essential in rehydrating, either during or after exercise. That's why sports drinks contain sodium which is one of the electrolytes your body loses during exercise. These types of healthy sodium rich drinks and snacks also trigger thirst and help you to retain fluids.
Myth 7: There's no such thing as drinking too much water while exercising.
While some water rehydrates, too much water in a short period of time can be dangerous. Healthy adult kidneys process from 20 to 1000 ml of fluid per hour, so while it's not easy to overload them, it can happen. Weight gain, bloating, nausea and vomiting are all symptoms of water intoxication. The International Marathon Medical Directors Association recommends that athletes drink no more than 31 ounces of water per hour during extended exercise.
Myth 8: Water is just for quenching thirst.
In fact, the human body is 55% to 75% water and has water in every cell, tissue and organ. Water helps to move nutrients, eliminate waste, keep your temperature at the right level, lubricate and cushion joints, keep skin moisturized, sustain life.
References:
WebMD