8 x 8 is the rule of thumb: 8 glasses with 8 ounces of water a day. This keeps you well-hydrated and allows the body and brain to function at their best. Every system in your body needs water. In fact, it makes up 60% of body weight. Even mild dehydration can cause headaches, nausea, irritability and fatigue. You may need more water in hot temperatures, if you sweat a lot or if you are taking certain medications that increase urination. If you’re getting enough water is you’ll rarely feel thirsty and urine will be colorless or slightly yellow. Dark yellow urine is a sign of dehydration.
Can you drink too much water?
Though you can drink too much water, most people aren’t in any danger of it. Water drinking contests and endurance athletic events are about the only times “water intoxication” occurs.
At water drinking contests people drink excessive amounts of water in a short period of time, flooding their systems with more water than they can handle. It is extremely uncomfortable and no one would ever do this under normal circumstances.
When people sweat for excessively for more than an hour at endurance events or doing hard physical labor, it is important that they rehydrate with sports drinks or they run the risk of depleting sodium levels. Here’s how:
- Use sports drinks during hard physical labor or long distance, high intensity events (more than 60-90 minutes long).
- Eat more salt several days prior to competition (except for those with high blood pressure).
- During a marathon a good rule of thumb is to drink about 1 cup of fluid every 20 minutes.